難燃性マグネシウム合金MIG溶接材の耐水素脆化性

抄録

From the viewpoint of measures against global warming and environmental protection, improvement of fuel economy of transportation vehicles is required, and weight reduction of a vehicle is cited as a solution means. Currently, the high-speed railway vehicle body is predominantly made of aluminum alloys, but by substituting magnesium alloys that are lightest among the commercially available metallic materials, it is possible to reduce the weight of the railway vehicle body. In order to realize this, flame-retardant magnesium alloys with calcium addition attract attention. MIG welding with high productivity is required for practical application of the flame-retardant magnesium alloys to high-speed railway vehicle structure, but hydrogen embrittlement resistance of flame-retardant magnesium alloy MIG weld is not clear. The SSRT tensile test and the HG-SCC test are performed on two types of MIG welds of AX92 and AX41 alloys that have been developed in the ISMA project, to evaluate the hydrogen embrittlement characteristics. For comparison, the same test was performed on MIG welds of an AZ31 alloy that is widely used as a wrought magnesium alloy.