摘要
在气雾化HK30不锈钢粉末中分别添加0、0.4%、0.8%和1.2%的Ti粉(质量分数),采用粉末注射成形法制备HK30不锈钢样品,烧结温度为1 270、1 290和1 310℃,研究Ti含量对HK30不锈钢的密度与抗拉强度和伸长率等力学性能以及尺寸稳定性的影响。结果表明,随Ti含量增加,HK30不锈钢样品的密度、抗拉强度和伸长率都降低;由于Ti优先与材质中的C结合,与Fe结合的C含量减少,提高了液相形成温度,致密化速率降低,使得样品尺寸稳定性提高且避免过烧。最佳的烧结方案及合适的Ti含量为1 290℃/6 h和0.4%Ti,在高温抗拉强度略微降低的基础上可消除样品表面过烧,并提高样品的尺寸稳定性,具有最优的综合性能:相对密度为95.7%,室温抗拉强度535 MPa,800℃下抗拉强度215 MPa,室温伸长率21.7%。
Various contents of Ti （mass fraction of 0, 0.4%, 0.8% and 1.2%） were added respectively into gas-atomized HK30 stainless steels powder, and the HK30 stainless steel preforms fabricated by MIM （Metal Injection Molding） were sintered at 1 270℃, 1 290 ℃ and 1 310 ℃, respectively. The effect of Ti content on the mechanical properties and dimensional stability of HK30 stainless steels was investigated. The density, tensile strength, elongation and dimensional stability of HK30 stainless steels with adding different contents of Ti were tested. The results show that the density, tensile strength and elongation decrease with increasing Ti content. Since Ti is priority to Fe in combining with C, it reduce the content of C that combined with Fe, and then it improve the temperature of liquid formation, and then reduce the liquid quantity in high temperature sintering and lower the densification rate, which results in the improvement of dimensional stability and avoiding over-sintering. The optimum sintering technology for HK30 is 1 290 ℃/6 h＋0.4%Ti, by this technology the over-sintering can be avoided and dimensional stability can be improved though tensile strength at 800℃ slightly decreasing. The samples have the best comprehensive properties with relative density of 95.7%, room temperature tensile strength of 535 MPa, tensile strength of 215 MPa at 800 ℃ and room temperature elongation of 21.7%.
出处
《粉末冶金材料科学与工程》
北大核心
2013年第1期45-52,共8页
Materials Science and Engineering of Powder Metallurgy
基金
国家自然科学基金资助项目(51075405)
