[求助]镀锌管可以焊接吗?

jyzhangbin · 发表于 2005-6-20 17:59

我们做一个粗真空管道，采用镀锌管，可是监理不同意焊接，请问有无镀锌管可以或不可以焊接的依据？

IMWORKMAN · 发表于 2005-6-20 18:56

这个问题的讨论非常热烈，跟贴达7页之多。但是也带来了一个问题，就是大家一般没有耐心看完这全部7页，导致一些很有见解，有理有据的跟贴被忽略。为了方便大家，下面对跟贴进行分类，分正方、反方。如果大家认可这种方式，今后对一些回帖数量大的题目也可用这种整理。赞成方：1．  可以焊接，只是镀锌层被破坏。2．  我的管道是无缝管,买回来后送外协热镀锌,后来因需要,也焊接了一部分,就是破坏了镀层,并无大碍。3．  镀锌管可以焊接，如现场修改、管子连接中间采用套管等都必须现场切割并焊接，焊接完毕后，应清理焊接处的表面，并刷上富锌底漆就可以了。4．  管子能否焊接与其是否带有镀锌层无关，只要管子材料的焊接性能良好即可。镀锌层是用于管道防腐的，且仅覆盖在管道材料的表面。由于焊接时镀锌层经常产生飞溅，因此，操作工需做好防护。我们公司以前经常处理镀锌零件的对接焊问题。可先将焊口处的镀锌层清理掉后进行焊接，然后再在焊口处涂上防腐材料。5．  镀锌管在要求不高情况下可以焊接，不过要先用气焊烧去焊接区的镀锌层，不然肯定要漏。焊完了可以用富锌漆防腐。这个在施工时干过，当时是一位高压焊工给焊的，第一次没有处理，结果试压时所有焊口全有沙眼。那位师傅脸上下不来，就用气焊烧了一遍，割掉重焊。接受教训后后边的焊口全部处理，再没有出现问题。6．  可以焊接，但是焊接之后要重新镀锌——有热浸镀锌和冷镀锌两种，最好能用热浸镀锌，这样防腐层会好一些！就是预制好了以后拿到工厂里面去镀锌。7．  可以焊接，镀锌管本来就是焊接管，为了保护焊接口可能要做外防腐．  反对方：1．   如果焊接，为什么还要用镀锌管。用普通焊管就可以了。2．  镀锌管由于炭含量较高，因此其焊接质量不好，一般情况下不能焊。3．  建议不对镀锌管进行焊接，镀锌管连接建议是用法兰或卡箍连接。如果实在要进行焊接，需焊后作热镀锌处理（一家之言仅供参考）4．  尽量不要焊接，如果非得焊接，焊接后再做镀锌等防腐处理。其实丝口也破坏了电镀层，也是要做防腐处理的，不过国内一般都不做了。5．  在消防工程工程中,规范中明确规定热镀锌管采用丝接或法兰连接.6．  多大的管子啊？一般情况下不采用焊接方式；但是如果非要焊接就会破坏镀锌防腐层；那就需要进行重新镀锌了，方法有两种：一种是预制好以后拿到厂家热镀锌，另一种方法就是重新冷镀，就是喷镀锌漆！7．  不能直接焊接的，焊完后容易损失镀锌层，导致容易产生腐蚀8．

[此贴子已经被作者于2007-7-9 0:24:12编辑过]

lhl · 发表于 2006-10-4 20:01

<span style="FONT-SIZE: 16pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">城市燃气输配镀锌管的焊接质量控制 摘要：本文探讨了镀锌管的焊接工艺及焊接质量控制方法，对保证燃气输送的安全提供了保障关键词
：镀锌  焊接
质量控制<span style="FONT-SIZE: 14pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">一、概述<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 21pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 2.0gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌钢广泛运用于各行各业,
<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">采用<span style="FONT-SIZE: 14pt; COLOR: #cc0033; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">钢的好处是利用在空气中能够形成致密氧化物保护层的金属锌来保护内部的钢结构。在被焊接、划伤的情况下，由于Zn-Fe<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">原电池的存在，相对活泼的<span style="FONT-SIZE: 14pt; COLOR: #cc0033; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">部分可以作为牺牲阳极，延缓钢铁的锈蚀,<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">同时各个结构死角均能到达,<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">耐腐蚀性良好。在西气东输工程末端市场--<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">居民用户楼栋输气中,<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">大量采用了镀锌管。由于传统的镀锌管丝扣连接容易泄露,<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">造成维护工作量大,<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">明装管影响建筑外观等缺点，寻求新的连接方式是必然的选择。焊接由于其密封性好，强度高等优点为部分城市燃气工程所采用。然而由于镀锌层的存在，在焊接中容易产生裂纹、气孔、夹渣，使较难得到良好的焊接质量。因此，怎样保证焊接质量，成为镀锌管安装的一个关键。

lhl · 发表于 2006-10-4 20:01

<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">二、镀锌钢的焊接特点<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌钢一般是在低碳钢外镀一层锌，镀锌层一般在20um<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">厚。锌的熔点在<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="419" unitname="°C">419°C</chmetcnv><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">，沸点<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="908" unitname="°C">908°C</chmetcnv><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">左右。在焊接中，锌熔化成液体浮在熔池表面或在焊缝根部位置。锌在铁中具有较大固溶度，锌液体会沿晶界深入浸蚀焊缝金属，低熔点锌形成“液体金属脆化”。同时，锌与铁可形成金属间脆性化合物，如Fe3Zn10<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">（δ<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">相）,FeZn10<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">（ε<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">相）等(<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">见图1)<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">。这些脆性相使焊缝金属塑性降低，在拉应力作用下而产生裂纹。如果焊接角焊缝，尤其是T<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">形接头的角焊缝最容易产生穿透裂纹。<p class="MsoNormal" align="center" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 24pt; TEXT-ALIGN: center; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"> <p class="MsoNormal" align="center" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: center; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">图1<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">、Fe-Zn<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">状态图<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"> <p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌钢焊接时，坡口表面及边缘处的锌层，在电弧热作用下，产生氧化、熔化、蒸发以至挥发出白色烟尘和蒸汽，极易引起焊缝气孔。<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">由于氧化而形成的ZnO<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">，其熔点较高，约<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="1800" unitname="°C">1800°C</chmetcnv><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">以上，若在焊接过程中参数偏小，将引起ZnO<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">夹渣，同时。由于Zn<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">成为脱氧剂。产生FeO-MnO<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">或FeO-MnO-SiO2<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">低熔点氧化物夹渣。<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">如果选择焊接规范不合适，操作手法不当，很容易使焊缝边缘处的镀锌层熔化以至扩大熔化区域，有可能破坏镀锌层，尤其是在拉长电弧和大幅度摆动操作情况下，增宽熔化区域，破坏镀锌层更为严重。<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">同时，由于锌的蒸发，挥发出大量的白色烟尘，对人体有刺激、伤害作用，因此，选择产生烟尘量较低的焊接方法、材料也是必须考虑的因素。

lhl · 发表于 2006-10-4 20:01

<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">二、镀锌钢的焊接特点<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌钢一般是在低碳钢外镀一层锌，镀锌层一般在20um<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">厚。锌的熔点在<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="419" unitname="°C">419°C</chmetcnv><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">，沸点<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="908" unitname="°C">908°C</chmetcnv><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">左右。在焊接中，锌熔化成液体浮在熔池表面或在焊缝根部位置。锌在铁中具有较大固溶度，锌液体会沿晶界深入浸蚀焊缝金属，低熔点锌形成“液体金属脆化”。同时，锌与铁可形成金属间脆性化合物，如Fe3Zn10<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">（δ<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">相）,FeZn10<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">（ε<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">相）等(<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">见图1)<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">。这些脆性相使焊缝金属塑性降低，在拉应力作用下而产生裂纹。如果焊接角焊缝，尤其是T<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">形接头的角焊缝最容易产生穿透裂纹。<p class="MsoNormal" align="center" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 24pt; TEXT-ALIGN: center; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"> <p class="MsoNormal" align="center" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: center; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">图1<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">、Fe-Zn<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">状态图<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"> <p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌钢焊接时，坡口表面及边缘处的锌层，在电弧热作用下，产生氧化、熔化、蒸发以至挥发出白色烟尘和蒸汽，极易引起焊缝气孔。<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">由于氧化而形成的ZnO<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">，其熔点较高，约<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="1800" unitname="°C">1800°C</chmetcnv><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">以上，若在焊接过程中参数偏小，将引起ZnO<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">夹渣，同时。由于Zn<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">成为脱氧剂。产生FeO-MnO<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">或FeO-MnO-SiO2<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">低熔点氧化物夹渣。<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">如果选择焊接规范不合适，操作手法不当，很容易使焊缝边缘处的镀锌层熔化以至扩大熔化区域，有可能破坏镀锌层，尤其是在拉长电弧和大幅度摆动操作情况下，增宽熔化区域，破坏镀锌层更为严重。<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 19.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 1.9gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">同时，由于锌的蒸发，挥发出大量的白色烟尘，对人体有刺激、伤害作用，因此，选择产生烟尘量较低的焊接方法、材料也是必须考虑的因素。

lhl · 发表于 2006-10-4 20:02

<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">三、城市燃气应用对镀锌管焊接的要求Cjj94-2003<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">《城镇燃气室内工程施工及验收规范》第<chsdate wst="on" isrocdate="False" islunardate="False" day="30" month="12" year="1899">1.0.3</chsdate><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">条规定“焊接人员应持有上岗资格证”；第2.2.5<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">条第四款规定“焊缝外观质量应符合GB50236-98<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">中表11.3.2<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">中的III<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">级焊缝标准”，第5<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">款规定“在主管道上开孔接支管时，开孔边缘距管道对接焊缝不应小于<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="100" unitname="mm">100mm</chmetcnv>,<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">当小于<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="100" unitname="mm">100mm</chmetcnv><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">时，对接焊缝应进行射线探伤”。根据GB50236-98<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">表11.3.2<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">对未焊透的要求“不加垫单面焊允许值≦0.15δ,且<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">≦<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue=".15" unitname="mm">0.15mm</chmetcnv>
缺陷总长在6δ焊缝长度内不超过δ<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">”及Cjj94-2003<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">中射线探伤要求，确定镀锌管对接焊缝应采用单面焊双面成形工艺。同时，由于单面焊双面成形工艺对焊工素质的要求较高，应选用锅炉压力容器压力管道焊工，并具有相应的焊工操作项目。由于规范未提出探伤比例，应严格要求焊工按焊接工艺确定的坡口组对，严格按工艺参数施焊，当有怀疑的时候应采用增加探伤要求或切取断面观察等验证手段。<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">三、焊接工艺的选择   <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌钢的焊接方法较多，一般在镀锌钢结构中常用气焊、手工电弧焊、CO2<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">气体保护焊、埋弧自动焊、钨极氩弧焊等方法。<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">气焊过去常用于镀锌管的焊接，由于气焊热输入不集中，容易产生缺陷，焊缝机械性能差等缺点，目前在安装行业基本淘汰。气焊对镀锌层破坏较大。CO2<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">气体保护焊对镀锌钢的焊接性能良好，当采用合适的焊接规范和匹配的保护气体、焊接材料时，可获得优质的焊接接头。该方法在工程实践中较少采用。<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">钨极氩弧焊电弧能量集中，对镀锌层的破坏较少，并且较易形成良好的单面焊双面成形接头，是值得采用的一种焊接方法，但焊接速度、较慢、成本较贵。

lhl · 发表于 2006-10-4 20:02

<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">手工电弧焊是目前管道安装中采用最为普遍的一种焊接方法。在正确权责焊条情况下，如J421<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">、J422<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">、J423<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">等氧化钛型和钛钙型焊条施焊时，由于这些焊条药皮中含有大量的金红石和钛铁矿，焊条的熔化率较大，相对增加了熔化速度。如果在不摆动条件下，只是能破坏熔池前沿等镀锌层，一般不至于扩大熔化区域，可减少锌液体对焊缝金属的渗透；在采用正确的操作方法和焊接材料的情况下，可得到接头机械性能较好，并无缺陷的焊接质量。<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">根据目前施工队伍的现实情况，由于手工电弧焊相对于钨极氩弧焊价格便宜、速度快，在具备操作熟练的焊工情况下，确定了采用手工电弧焊工艺。<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">四、焊接工艺控制<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌钢的焊前准备与一般的低碳钢是相同的，需要注意的是要认真处理好坡口尺寸和附近的镀锌层。为了焊透，坡口尺寸要适当，一般60~65°<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">，要留有一定的间隙，一般为1.5~<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="2.5" unitname="mm">2.5mm</chmetcnv>;<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">为了减少锌对焊缝的渗透，在焊之前，可将坡口内的镀锌层清除以后再焊。在实际监理工作中，采用了集中打坡口，不留钝边工艺进行集中控制，两层焊接工艺，减少了未焊透的可能性。<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">焊条应根据镀锌管的基体材质选用，一般低碳钢由于考虑易操作性，选用J422<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">较为普遍。<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">焊接手法：在焊多层焊的第一层焊缝时，尽量使锌层熔化并使之汽化、蒸发而逸出焊缝，可大大减少液体锌留在焊缝中。在焊角焊缝时，同样在第一层尽量使锌层熔化并使之汽化、蒸发而逸出焊缝，其方法是先将焊条端部向前移出约5~<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="7" unitname="mm">7mm</chmetcnv><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">左右，当使锌层熔化后再回到原来位置继续向前施焊。再横焊和立焊时，如选用短渣焊条如J427<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">，咬边倾向会很小；如果采用前后往返运条技术，更可以得到无缺陷的焊接质量。

lhl · 发表于 2006-10-4 20:03

<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌管（10#<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">钢基体）对接Φ57x3.5x100<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">，如下图 <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">焊接参数J422 φ2.5 <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">电流90~<chmetcnv wst="on" tcsc="0" numbertype="1" negative="False" hasspace="False" sourcevalue="100" unitname="a">100A</chmetcnv>,<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">电压22~24V<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">五、焊接质量保证措施      <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">从人、材、机、法、环五个方面进行控制1、          <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">人的因素是燃气镀锌管施焊的控制重点。由于缺乏必要的焊后控制手段，极易偷工减料，影响质量；同时镀锌管的焊接特殊性使得不容易保证焊接质量。因此，在工程开始前，就应该选择技术熟练、最好持有相应锅炉压力容器或相当得焊工证的焊工，进行必要的技术培训、交底，参照锅炉压力容器焊工考试规则进行现场焊工考核认可后，给予进入现场施焊的许可。并不得随意更换，保证施焊该管道焊工人员相对稳定。2、          <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">焊材的控制：保证采购的是正规渠道的焊材，有质保书、合格证，符合工艺要求；焊材的验收、领发料手续要正规齐全，焊条头回收控制严格，以保证流向、用量；焊材要严格按工艺烘烤，并一次发放不超过半天用量。3、          <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">焊机；焊机是施焊的机具，必须保证性能可靠、符合工艺需要；焊机必须有检定合格的电流、电压表，以保证焊接工艺的正确实施。焊接电缆不能过长，较长时要调整焊接参数。4、          <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">焊接工艺方法：保证镀锌管特殊操作方法的严格实施，按焊接工艺进行焊前坡口检查，施焊工艺参数、操作手法控制，焊后外观质量检查，必要时增加焊后无损检测。控制焊接层次、每道口的焊材用量。
<span lang="EN-US" style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: "Times New Roman"; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">5、<span lang="EN-US" style="FONT-SIZE: 7pt; COLOR: black; FONT-FAMILY: "Times New Roman"; mso-fareast-font-family: "Times New Roman"; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">          <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">焊接环境控制：保证施焊时的温度、湿度、风速符合工艺要求。无条件时不得施焊。

lhl · 发表于 2006-10-4 20:03

<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">六、结论：<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 27.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 2.66gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">镀锌钢管焊接已显示具有很大的优越性，在实际应用中，由于天然气的低腐蚀性，在外部接头处适当油漆防护（如富锌底漆<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">）下，能保证使用多年而不发生泄露，对楼栋管的安装提供了极大的灵活性和可能性，而丝接具有很大的危险性。手工电弧焊是目前镀锌管安装中适宜的焊接方法之一，抓住人、材、机、法、环等要素进行控制，得到优质的焊接接头，是保证日后运行安全的关键。<p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 27.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 2.66gd; tab-stops: 0cm 9.0pt;"> <p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 27.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 2.66gd; tab-stops: 0cm 9.0pt;"> <p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 27.95pt; TEXT-INDENT: 28pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: 2.0; mso-para-margin-left: 2.66gd; tab-stops: 0cm 9.0pt;"><span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">参考文献1、          <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">顾钰熹
<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">《特种工程材料焊接》，辽宁科学出版社，1998.82、          <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">中国建设监理协会
<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">《建设工程质量控制》，中国建筑工业出版社，2003<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">年1<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">月                                        <p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt 97.95pt; TEXT-INDENT: -42pt; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-char-indent-count: -3.0; mso-para-margin-left: 5.33gd; tab-stops: 0cm 9.0pt;">3<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">、  <span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">曾继炎、张同、丁晓敏
<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">《气源转换对燃气输配管网的影响及其对策》，城市公用事业， 1996<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">年第02<span style="FONT-SIZE: 14pt; COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-font-kerning: 0pt; mso-bidi-font-family: 宋体;">期

dxsdxs · 发表于 2006-10-5 11:07

当然可以焊接，不管焊接还是丝接，接头处镀锌层都是要破坏掉的，由于镀锌管一般是Q235或者20#，所以焊接工艺什么的不是问题，但是由于锌在焊接过程中容易飞溅，所以最好提前把接头处镀锌层打磨掉，至于防腐，除锈后刷防腐漆就行了，效果一样好，青岛石化厂催化车间的仪表风管道最后都给焊接上了，原因是检修中一不小心就会把丝接的管道弄漏了，还是焊接比较结实，但焊接难免内部出现杂质，这才是关键，因为杂质会把用风的仪表件打坏，所以投用前一定要吹扫干净。至于依据，设计说明上有几条，但没有强制规范支持！

sichuanhcl · 发表于 2006-10-5 16:50

打磨去掉焊接端镀锌层，焊后外表刷油漆。

jly518 · 发表于 2006-10-8 17:00

监理的依据是施工规范，但只要业主或设计同意，也可采用焊接。

dataa · 发表于 2006-10-11 18:34

去年的帖子都被顶上来了，强！！ 好像是有镀锌焊接钢管的，不过没有用过，可以网上查查，直接给厂家打电话，呵呵！

秀美林紫 · 发表于 2006-10-11 19:04

可以焊接,焊接完毕,在放到电镀槽中重新镀锌即可.我们在做海上平台施工时,就是采用的此办法,实践证明是可行的,并且规范也没有规定不可用呀

cshncn · 发表于 2006-11-6 20:28

可以焊接,焊后要采取一定的措施,但寿命会有一定的影响