工程机械用Q1300E超高强钢的淬火工艺

Quenching process of Q1300E ultra high strength steel for construction machinery

利用全自动拉力试验机、全自动冲击试验机、光学显微镜和扫描电镜研究不同淬火工艺下Q1300E钢板的力学性能和显微组织。结果表明,当淬火加热时间为60 min,淬火温度为840℃时,强度和低温冲击性能最好,回火态力学性能满足GB/T 28909—2012要求,屈服强度1302 MPa,抗拉强度1505 MPa,-40℃纵向和横向冲击吸收能量分别为74 J和61 J;淬火温度为870、900和930℃时,抗拉强度和低温冲击吸收能量满足GB/T 28909—2012要求,但屈服强度低于1300 MPa;淬火温度的变化对晶粒尺寸的影响较为明显,淬火温度840℃时,平均晶粒尺寸最小,为5.7μm,淬火温度930℃时,平均晶粒尺寸为15.9μm。淬火加热时间对力学性能和晶粒尺寸的影响相对较小,当淬火温度为840℃,淬火加热时间为40~80 min时,回火态力学性能满足GB/T 28909—2012要求,晶粒尺寸为4.5~6.5μm。

Mechanical properties and microstructure of Q1300E steel plate under different quenching processes were studied by means of automatic tensile testing machine,automatic impact testing machine,metallographic microscope and scanning electron microscope.The results show that when the quenching heating time is 60 min and the quenching temperature is 840℃,the strength and low-temperature impact property are the best,and the mechanical properties in tempered state meet the GB/T 28909—2012 standard requirements.The yield strength is 1302 MPa,the tensile strength is 1505 MPa,and the longitudinal and transverse impact absorbed energy at-40℃are 74 J and 61 J,respectively.When the quenching temperature is 870,900 and 930℃,the tensile strength and low-temperature impact absorbed energy meet the GB/T 28909—2012 standard requirements,but the yield strength is lower than 1300 MPa.The change of quenching temperature has obvious influence on grain size.When the quenching temperature is 840℃,the average grain size is the smallest,which is 5.7μm.When quenching temperature is 930℃,the average grain size is 15.9μm.The influence of quenching heating time on mechanical properties and grain size is relatively small.When the quenching temperature is 840℃and the quenching heating time is 40-80 min,the mechanical properties in the tempered state meet the GB/T 28909—2012 standard requirements,and the grain size is 4.5-6.5μm.