选区激光熔化成形尺寸对304L不锈钢点蚀性能的影响

Effect of Building Dimensions by Selective Laser Melting on Pitting Properties of 304L Stainless Steel

采用选区激光熔化(SLM)技术制备304L不锈钢样品,通过改变样品的宽度和厚度使其具有不同的成形尺寸。模拟复杂结构零部件在成形过程中不同部位的尺寸和厚度的差异,研究了不同成形尺寸304L样品的显微组织和点蚀行为。结果表明:随着成形尺寸的增大点蚀坑的数量和面积随之增加。点蚀加剧的主要原因,是晶粒尺寸的增大和残余应力的累积。根据对微观组织结构和NETFABB残余应力的模拟计算结果,揭示了SLM成形尺寸-微观组织-腐蚀行为之间的关系。

The impact of building dimensions on the corrosion performance of the selective laser melting(SLMed)304L stainless steel with different thickness and width was investigated by changing the scanning track(T)and depositing layers(L).The results show that the coarsening of grain size and the accumulation of the residual stress,as well as the number of pits and the pitting area all increased with the increasing of sample size.Accordingly,the preliminary relationship between dimension design,microstructure morphology,corrosion performance and residual stress were established.