N50不锈钢铠甲焊丝研制与焊接接头性能研究

Study on welding wire and performance of welded joint for N50 stainless steel jacket

针对核聚变CICC导体铠甲,通过设计成分以及采用真空冶炼、电渣、轧制和拉拔等工艺,研制出SGN50WG不锈钢焊丝。利用制备的SGN50WG焊丝采用氩弧焊焊接CICC铠甲用N50方圆管,并对焊接接头进行组织表征和力学性能检测。结果表明,所有焊接接头焊缝与母材结合良好,经过冷变形和导体热处理工艺后4.2 K下表现出优异的强韧性(角位置和面位置屈服强度分别为1442和1378 MPa,抗拉强度为1698和1684 MPa,延伸率为23.8和20.1%,断裂韧性高达195 MPa·m^(1/2)),有望用作CICC铠甲焊接材料。

For the CICC conductor jacket,SGN50WG stainless steel welding wire was developed through designing the composition and using processes such as vacuum melting,electroslag,rolling and drawing.This welding wire was then employed to weld N50 circle-in-square tubes for CICC jacket by TIG welding.The microstructures and mechanical properties of the welded joints were thoroughly characterized and tested.The results demonstrate that all welded joints exhibit excellent bonding between the weld metal and the base metal.These joints exhibit excellent strength and toughness at 4.2 K after cold-deformation and conductor heat-treatment with yield strengths of 1442 MPa and 1378 MPa at the corner position and plane position respectively,ultimate tensile strengths of 1698 MPa and 1684 MPa,elongations of 23.8%and 20.1%,and fracture toughness as high as 195 MPa·m^(1/2),suggesting this welding wire has promising potential as a welding material for CICC jacket.