Nb-Ti微合金化对热轧0.5~0.7Cr铲斗刀板型钢组织和性能的影响

试验0.5~0.7Cr铲斗刀板型钢（/%：0.22~0.30C,0.25~0.45Si,0.95~1.20Mn,0.006~0.009P,0.008~0.010S,0.5~0.7Cr,0.015~0.065Nb,0~0.040Ti）由50 kg真空感应炉熔炼,热轧成16 mm厚板,终轧温度850~900℃,空冷。通过光学显微镜、扫描、透射电镜和力学性能测试研究了Nb-Ti含量（0.015Nb,0.035Nb-0.010Ti,0.065Nb-0.040Ti）对热轧态铲斗刀板钢组织和力学性能的影响。结果表明,试验钢组织为F＋P,随Nb-Ti含量增加,钢板的晶粒细化,珠光体片层间距降低,（Nb,Ti）C和（Nb,Ti）（C,N）析出物增多,强度增加,0.065Nb-0.040Ti钢板的力学性能为屈服强度632 MPa,抗拉强度916 MPa,延伸率17.7%,K_（AV）40 J,HB硬度值234。