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镀锌管用什么焊接方法?

来源:http://www.jnxxjm.com

【 发布于:2019-08-12 15:27:18 】


  由于氧化而形成的ZnO,其熔点较高,约1800°C以上,若在焊接过程中参数偏小,将引起ZnO夹渣,同时由于Zn成为脱氧剂产生FeO-MnO或FeO-MnO-SiO2低熔点氧化物夹渣。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。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。

  The melting point of zinc oxide formed by oxidation is higher than 1800 C. If the welding parameters are small, the inclusion of zinc oxide will occur. At the same time, the inclusion of low melting point oxides such as FeO-MnO or FeO-MnO-SiO 2 will occur because zinc becomes a deoxidant. If the welding specification is not suitable and the operation method is not appropriate, it is easy to melt the galvanized layer at the edge of the weld and even expand the melting area, which may destroy the galvanized layer, especially in the case of elongated arc and large swing operation, widening the melting area and destroying the galvanized layer more seriously. At the same time, due to the evaporation of zinc, a large amount of white smoke and dust is volatilized, which has stimulating and harmful effects on human body. Therefore, the selection of welding methods and materials with low smoke and dust content must also be considered.

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  镀锌管的焊接方法:

  Welding method of galvanized pipe:

  一般在镀锌钢结构中常用气焊、手工电弧焊、CO2气体保护焊、埋弧自动焊、钨极氩弧焊等方法。

  Gas welding, manual arc welding, CO2 gas shielded welding, submerged arc automatic welding and tungsten argon arc welding are commonly used in galvanized steel structures.

  气焊:

  Gas welding:

  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。

  In the past, it was often used to weld galvanized pipes. Because the heat input of gas welding was not centralized, it was easy to produce defects, and the mechanical properties of welds were poor, so it was basically eliminated in the installation industry. Gas welding has great damage to galvanized coating.

  CO2气体保护焊:

  CO2 gas shielded welding:

  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。

  The welding performance of galvanized steel is good. When appropriate welding specifications and matching protective gases and welding materials are adopted, high quality welding joints can be obtained. This method is seldom used in engineering practice.

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  钨极氩弧焊电弧:

  Tungsten Arc Welding Arc:

  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。

  Energy concentration, less damage to galvanized layer, and easy to form a good one-sided welded double-sided formed joint, is a welding method worth adopting, but the welding speed is slow and the cost is expensive.

  手工电弧焊:

  Manual arc welding:

  是目前管道安装中采用最为普遍的一种焊接方法。在正确选择焊条情况下,如J421、J422、J423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。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,采用手工电弧焊工艺。

  At present, pipeline installation is the most common welding method. In the case of correct selection of electrodes, such as J421, J422, J423 and other titanium oxide and titanium-calcium electrodes, the melting rate of the electrodes is higher and the melting speed is relatively increased because of the large amount of rutile and ilmenite in the coating of these electrodes. If only the galvanized layer such as the front of the molten pool can be destroyed without oscillation, the melting area will not be enlarged and the penetration of zinc liquid into the weld metal will be reduced. Under the correct operation method and welding materials, the mechanical properties of the joints will be better and the welding quality without defects will be obtained. Because manual arc welding is cheaper and faster than tungsten argon arc welding, manual arc welding technology is adopted in the case of skilled welders.

  镀锌管的焊前准备:

  Pre-welding preparation of galvanized pipe:

  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°,要留有一定的间隙,一般为1.5~2.5mm;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。

  It should be noted that the groove size and the galvanized layer near the groove should be carefully handled. In order to penetrate, the groove size should be appropriate, generally 60-65 degrees, leaving a certain gap, generally 1.5-2.5 mm. In order to reduce the penetration of zinc into the weld, before welding, the galvanized layer in the groove can be removed and then welded. In practical work, centralized grooving without blunt edge is adopted to centralize control, and two-layer welding process reduces the possibility of non-penetration.

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  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较为普遍。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5~7mm左右,当使锌层熔化后再回到原来位臵继续向前施焊。焊接完毕后要及时清理焊缝,并刷涂富锌底漆,做好防腐措施。

  Welding rod should be selected according to the base material of galvanized pipe. J422 is a common choice for low carbon steel due to its easy operation. Welding manners: When welding the first layer of multi-layer welding seam, try to make the zinc layer melt and vaporize and evaporate out of the weld, which can greatly reduce the liquid zinc left in the weld. When fillet weld is welded, the zinc layer is melted in the first layer and vaporized and evaporated to escape from the weld. The method is to move the end of the welding rod forward about 5-7 mm, and then return to the original position after melting the zinc layer and continue to weld forward. After welding, the weld seam should be cleaned up in time, and zinc-rich primer should be brushed to prevent corrosion.

  焊接质量保证措施:

  Welding quality assurance measures:

  从人、材、机、法、环五个方面进行控制。

  Control from five aspects: human, material, machine, law and ring.

  ①人的因素是施焊的控制重点。因此,在施焊前,应选择技术熟练、持有焊工证的焊工,进行必要的技术培训、交底。并不得随意更换,保证施焊该管道焊工人员相对稳定。

  The human factor is the key point of welding control. Therefore, before welding, we should select skilled welders with welding license, and carry out necessary technical training and submission. It should not be replaced at will to ensure the relative stability of welders.

  ②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。

  (2) Welding material control: to ensure that the purchase of regular channels of welding materials, quality assurance, certification, in line with technological requirements; tightly control the recovery of electrode head to ensure flow direction, dosage; welding materials should be strictly baked in accordance with the process, and once issued not more than half a day of dosage.

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  ③焊机:焊机须保证性能可靠、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。

  Welder: Welder must ensure reliable performance and meet process requirements; Welder must have qualified current and voltage meters to ensure the correct implementation of welding process. Welding cable should not be too long. Welding parameters should be adjusted for a long time.

  ④焊接工艺方法:保证镀锌管特殊操作方法的严格实施,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。

  (4) Welding process methods: to ensure the strict implementation of special operation methods for galvanized pipes, to inspect the groove before welding, to control the welding process parameters and operation methods, to inspect the appearance quality after welding, and to increase the non-destructive testing after welding if necessary. Control welding level and welding material consumption per pass.

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  结论:

  Conclusion:

  热镀锌管焊接在施工中采取正确的焊接工艺,严格按照规范进行检查验收,焊接完毕后及时做好焊缝的防腐处理,在空调开式、闭式系统施作过程中具有一定的可行性,可以提高施工速度,提高管道连接的牢固性。所以,在施工条件允许下,在做好相关防护、防腐措施的前提下,热镀锌管采取焊接连接是对整体质量最好的连接方式。

  Correct welding process is adopted in the construction of hot-dip galvanized pipe, inspection and acceptance are carried out strictly in accordance with the specifications, and anticorrosion treatment of weld seam is done in time after the completion of welding. It has certain feasibility in the operation of air-conditioned open and closed systems, which can improve the construction speed and the firmness of pipeline connection. Therefore, under the permissible construction conditions, on the premise of doing well the relevant protective and anti-corrosion measures, the welding connection of hot-dip galvanized pipes is the best way to connect the overall quality.

  本文的精彩内容由济南镀锌管提供知识提供,更多的内容您可以点击进入:http://www.jnxxjm.com

  The highlights of this article are provided by Jinan Galvanized Pipe. For more information, you can click on http://www.jnxjm.com.



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