烧结气氛对MIM316L不锈钢微观组织和性能的影响

INFLUENCE OF SINTERING ATMOSPHERE ON MICROSTRUCTURE AND PROPERTIES OF MIM316L STAINLESS STEEL

在Ar、Ar +H2 、N2 、N2 +H2 四种气氛下对MIM 31 6L不锈钢进行了烧结 ,讨论了烧结气氛对样品C、O、N含量、烧结密度、晶粒形貌和力学性能的影响。结果表明四种气氛烧结下样品C、O、N含量可控制在许可范围内。烧结气氛的露点显著影响着合金的致密化和最终力学性能 ;N2 +H2 气氛烧结下样品的抗拉强度和延伸率分别可达到 76 5MPa和 32 % ;Ar和Ar+H2 气氛烧结下样品致密化程度高 (可达理论密度的 98% ) ,孔隙细小、圆滑、分布均匀 ,晶粒尺寸大约为 5 0 μm ;样品的力学性能如下 :极限拉伸强度 6 30MPa、屈服强度 2 80MPa、延伸率5 2 %、硬度HRB 6 9 5。

Ar,Ar+H 2,N 2,N 2+H 2,were used as the sintering atmosphere for MIM316L stainless steel The influence of the sintering atmospheres on C,O,N content, sintered density,grain morphology and mechanical properties of sintered specimens were investigated The results show that C,O,N content of sintered specimens can be controlled in a permitted range The dew point of sintering atmosphere influences the densifaction and mechanical properties of alloy conspicuously The ultimate tensile strength and elongation of the specimens sintered in N 2+H 2 atmosphere was 765 MPa and 32 % respectively Using Ar and Ar+H 2 as the sintering atmosphere,the density of the sintered specimens was 98 % of the theoretical density;the pores of small spherical shape were uniformly distributed and the grain size was about 50*!μm The mechanical properties of the specimen were as follows:ultimate tensile strength 630 MPa,yield strength 280 MPa,elongation 52 %,HRB 69 5