PURPOSE: To perform welding in a way as to provide excellent resistance to stress corrosion cracking in welding of a stainless steel by providing a nozzle for ejecting cooling water toward the direction opposite from welding at a specific distance backward of a welding arc and cooling quickly the weld zone at the method to avoid intrusion of water into the molten pool.
CONSTITUTION: A nozzle 12 for ejecting cooling water of which the top end faces the direction opposite from welding is provided at 20W40mm backward of a welding arc 5 and further a copper plate 10 and stainless steel wire brush or glass fiber board 11 which are bent backward to avoid intrusion of cooling water 13 into a molten pool 6 are provided. The weld zone and weld metal 7 are quickly cooled, by which the stress corrosion cracking liable to arise in stainless steel welding is prevented and the increased yield strength and improved weld zone are obtd. The harzard of the cooling water is further prevented if a base metal 8 is inclined θ.
SHIMOYAMA JINICHI
KAMEI HIROMASA
IMADA TAKEHIKO
MURASE KAZUNORI
IKEDA TAKAO
MITSUBISHI HEAVY IND LTD