热切割热影响区对Q345E焊接接头组织和性能的影响
Effect of Heat Affected Zone of Thermal Cutting on Microstructure and Properties of Welded Joints of Q345E
马清波1， 陈丽园2， 许鸿吉2
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作者单位：（1.齐齐哈尔轨道交通装备有限责任公司，黑龙江 齐齐哈尔161002； 2.大连交通大学 材料科学与工程学院，辽宁 大连 116028）
中文关键字：Q345E； 热切割； 热影响区； 焊接接头
英文关键字：Q345E; hot cutting; heat affected zone; welded joint
中文摘要：通过对火焰切割试样和机械加工试样焊接接头的抗裂性试验、拉伸试验、冲击试验、弯曲试验、显微硬度试验以及金相分析，研究了热切割热影响区对Q345E焊接接头组织和性能的影响。结果表明，火焰切割试样焊接接头的焊接热影响区比机械加工试样焊接接头的焊接热影响区宽，硬度低；两种焊接接头都具有良好的抗裂性能、冲击性能、拉伸和弯曲性能。组织大体相同：焊缝为先共析铁素体呈树枝状晶分布，热影响区为沿晶界析出的块状铁素体，母材为呈带状分布的铁素体+珠光体。所以，焊前直接采用火焰切割坡口的工艺可行。
英文摘要：Through the anti-cracking test, tensile tests, impact test, bending test, microhardness test and metallographic analysis of hot cutting heat affected zone, the effects of the HAZ of thermal cutting on microstructure and mechanical properties of Q345E welded joint were studied. The test results show that the flame cutting heat affected zone is wider than machining and lower in hardness. Two kinds of welded joint have good crack resistance, impact toughness, stretching and bending performance. The weld lane is eutectoid ferrite distributing in dendrites. Heat affected zone is massive ferrite along the grain boundaries, the raw material is ferrite+pearlite. So before welding, the process flame cutting groove is feasible.