【摘要】 采用扫描电镜、透射电镜和洛氏硬度计等研究了一种含6%Al、1.4%C的超高碳钢(UHCS-6Al)淬火+冷处理+回火后的组织和硬度变化。结果表明:超高碳钢(UHCS-6Al)淬火+冷处理+回火后组织为马氏体组织,峰值硬度高达65.3 HRC;回火时,基体中析出了ε碳化物,析出强化作用显著,而钢中高的Al含量通过抑制ε碳化物向渗碳体转变,显著提高了ε碳化物的稳定性,使试验钢具有优良的回火抗温性能。在200~400℃之间回火时,随回火温度提高,可以保持高的硬度(63 HRC)不变,即使480℃回火2 h后硬度仍有59 HRC。更多还原

【Abstract】 Microstructure and hardness of an ultra-high carbon steel( UHCS-6 Al) containing 6 wt% Al and 1. 4 wt% C were studied after different quenching and tempering treatment by using SEM,TEM and Rockwell hardness tester. The results show that after quenching and tempering,the microstructure of the steel is martensite and its peak hardness is up to 65. 3 HRC. The ε carbide separates out in the test steel during tempering,the precipitation strengthening effect of ε carbide is of significance. The high content of Al improves the stability of εcarbides significantly by inhibiting the transformation from ε carbide to cementite,which makes the test steel have excellent tempering and temperature resistance. When tempered at 200-400 ℃,the hardness( 63 HRC) remains unchanged with the increase of tempering temperature,even after tempering at 480 ℃ for 2 h,the hardness is still 59 HRC. And the density of the test steel is reduced about 9% than that of the GCr15 steel.更多还原