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本试验采用IPG YLS-5000型激光焊接系统,焊接舰船用高强钢907A三明治板。采用万能试验机、显微硬度仪、超景深三维数码显微镜以及扫描电镜,测定了T型焊接接头的拉脱力学性能、显微硬度、显微组织和断口形貌。结果表明,焊缝和热影响区的显微硬度均高于母材,焊缝显微硬度在330~360HV0.2之间;焊缝组织为板条马氏体,热影响区组织主要为马氏体、残余奥氏体及少量析出碳化物;T型接头断口属于兼有韧性断裂和解理断裂的综合断裂;焊接速度和离焦量一定时,焊缝宽度和深度随激光功率的提高而增大;T型搭接接头的力学性能主要取决于搭接处的焊缝宽度,在当前工艺条件下进行3道次的激光焊,能保证腹板和面板的接合强度比母材的强度大。
This test uses IPG YLS-5000 laser welding system, welding high-strength steel ship 907A sandwich board. Tensile mechanical properties, microhardness, microstructure and fracture morphology of T-shaped welded joints were measured by universal testing machine, microhardness tester, depth of field 3D digital microscope and scanning electron microscope. The results show that the microhardness of the weld and heat affected zone are higher than the base metal, the microhardness of the weld is between 330 and 360HV0.2; the microstructure of the weld is lath martensite; the heat affected zone is mainly composed of horse Retained austenite and a small amount of precipitated carbide. The T-joint fracture belongs to the comprehensive fracture with both ductile fracture and cleavage fracture. When the welding speed and defocus amount are certain, the width and depth of the weld increase with the increase of laser power The mechanical properties of the T-lap joints are mainly determined by the width of the welding seam at the lap joint. The laser welding of 3 passes under the current technological conditions can ensure that the joint strength between the web and the panel is greater than the strength of the base metal.