Welding process welding stainless steel, process equipment, ultra-pure water production equipment supply, and ultra-high purity gas supply piping system

摘要

PURPOSE:To provide the welding method capable of preventing generation and resticking of metallic fumes in the vicinity of the weld zone surface and reducing the precipitation quantity of a chromium carbine. CONSTITUTION:In the welding method where respective specified parts (weld zone) of plural stainless materials are melted and solidified and plural stainless steel members are joined together, heat gains to the weld zones are regulated to =600 joule/cm. Further, the welding speed is regulated to =20cm/min. In addition, in the stainless steel materials, the sum total of the elution quantity of Fe, Ni, Cr and Mn when objects to be welded are cleaned by the superpure water (15L/hr. flow rate, 6 hours) after welding is regulated to =0.1mug per weld length 1cm.