薄规格380 MPa级轮辋钢焊接组织与性能研究
|
摘要
采用光学显微镜、扫描电镜、维氏硬度计、万能试验机等设备对不同闪光电流密度、闪光电压条件下380CL车轮钢闪光对焊接头的显微组织和力学性能进行了研究,结果表明:380CL车轮钢闪光对焊接头可划分为界面区、粗晶区、重结晶区、部分重结晶区四个部分;不同的闪光电流和闪光电压,焊接接头的各个区域表现出具有较大差异的显微组织,热输入量越大导致晶粒尺寸越粗大;焊缝熔合线处的组织包括块状铁素体+魏氏体+渗碳体,组织尺寸较粗大;闪光电压升高,焊缝处魏氏体组织和渗碳体增多,焊缝处的硬度峰值较高,硬度下降趋势减缓,塑韧性降低;当380CL级车轮钢闪光对焊熔合线结晶良好、无焊接缺陷时,焊接接头峰值硬度即使较母材高16.67%～43.84%、出现马鞍点,焊接接头拉伸及弯曲性能良好,熔合线处未出现裂纹和断裂。
The microstructure and corresponding mechanical properties of 380CL steel welded joints after flash butt welding under different flash current density and flash voltage were studied by metallographic microscope, scanning electron microscope, Vickers hardness tester and electro-mechanical universal testing machine etc. The results show that the welded joints can be divided into four parts: interface zone, coarse grain zone, recrystallized zone, and partially recrystallized zone. Due to the different flash currents and flash voltages, different areas of the solder joint show greatly varied microstructure details. The main mechanism is that the larger the heat input, the coarser the grain size. The microstructure of the weld fusion line mainly includes massive ferrite,widmanstatten, and cementite. The the grain size is coarse. As it gradually moves away from the fusion line, the microstructure gradually converges with the base metal. The higher the flash voltage, the wider the weld heat affected zone and the higher the peak hardness exhibited. When the peak hardness of the 380CL flash butt joint was 16.67%～43.84% higher than that of the base metal,no cracks or break were observed at the fusion line during the tensile and bending tests. The main reason for having these excellent properties is that the flash butt weld fusion line crystallizes well without significant weld defects.
The microstructure and corresponding mechanical properties of 380CL steel welded joints after flash butt welding under different flash current density and flash voltage were studied by metallographic microscope, scanning electron microscope, Vickers hardness tester and electro-mechanical universal testing machine etc. The results show that the welded joints can be divided into four parts: interface zone, coarse grain zone, recrystallized zone, and partially recrystallized zone. Due to the different flash currents and flash voltages, different areas of the solder joint show greatly varied microstructure details. The main mechanism is that the larger the heat input, the coarser the grain size. The microstructure of the weld fusion line mainly includes massive ferrite,widmanstatten, and cementite. The the grain size is coarse. As it gradually moves away from the fusion line, the microstructure gradually converges with the base metal. The higher the flash voltage, the wider the weld heat affected zone and the higher the peak hardness exhibited. When the peak hardness of the 380CL flash butt joint was 16.67%～43.84% higher than that of the base metal,no cracks or break were observed at the fusion line during the tensile and bending tests. The main reason for having these excellent properties is that the flash butt weld fusion line crystallizes well without significant weld defects.
引文
[1]周磊磊. 380CL钢闪光对焊接头组织及冲击性能的研究[J].热加工工艺. 2017,46(17):210-212.
[2]李敏. 380CL钢制轮辋焊缝开裂分析[J].宽厚板,2013,19(4):28-30.
[3]孙权智.高强钢闪光对焊接头的组织及力学性能研究[D].吉林,吉林大学,2014.
[4]张洪博,谭峰亮,陈志国.闪光留量对510 MPa级车轮钢闪光对焊接头组织与性能的影响[J].材料研究学报,2017,31(2):152-160.
[5]艾海忠.进口钢轨闪光焊机监控系统改造及焊接工艺研究[D].成都,西南交通大学,2008.
[6]戴晓纲.钢轨闪光焊质量预测及工艺研究[D].成都,西南交通大学,2004.
[7]河北工业大学.闪光对焊位置伺服系统控制装:CN200910069487.8[P]. 2009-12-02.
[8]王治平,王克争,何方殿.闪光焊工艺与设备的发展[J].焊接学报,2000,21(3):93-97.
[9]惠亚军.闪光对焊焊接380CL钢轮辋焊缝开裂原因分析[J].机械工程材料,2016,40(10):100-103+107.
[10]黄东男. 380 MPa级车轮钢闪光对焊接头组织性能与失效机制[J].热加工工艺,2015,44(3):183-186.
[2]李敏. 380CL钢制轮辋焊缝开裂分析[J].宽厚板,2013,19(4):28-30.
[3]孙权智.高强钢闪光对焊接头的组织及力学性能研究[D].吉林,吉林大学,2014.
[4]张洪博,谭峰亮,陈志国.闪光留量对510 MPa级车轮钢闪光对焊接头组织与性能的影响[J].材料研究学报,2017,31(2):152-160.
[5]艾海忠.进口钢轨闪光焊机监控系统改造及焊接工艺研究[D].成都,西南交通大学,2008.
[6]戴晓纲.钢轨闪光焊质量预测及工艺研究[D].成都,西南交通大学,2004.
[7]河北工业大学.闪光对焊位置伺服系统控制装:CN200910069487.8[P]. 2009-12-02.
[8]王治平,王克争,何方殿.闪光焊工艺与设备的发展[J].焊接学报,2000,21(3):93-97.
[9]惠亚军.闪光对焊焊接380CL钢轮辋焊缝开裂原因分析[J].机械工程材料,2016,40(10):100-103+107.
[10]黄东男. 380 MPa级车轮钢闪光对焊接头组织性能与失效机制[J].热加工工艺,2015,44(3):183-186.