How to improve the quality of stainless steel welded pipes reasonably for the problems of water seepage, steam leakage and cracking in stainless steel welded pipes? According to the control of post-weld inspection, storage, lifting, and transportation of stainless steel pipes, the quality of stainless steel welded pipes is comprehensively improved.
In order to ensure that the Surface of stainless steel pipes is not destroyed and environmental pollution, the maintenance of stainless steel pipes should be upgraded in each process of manufacturing, and the key aspects are:
1. A professional storage rack is required. The storage rack should be made of wood or Surface-coated carbon steel support frame or rubber sheet to protect it from other stainless steel materials such as carbon steel. During storage, the storage location should be conducive to hoisting, and relative protection of other raw material storage areas, and need to have safety protection measures to avoid environmental pollution of liquids, avoid collision with other prefabricated components, and environmental pollution of iron-proof metal materials. And damage.
2. When lifting stainless steel pipe, special type lifting tools should be used, such as lifting slings, special type cylinder clamps, etc. It is forbidden to apply galvanized steel wire rope to prevent scratching the Surface layer; and when lifting and placing, it should be prevented from impact bumping. Touching causes scratches.
3. If Surface scratches, electric smear marks and Surface environmental pollution occur during transportation, storage and production, it must be completely eliminated, polished with an angle grinder, and then polished with polished or metallographic paper. .
According to the provisions of electric welding, the welding Surface layer is not allowed to exceed the visible cracks, the incomplete penetration defects, and the undercut and the weld bead exceeding 0.6 mm are not allowed.
The internal penetration rate of the weld is over 96%, and the concave is less than 0.6mm; the fillet weld is fully welded on the circle, and the weld angle after welding is thicker than 1.2 times the wall thickness.
There should be no problems such as water chestnuts and burrs on the corners and joints of the welding wraps.
After the first PT test after welding, after the pass, the working pressure is 0.6 to 1.6 times the pressure test.