Influence of Second Welding Thermal Cycle on Reheat Cracking Sensitivity of CGHAZ in T23 Steel
WANG Tiantian1, XU Mengjia2, XU Jijin1, YU Chun1, LU Hao1
1 School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240; 2 School of Mechanical Engineering, Shanghai Dianji University, Shanghai 201306
Abstract: The coarse-grained heat-affected zone (CGHAZ) and reheat coarse-grained heat-affected zone (reheat CGHAZ) experienced different second thermal cycle of T23 steel were produced by a Gleeble-3500 thermo-mechanical simulator, and then strain to fracture (STF) tests were carried out. Results showed that CGHAZ experienced thermal cycle of 1 350 ℃ or 780 ℃ still had coarse grain, straight grain boundary configuration and high reheat cracking sensitivity, with a reduction of area of lower than 5%. CGHAZ experienced thermal cycle of 880 ℃, 950 ℃ or 1 100 ℃ had smaller grain size, zigzag grain boundary and low reheat crac-king sensitivity, and the reductions of area were 24.67%, 16.6% and 7.24% respectively. Controlling the peak temperature of the second welding thermal cycle to the range of Ac1-Ac3 can reduce reheat cracking sensitivity.
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2017, Vol. 31 
