Effect of welding condition on solidification cracking behaviour in austenitic stainless steel

Abstract

The effect of welding condition on solidification cracking behaviour was investigated during the U-type hot cracking test. In order to investigate the behaviour of solidification cracking, a hightemperature ductility curve and a thermal strain curve were calculated. The high-temperature ductility curve was obtained based on a combination of the solidification initiation and completion temperatures, in addition to the critical strain, while the thermal strain curve was calculated using a finite-element model (FEM). The solidification brittleness temperature ranges (BTR) were almost constant. However, increasing the heat input suppressed cracking by reducing the slope of thermal strain due to yield strength reduction in heat-affected zone resulting in relieving a stress on weld bead, and eventually, solidification cracking was suppressed.

Back diffusion resisting solidification cracking in austenitic stainless steels

“…Other parameters were estimated values that are also used for other alloy systems. The cooling rate used in the calculation was 420°C s −1 and the temperature gradient 18°C mm −1 , taken from Lee et al [22] in gas-tungsten arc welding of 310 stainless steel. The cooling rate 420°C s −1 was measured during bead-on-plate welding of a 310 stainless steel sheet 2 mm in thickness at 5 mm s −1 welding speed, 110 A welding current, and 220 J mm −1 heat input.…”