激光熔覆修复15-5PH不锈钢的拉伸性能及组织研究

研究了激光熔覆修复15-5PH沉淀硬化不锈钢激光熔覆修复比例(25%、50%、75%、100%)对其力学性能的影响,以及熔覆修复后试样的断口形貌、金相组织、内部缺陷和显微硬度。研究结果表明,15-5PH不同比例熔覆修复试样的抗拉强度均高于基材,但塑性随着修复比例的增大而降低,在所研究的4种熔覆修复比例的试样中,25%熔覆比例时抗拉强度最高,力学性能最好。熔覆修复冶金组织致密,分为修复区、热影响区和基材区,其中热影响区的组织呈现明显的方向性,晶粒均匀性好,无粗大晶粒,表面和内部无裂纹缺陷,显微硬度从修复区向基材区整体呈上升趋势,在热影响区内出现硬度峰值。熔覆界面的结合力较基体内部的结合力弱,修复试样的断口均呈V字形。

Study on Tensile Property and Microstructure of Laser Cladding Repaired of 15-5PH Stainless Steel

The affect of cladding reparation rate (25％,50％,75％ and 100％) on mechanical property of 15-5PHprecipitation hardening stainless steel is studied.Cladding repairing samples are also used for testing fractograph,metallographic structure,internal flaws and microstructure hardness.The results show that the tensile strength under different cladding reparation rate is higher than the matrix;however its ductility decreases with the increase of cladding reparation rate.Among all the studied samples,the tensile strength and mechanical property reach the peak under 25％ cladding reparation rate sample.The metallographic structures of cladding reparation area,heat-affected zone and undamaged matrix is compact.Among them,the structure of heat-affected zone shows apparent direction,with refined grains and flawless interface and surface.The microstructure hardness rises from cladding reparation to matrix,with peak value in heat-affected zone.The adhesive force of cladding area is weaker than that of inner matrix.The results show that fractograph of samples all resemble V shape.