焊接热循环对含铜时效钢热影响区组织与性能的影响  

Effect of Welding Thermal Cycle on Microstructure and Properties of Heat Affected Zone of Copper-bearing Aging Steel

作　　者：徐魁龙[1] 柴锋[1] 苏航[1] 

机构地区：[1]钢铁研究总院工程用钢所,北京100081

出　　处：《热加工工艺》2013年第19期40-43,共4页Hot Working Technology

摘　　要：采用焊接热模拟与实际焊接相结合的方法研究了焊接热循环对含铜时效钢焊接热影响区(HAZ)组织与性能的影响规律。结果表明,相同条件下模拟焊接粗晶区的低温韧性最低,硬度最高。随着t8/5的增大,粗晶区组织中板条状贝氏体数量减少,粒状贝氏体数量逐渐增多,尺寸增大,低温韧性显著降低。模拟焊接细晶区、两相区低温韧性较高,冷却速度较慢(t8/5=100 s)时其低温冲击功仍不低于200 J,维氏硬度不低于母材,表现出良好的强韧性匹配。实际焊接结果进一步表明含铜时效钢HAZ具有良好的低温韧性,在-40℃下冲击功不低于175 J,HAZ的最高硬度为249 HV,最低硬度为218 HV,与母材持平,硬化软化效果不明显。该钢具有良好的焊接性能。Combining welding thermal simulation with practical welding, the effects of welding thermal cycle on the microstrucmre and properties of HAZ were investigated in copper-bearing aging steel. The results show that the low-temperature toughness of simulated CGHAZ is lowest and the hardness is highest under the same condition. When the cooling time t8/5 increases, the amount of plate strip bainite drops and the granular bainite quantity expands. The grain size of bainite coarsens. The low-temperature toughness of simulated fine-grained region and two phase region is relatively high. When cooling time t8/5 is 100s, the impact energies is more than 200J and the hardness is higher than the base metal, which presents a good match between the strength and toughness. Furtherly, the practical welding turns out that the copper-beating aging steels have good properties at low temperature toughness. In conclusion, the copper-bearing aging steels have good welding performances.

关 键 词：含铜时效钢 焊接热影响区 气体保护焊 焊接热模拟 

分 类 号：TG406[金属学及工艺—焊接]