【摘要】 以4605母合金粉末为原料,采用注射成形工艺,在1 320～1 380℃烧结温度下制备4605低合金钢,并采用3种不同工艺进行热处理,研究烧结温度及热处理工艺对合金钢显微组织与硬度、抗拉强度等性能的影响。结果表明:4605低合金钢的烧结密度随烧结温度升高而增大;其显微组织由板条状马氏体和多边形铁素体组成;合金钢的硬度和抗拉强度均随烧结温度升高而升高,在1 380℃下烧结的低合金钢,致密度达96.38%,抗拉强度为613 MPa;塑性随烧结温度升高先上升后下降,在1 360℃烧结的合金钢伸长率最大,达13.5%。烧结温度为1 380℃的合金钢,经过800℃保温0.5 h,油冷,然后在200℃保温2 h的热处理后,得到马氏体组织,抗拉强度和硬度最高,分别为708 MPa和78.8 HRA;烧结温度为1 360℃的合金钢,在800℃保温1 h,油冷,然后在600℃保温2 h的热处理后,得到回火索氏体组织,伸长率最大,达到18.76%。更多还原

【Abstract】 4605 low alloy steel was prepared from 4605 master alloy powder by injection molding and sintering at 1 320-1 380 ℃. The effects of sintering temperature and heat treatment process on the microstructure, hardness and tensile strength of alloy steel were studied by three different processes of heat treatment. The results show that,the sintering density of 4605 low alloy steel increases with the increase of sintering temperature, the microstructure is composed of lath martensite and polygonal ferrite, the hardness and tensile strength of alloy steel increase with the increase of sintering temperature. The optimum properties of low alloy steel are obtained after sintered at 1 380 ℃, with its density up to 96.38% and the tensile strength is 613 MPa. The plasticity increases first and then decreases with the increase of temperature. At 1 360 ℃, the elongation of the sintered sample is optimal, reaching 13.50%. The martensite structure can be obtained through heat preservation at 800 ℃ for 0.5 h, and then at 200 ℃ for 2 h after oil quenching. The tensile strength and hardness of the sample attain to optimum, that is 708 MPa and 78.8 HRA respectively. The tempered sorbite can be obtained by heat preservation at 800 ℃ for 1 h followed by heat preservation at 600 ℃ for 2 h after oil quenching. The elongation of the sample is optimal, reaching 18.76%.更多还原