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热风炉焊缝的返修要求!

2019-04-13 来源:http://www.zhongyanjixie.com 发布人:admin 浏览量:
1)焊缝的返修应由合格的焊工担任。返修工艺措施应得到焊接技术负责人的同意。压力容器上同一部位的返修次数不应超过2次。对经过2次返修仍不合格的焊缝,如再进行返修,应经制造单位技术负责人批准。返修的次数、部位和无损探伤结果等,锅炉厂应记入压力容器质量证明书中。锅炉同一位置上的返修不得超过3次。
1) The repair of the weld shall be performed by qualified welders. Repair process measures should be agreed by the person in charge of welding technology. The number of repairs to the same part of pressure vessel should not exceed 2 times. For welds that are still unqualified after two repairs, if they are repaired again, they should be approved by the technical director of the manufacturing unit. The number of repairs, locations and non-destructive testing results shall be recorded in the quality certificate of pressure vessels in the boiler plant. Boiler repairs at the same location shall not exceed three times.
2)要求焊后热处理的锅炉、压力容器,应在热处理前返修;如在热处理后返修,返修后应再做热处理。
2) Boilers and pressure vessels requiring post-weld heat treatment should be repaired before heat treatment; if they are repaired after heat treatment, heat treatment should be done after repair.
3)有抗晶间腐蚀要求的奥氏体不锈钢制压力容器,返修部位仍需保证原有要求。
3) Austenitic stainless steel pressure vessel with anti-intergranular corrosion requirement should be repaired to ensure the original requirement.
4)压力试验后,一般不应进行焊缝返修。确需返修的,返修部位必须按原要求经无损探伤检验合格。由于焊缝或接管泄漏而进行的返修,或返修深度大于1/2壁厚的压力容器,还应重新作压力试验。
热风炉生产厂家
4) Weld repair should not be carried out after pressure test. If it really needs to be repaired, the repaired parts must be qualified by non-destructive testing according to the original requirements. Pressure tests should also be re-conducted for pressure vessels whose repair depth is greater than 1/2 of the wall thickness due to leakage of welds or nozzles.
焊缝多次返修,即使是无损探伤、力学性能试验和金相检验都未发现异常,但仍然对焊接接头质量有不良的影响。首先,由于焊接次数的增加,焊缝金属中溶解的氢气向过热区扩散量必然增加,成为产生热影响区冷裂纹、延迟裂纹的隐患;其次是过热区的晶粒因多次过热而长得更大,造成组织不均匀和力学性能下降。因此焊缝返修前应先找出产生缺陷的原因,制订可行的返修方案,才能进行返修。
Repair of weld seam for many times, even though no abnormality was found in non-destructive testing, mechanical properties test and metallographic examination, still has a negative impact on the quality of welded joint. Firstly, with the increase of welding times, the amount of hydrogen dissolved in the weld metal will inevitably increase to the superheated zone, which will become the hidden danger of producing cold cracks and delayed cracks in the heat affected zone. Secondly, the grains in the superheated zone grow larger due to repeated overheating, resulting in uneven structure and decreased mechanical properties. Therefore, before repairing the weld, it is necessary to find out the causes of the defects and work out a feasible repairing plan before repairing the weld.
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