Abstract：Gleeble simulation and multi-pass gas metal arc welding (GMAW) method were employed to investigate the effect of heat input on microstructure and impact property of heat affect zone (HAZ) of EQ47. Coarse grained HAZ (CGHAZ) simulation results show that: with t8/5≤6s(17kJ/cm) the CGHAZ composed of a lath martensite (LM) microstructure shows an impact toughness >200J at -40℃; with t8/5 13s(25kJ/cm), formation of upper bainite (UB) are found and the impact toughness decreased to 100J at -40℃; with increasing t8/5 to 20s(30kJ/cm), coarsening of UB occurred, which results in deterioration of impact toughness to <30J at -40℃. Inter-critically CGHAZ (ICCGHAZ) simulation results show that: formation of M-A constituents along the grain boundary deteriorated impact property, and ICCGHAZ impact toughness at -40℃ decreased from 100J at t8/5 of 6s to 37J and 21J at t8/5 of 13s and 20s, respectively. GMAW results show that the impact property of CGHAZ decreased from 134-215J to 39-95J with increased heat input from 17 to 25kJ/cm, which correspond well with simulation results. It is found from both simulation and GMAW results that, the welding heat input should be controlled ≤17kJ/cm to achieve satisfactory HAZ impact toughness.
潘鑫，张宇，李小宝，鲍丙辉. 热输入对海工钢板EQ47焊接热影响区组织与冲击性能的影响[J]. 钢铁, 2013, 48(6): 80-84.
PAN Xin,ZHANG Yu,LI Xiao-bao,BAO Bing-hui. Effect of Heat Input on Microstructure and Impact Property of HAZ of Offshore Steel Plate EQ47. Iron and Steel, 2013, 48(6): 80-84.
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2013, Vol. 48 
