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60Si2Cr VAT弹簧钢分别采用不同浓度PAG淬火介质和淬火油进行淬火,并在440℃和480℃的温度下进行回火处理,利用透射电镜和拉伸试验机等方法研究了该弹簧钢在不同淬火介质中淬火回火后的微观结构和力学性能的变化。结果表明,PAG淬火介质对其强度和塑性的影响显著。随着PAG浓度的增加,冷却速度降低,马氏体板条数量减少,板条宽度变大,强度和塑性呈现先增后降的趋势;冷速最快的5%PAG淬火回火后,针状的ε-碳化物未完全分解,容易在其尖端引起应力集中,使得力学性能较低;冷速最慢的油淬回火后,由于碳化物沿原奥氏体晶界和马氏体板条界析出,固溶度的下降,马氏体板条宽度的变大及数量的减少,最终也使得其强度、塑性和冲击韧性降低;只有冷速适中的13%PAG淬火后得到的综合力学性能最佳。
60Si2CrVal spring steel were quenched with different concentrations of PAG quenchant and quenching oil and tempered at 440 ℃ and 480 ℃, respectively. The effects of different quenching temperatures Microstructure and Mechanical Properties of Quenched and Tempered Medium. The results show that, PAG quenching medium on its strength and plasticity significantly. With the increase of PAG concentration, the cooling rate decreased, the number of martensite laths decreased and the width of laths increased. The strength and ductility tended to increase first and then decrease. After the fastest 5% PAG quenching and tempering, Shaped ε-carbide is not completely decomposed, it is easy to cause stress concentration at the tip, resulting in lower mechanical properties; the slowest speed of oil quenching and tempering, the carbide along the original austenite grain boundaries and martensite plate The results show that the decrease of solid solubility, the increase of martensite lath width and the decrease of the number of lamellae decrease the strength, ductility and impact toughness. Best performance.