论文部分内容阅读
采用等离子填丝焊工艺对轨道车辆用2 mm厚的X2Cr Ni N18-7不锈钢薄板进行对接焊接试验,通过正交试验对焊接电流、焊接速度、送丝速度和离子气流量参数进行了优化,并对最佳工艺参数下的焊接接头质量进行了焊接工艺评定。结果表明:使用Plasmatron等离子焊机成功实现了X2Cr Ni N18-7不锈钢薄板等离子填丝对接焊,优化的焊接工艺参数为焊接电流160 A,焊接速度0.25 m/min,送丝速度3.0 m/min,离子气流量5 L/min;焊缝成形良好,背面全焊透,经X射线探伤无未焊透、未熔合和裂纹等缺陷;焊接接头的综合力学性能良好,焊接接头的抗拉强度平均值为636.57 MPa,焊接接头强度系数为92.28%;180°横向正弯试验结果显示,试样正反两面均无裂纹;当疲劳测试加载循环次数为1.0×107次时,焊接接头的疲劳极限为270 MPa。
The butt welding test of 2 mm thick stainless steel X2Cr Ni N18-7 stainless steel sheets for rail vehicles was carried out by plasma filler wire welding. The parameters of welding current, welding speed, wire feeding speed and ion flux were optimized by orthogonal test. The quality of welding joints under the best technological parameters was evaluated by welding procedure. The results show that the plasma welding butt welding of X2Cr Ni N18-7 stainless steel sheet is successfully realized by using Plasmatron plasma welding machine. The optimum welding parameters are welding current 160 A, welding speed 0.25 m / min, wire feed speed 3.0 m / min, Ion flux 5 L / min; weld formation good, full penetration of the back, X-ray flaw detection without penetration, not fusion and cracks and other defects; comprehensive mechanical properties of welded joints, the average tensile strength of welded joints 636.57 MPa and the strength coefficient of welded joints was 92.28%. The results of 180 ° transverse positive bending test showed that there was no crack on both the front and the back of the specimen. The fatigue limit of the welded joints was 270% when the fatigue test loading cycles were 1.0 × 107 cycles MPa.