锻造对TiC钢结硬质合金性能的影响

Influences of forging on mechanical properties of steel bonded titanium carbide

对用粉末冶金方法制备的Fe3.0Cr3.0Mo0.4Ni33TiC钢结硬质合金进行锻造,并测定了锻造前、后合金的密度、硬度和抗弯强度,以研究锻造对该合金性能的影响。结果表明:采用锻模锻造较自由锻造能更有效地防止锻造过程中开裂现象的产生。经过锻造,合金烧结后存在的组织缺陷被部分消除,部分TiC颗粒从连接处被破碎,这种现象在边缘区域较中心区域表现更为明显,锻造后合金的密度、硬度和抗弯强度明显提高。

With the aim of improving the properties of steel-bonded titanium carbide and thereby enlarging it's application domain, the Fe-3.0Cr-3.0Mo-0.4Ni-33TiC steel bonded titanium carbide was prepared by powder metallurgy and was then forged. The influence of forging on mechanical properties of steel bonded titanium carbide was investigated by measuring the density, hardness and bending strength. The results show that the forging with model can prevent the alloy from fracturing. A part of microstructure defects through sintering was reformed and a part of junctions between TiC particles was broken after forging. This phenomenon is more apparent in margin area than in central area. The density, hardness and bending strength of the alloy acquire improved strongly after forging, for example, comparing with before forging, after die forging the porosity changes from 065% to 0.41%, the density increases from 6.47g/cm3 to 6.51g/cm3, the hardness from 50.3HRC to 64.2HRC, and the bending strength from 1320MPa to 1555MPa, respectively, provided that the diameter of the specimen be decreased from 37.2mm to 33.1mm, i.e. the contracting ratio of the specimen's diameter be reached to 11%.