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对一种新型镍基耐蚀合金X-2#与625合金手工氩弧焊接接头进行拉伸性能和硬度的测试,并结合OM,SEM和EDS分析等手段研究了焊接接头的组织和性能.结果表明,X-2#/625异种金属焊接焊缝重熔区等轴晶组织增多,有利于提高焊缝区强度.X-2#合金一侧熔合区组织过渡良好,而625合金一侧晶界有Nb C和Laves相析出,影响材料的力学性能.热影响区在靠近重熔区附近的晶粒由于受2次热循环的影响,出现晶粒长大现象,而X-2#合金一侧热影响区的热稳定性较好.625合金母材晶粒细小导致其热影响区晶粒长大明显,从而使625合金一侧热影响区的Vickers硬度值降低.X-2#/625焊接接头在室温到700℃下的抗拉强度均低于2侧母材,焊缝区为接头最薄弱环节,断口形貌均为韧窝状的韧性断口.
Tensile properties and hardness of a new Ni-based corrosion resistant alloy X-2 # and 625 alloy TIG welded were tested, and the microstructure and properties of the welded joints were studied by means of OM, SEM and EDS analysis. The results show that the equiaxed grain structure of X-2 # / 625 dissimilar metal weld reflow zone is increased, which is beneficial to improve the weld zone strength.The microstructure of X-2 # Nb C and Laves phase precipitated, which affected the mechanical properties of the material.Diests in the heat-affected zone near the remelting zone appeared grain growth due to the influence of two thermal cycles, while the X-2 # alloy side The heat-affected zone has better thermal stability. The fine grain size of 625 alloy base causes the grain growth in the heat-affected zone to be significant, thus reducing the Vickers hardness of the heat-affected zone on the 625 alloy side.X-2 # / 625 welding The tensile strength of the joint at room temperature to 700 ℃ is lower than that of the 2-side base metal. The weld zone is the weakest point of the joint, and the fracture morphology is ductile fracture.