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测试一种新型镍基耐蚀合金(X-2#)手工氩弧焊接接头的拉伸性能和硬度,并结合OM,SEM和EDS等技术研究焊接接头的组织和性能.结果表明,X-2#合金焊接接头焊缝区为铸态组织,熔合区从基体到焊缝金属组织过渡良好,热影响区没有晶粒明显粗化现象,母材晶粒尺寸约为65 mm,有利于接头的焊接.新合金焊缝区的Vickers硬度小于基体,但焊缝重熔区的硬度由于等轴晶数量增多而变大.合金中W和Mo等固溶强化元素及Al和Ti沉淀强化元素使X-2#合金焊接接头具有较好的高温强度及热稳定性.合金焊接接头室温与高温下的抗拉强度均低于母材,焊接系数η大于88%,焊缝区为接头最薄弱环节,拉伸断口均为韧性断口,断裂机制为正断与剪切断的混合断裂.
Tensile properties and hardness of a new type of Ni-based corrosion resistant alloy (X-2 #) TIG welded joint were tested and the microstructures and properties of the welded joint were studied by OM, SEM and EDS techniques.The results showed that X-2 # Alloy welded joint weld zone is as-cast structure, the fusion zone from the matrix to the weld metal microstructure transition well, heat affected zone without significant coarsening of the grain phenomenon, the base metal grain size of about 65 mm, is conducive to the joint welding The Vickers hardness of the new alloy weld zone is smaller than that of the matrix, but the hardness of the weld remelt zone becomes larger due to the increase of the equiaxed grain number.The solid solution strengthening elements such as W and Mo and Al and Ti precipitation strengthening elements in the alloy make X- 2 # alloy welded joint has good high temperature strength and thermal stability.The tensile strength of the alloy welded joints at room temperature and high temperature are lower than the base metal, the welding coefficient η is greater than 88%, the weld zone is the weakest link, pull Tensile fracture are ductile fracture, the fracture mechanism for the normal and shear fracture of the mixed fracture.