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

摘要

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％,KAV 40 J,HB硬度值234.