HQ130+QJ63高强钢焊接接头的组织与性能

Microstructures and Properties in the Welded Joint of HQ130+QJ63 High Strength Steels

采用光镜、电镜、冲击和拉伸等试验方法，对气体保护焊“低强匹配”焊材焊制的ＨＱ１３０＋ＱＪ６３高强钢焊接接头的显微组织和力学性能进行了试验研究，并采用模拟焊接热循环的方法研究了不同峰值温度和冷却时间对ＨＱ１３０钢热影响区（ＨＡＺ）组织和冲击韧性的影响。试验结果表明，受焊接热循环影响，ＨＱ１３０钢ＨＡＺ存在回火软化区，该区域软化或失强最大的部位在峰值加热温度为Ａｃ１附近。在ＨＡＺ峰值温度Ａｃ１～Ａｃ３之间存在脆性区，冲击韧性明显降低。在焊接生产中应采用多层多道焊工艺并严格限制焊接线能量，以防止或减弱ＨＡＺ软化和脆化现象。

Microstructures and mechanical properties in the welding joint zone of HQ130+QJ63 high strength steels, which was welded by “lower match” gas shielded metal arc welding (GMAW), are researched by means of metallography, TEM, impact and tensile test, etc . Effects of peak temperatures and cooling time on microstructure and impact toughness in the HAZ of HQ130 steel were studied by weld thermo simulation test. Experimental results indicated that there was a softened zone in the HAZ of HQ130 steel owing to the effect of the welding thermal cycle, and the most serious softened part was in the vicinity of A c1 temperature. There was a brittle zone, where the impact toughness was obviously lower, between A c1 and A c3 temperature of HAZ. Therefore, multi layer and multi pass welding, in which the welding heat input was strictly limited, should be applyed in the practical welding production to reduce the softness and brittleness in the HAZ of HQ130 steel.