Effects of PWHT on the toughness of weld HAZ in Cu-bearing HSLA-100 steel

Cu를 함유한 HSLA-100강 용접 열 영향부의 인성에 미치는 PWHT의 영향

A study was made to examine the effects of post-weld heat treatment (PWHT) on the toughness and microstructures in the weld heat-affacted zone(HAZ) of Cu-bearing HSLA-100 steel. The Gleeble thermal/mechanical simulator was used to simulate the weld HAZ. The behavior of Cu-precipitates in HAZ is similar to that in base plate. PWHT at 55$0^{\circ}C$ shows highest hardness and lowest toughness, whereas PWHT at $650^{\circ}C$ shows reasonable toughness. Cu precipitated during agcing for increasing the strength of base metal is dissolved during single thermal cycle to 135$0^{\circ}C$ and is precipitated little on cooling and heating during subsequent weld thermal cycle. It precipitates by introducing PWHT.