不锈钢堆焊层上细长孔底部修复

Repair of Long Drillings in Stainless Steel Clad-Welded Layers

针对已完成精加工的不锈钢堆焊密封面上钻孔,将不锈钢堆焊层钻穿,致使与底部低合金钢相通,给耐蚀容器使用带来极大隐患的事故,介绍一种小直径孔底修复工艺,采用填充同材质金属堵,再加自动氩弧焊,使表面自熔熔深大于2 mm的密封焊工艺。该工艺能避免常规的预热,焊后热处理、密封面研磨等修复工序,极大地降低了生产成本,加快生产进度。使用该工艺完成的全部12个螺纹孔底密封焊,经液体渗透检验合格,并通过业主和第三方监造联检验收,孔内螺纹和密封面无一损伤,实现了预期的目标。

Drilling operation was performed wrongly on the final machined surfaces of the stainless steel clad-welded layer. The drillings are through the layer and into the base alloy steel, which brings considerably safety risk for the operation of anti-corrosion vessels. The paper introduces a procedure to repair the bottom of small-diameter drillings. The procedure is to weld a plug in the material same with filler metal by the means of automatic argon-ace welding technique to make the plug surface fuse over 2 mm deep to seal the base metal. This procedure does not need conventional preheating, post-weld heat treatment, and sealing surface grinding and other repair processes. So, the manufacture cost reduces significantly and the manufacture can make progress greatly. The seal welds on 12 thread drillings that are repaired with this procedure all has past PT examination successfully and are accepted by the owner and third-party inspection agency. No damage happens on the thread and sealed face in the drillings. The expected target has been reached.