0Cr17Ni4Cu4Nb钢中厚板光纤激光焊接工艺特性

Fiber Laser Welding Process of 0Cr17Ni4Cu4Nb Steel Plate with Medium Thickness

采用光纤激光对5.5 mm厚0Cr17Ni4Cu4Nb沉淀硬化不锈钢板进行激光焊接试验研究,研究了工艺参数对激光焊接接头表面成形、组织及力学性能的影响规律。结果表明:开I型坡口,采用单层激光自熔焊即可获得焊缝表面成形良好的接头。激光功率、焊接速度、离焦量是影响焊缝成形的主要因素,激光功率3500 W、焊接速度1.3 m/min、离焦量-2 mm的工艺参数下焊缝成形最佳。采用收弧末端功率衰减、速度保持的方式,可以有效改善弧坑处焊缝成形。焊缝组织主要为柱状晶内呈束状分布的板条马氏体,热影响区组织为尺寸不均匀的淬火马氏体,对接焊接头的抗拉强度为1187 MPa,达到母材的90.6%。

The fiber laser welding of 0Cr17Ni4Cu4Nb deposit hardening stainless steel plates with thickness of 5.5mm was carded out, and the effects of process parameters on the surface formation, microstructure and mechanical properties of laser welding joint were analyzed. The results show that for I type groove, good welded joint can be obtained by using the laser single-layer welding. The laser power, welding speed and defocusing distance are key factors for weld formation. The best weld formation is obtained when the laser power is 3500 W, welding speed is 1.3 m/min, and defocusing distance is -2 ram. The laser power attenuation and constant welding speed at the end of welding can effectively improve the weld formation in arc crater. The weld mierostructure is a bunch of lath martensite in columnar crystal, and the mierostrueture of HAZ is quenched martensite with uneven size. The tensile strength of the butt welded joint is 1187 MPa,which is 90.6% of that of the base metal.