【摘要】 为探索淬火-分配(Q-P)工艺和分级淬火-分配(S-Q-P)工艺对中高碳钢力学性能的提升作用,对两种中高碳硅锰钢分别进行淬火-回火(Q-T)、Q-P和S-Q-P工艺处理。用拉伸试验机测定抗拉强度和断后伸长率,利用XRD测定残留奥氏体体积分数用SEM分析微观组织。力学性能试验结果显示,与传统的Q-T和当前流行的Q-P工艺相比经S-Q-P处理后钢的综合力学性能显著优化。特别是当含硅量较高时,S-Q-P处理后的中高碳硅锰钢强塑积比Q-T处理后提高3倍以上。微观组织分析表明,S-Q-P处理过程中碳分配过程更加充分,其中的硅元素起到抑制贝氏体竞争反应的作用,因而中高碳硅锰钢经S-Q-P处理后表现出很好的综合力学性能。此外,Q-P工艺对中高碳硅锰钢综合力学性能的改善作用不明显,可能是由于其中发生大量竞争反应,产生贝氏体组织所致。更多还原

【Abstract】 In order to investigate the potential of Q-T and S-Q-P processes on enhancing mechanical properties of medium-high carbon steel two steels were treated by Q-T,Q-P and S-Q-P processes,respectively.The ultimate tensile strength and total elongation of the samples were obtained on a tensile testing machine.Volume fractions of retained austenite were calculated from XRD spectrum.Microstructure photographs were obtained by SEM.The results show that,compared with Q-T and Q-P processed steels,samples processed by S-Q-P show better mechanical properties.Especially,the product of strength and ductility of higher silicon steel is 3 times higher than that of lower silicon steels.Microstructure analysis indicate that carbon partitioning in S-Q-P process is more thorough.What’s more,because of the inhibiting effect of silicon on bainite transformation during partitioning process,S-Q-P processed medium-high carbon steels display much more favorable mechanical properties.In addition,the test results proves the Q-P process to be ineffective in improving mechanical properties of medium-high carbon steels,probably because much austenite transform into bainite during partitioning.更多还原