2001 Volume 87 Issue 7 Pages 486-493
This study was performed to determine the influence of nitrogen addition on HAZ cracking susceptibility in fully austenitic stainless steel SUS310. The nitrogen content varied from 0.023 to 0.325%. The HAZ cracking behavior of nitrogen-containing stainless steels were investigated using the bead-on plate welding, the Gleeble test, and the isothermal liquation test. According to the cracking test, it was found that the HAZ cracking susceptibility in the SUS310 alloy decreased with increasing the nitrogen addition. The Gleeble and the isothermal liquation test revealed that the HAZ cracking was closely related to the intergranular liquation caused by Si and P segregated at the grain boundaries, which has the much lower melting point than that of the γ-matrix. The degree of intergranular liquation in the high nitrogen containing specimen was less than that of the low nitrogen containing specimen due to the decrease of Si and P segregation at the grain boundaries, which seems to be responsible for less liquation cracking susceptibility in the high nitrogen containing specimen.
