Abstract: The high strength free-cutting precipitation hardening stainless steel 2Cr16Ni3Mo2CuN has excellent cutting property in annealing conditions. The Brinell hardness(HB)number of steel 2Cr16N3Mo2CuN treated by first annealing at temperature between 710 ℃ and 800 ℃ and second annealing at temperature between 570 ℃ and 620 ℃ and the mechanical properties of steel treated with 1050~1085 ℃ for 45 min oil cooling,-70 ℃ for 2 h and 150 ℃ or 170 ℃ tempering have been studied. The test results showed that HB number of steel 2Cr16Ni3Mo2CuN treated with 710~740 ℃ for 5 h + 620 ℃5 h was less than 321 and tensile strength σ_b of steel was ≥1520 MPa,δ₅≥12% and impact energy A_KU≥40  J. The steel 2Cr16Ni3Mo2CuN showed obvious secondary hardering effect and the peak temperature range of this effect was between 480 ℃ and 520℃.

Key words: Free , Cutting,High , Strength,Precipitation , Hardening , Stainless , Steel,Heat , Treatment,Mechanical Properties

摘要： 高强度易切削沉淀硬化不锈钢2Cr16Ni3Mo2CuN在退火状态下有优良的切削性能。研究了经过一级退火温度710~800℃和二级退火温度570~620℃处理后2Cr16Ni3Mo2CuN钢的布氏硬度(HB)值,以及1 050~1 085℃45 min油冷,-70℃2 h,150,170℃回火后的力学性能。试验结果表明,710~740℃5 h空冷+620℃5 h空冷处理后,2Cr16Ni3Mo2CuN钢HB值在321以下;1 050~1 085℃淬火,150~200℃回火处理后,该钢强度极限σ_b≥1 520 MPa,δ₅≥12%,冲击功A_KU≥40 J。2Cr16Ni3Mo2CuN钢具有明显的二次硬化特征,二次硬化峰温度范围为480~520℃。

关键词: 易切削, 高强度, 沉淀硬化不锈钢, 热处理, 力学性能