摘要
利用光学显微镜、透射电子显微镜和力学性能测试，研究了不同淬火温度（850～1050℃）和回火温度（100～750℃）对PH13—8No钢微观组织和力学性能的影响。结果表明，经过淬火后形成的含有高密度位错的细小板条马氏体是该钢具有较高强韧性的组织基础，在500℃左右回火时，与基体共格的细小弥散分布的NiA1沉淀相是该钢出现强度峰值的主要原因。NiA1沉淀相在450℃左右回火时开始析出，高于510℃回火时因NiA1相长大而逐渐与基体失去共格关系，高于700℃回火时NiA1溶解。PH13．8Mo钢经925℃淬火和510cc回火可获得良好的综合性能。
Microstructure and mechanical properties of PH13-8Mo steel treated at different quenching and tempering temperatures were studied by means of optical microscopy, transmission electron microscopy and mechanical property test. The results show that the high strength and toughness is obtained due to the formation of fine lath martensite with high density dislocations after quenching. When tempering at about 500 ℃ , the fine and dispersive precipitated NiAI phase, which retains coherent lattice relationship with matrix is responsible for the strength peak of the steel. The coherent precipitation of NiAI phase occurs at about 450 ℃ , and gradually falls out of coherent lattice relationship with matrix when the tempering temperature is higher than 510 ℃. While the tempering temperature is higher than 700 ℃ , precipitated NiA1 phase is dissolved. The optimum comprehensive properties can be obtained for PH13-SMo steel after quenching at 925 ℃ and then tempering at 510 ℃.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第11期48-54,共7页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51164030)
