锰含量对中碳冷镦钢组织和性能的影响

Effect of Manganese Content on Structure and Properties of Medium-Carbon Cold-Heading Steel

分析和研究了0.75%~1.54%Mn对中碳冷镦钢Φ16 mm热轧盘条(/%:0.45C,0.22Si,0.75~1.54Mn,0.007~0.008P,0.003~0.004S)组织和性能的影响。盘条热轧的终轧温度为880℃,缓冷。结果表明,锰含量由0.75%增加到1.54%,盘条抗拉强度由661 MPa增加到821 MPa,增加了160 MPa;钢的组织中铁素体比例由49%~53%降低到9%~13%,珠光体含量显著增加,且珠光体片层间距由0.5μm降低到0.25.μm;淬透性能得到显著提高,淬透性系数由3.19 mm增加到8.81 mm。

The effect of O. 75% - 1.54% Mn on structure and properties of qbl6 mm hot-rolled coil of medium-carbon cold-heading steel （/% ： 0. 45C, 0. 22Si, 0. 75 - 1.54Mn, 0. 007 - 0. 008P, 0. 003 - 0. 004S） has been analyzed and studied. The end-rolling temperature of hot-rolling coil is 880 ℃ , slow-cooling. Results show that with increasing manga- nese in steel from O. 75% to 1.54% , the tensile strength of coil increases from 661 MPa to 821 MPa, i.e. that increases by 160 MPa; the percentage of ferrite in structure of steel decreases from 49% - 53% to 9% -13% , the pearlite content in structure increases obviously and the pearlite lamellar spacing reduces from 0. 5 μm to 0. 25 μm; and the hardenability of steel improves siificanfly, that is the hardenabilitycoefficient of steel increases from 3.19 mm to 8.81 mm.