| 摘要 |
PURPOSE:To put the sensitization area of base metals under residual stress of compression and prevent the occurrence of stress corrosion cracking by laminating weld metal which is difficult to sensitize despite receiving of heat cycles in the groove then executing regular welding. CONSTITUTION:When the 1st layer W1 of weld metal of good stress corrosion cracking resistance performance is laminated in the groove part of base metals M, the base metal heat-affected zone S receiving sensitization heat cycle sensitizes and residual stress is in the state of tension +. However, when the 2nd layer W2 and the 3rd layer W3 are laminated, the residual stress distribution changes in accordance with this, and the area of tensiron + moves towards the central part of the joint. Hence, after the lamination of a number of layers, the residual stress in the sensitized area of the base metals B is compression - and no stress corrosion cracking occurs. On the other hand, in the area where the residual stress at this time is tension +, no stress corrosion cracking occurs either because of the weld metal of good stress corrosion cracking resistance. |
