机械振动对Cr12MoV冷作模具钢组织及力学性能的影响  

Effect of Mechanical Vibration on Microstructure and Mechanical Properties of Cr12MoV Cold Working Die Steel

作　　者：申振芳 张国赏[1] 游龙[1,2] 司岸恒 魏世忠 张小军 

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]河南省耐磨材料工程技术研究中心,河南洛阳471000

出　　处：《铸造技术》2017年第8期1932-1935,共4页Foundry Technology

基　　金：河南省教育厅科技开放合作项目资助(172106000011)

摘　　要：通过感应炉熔炼,吹氩精炼以及机械振动,制备了铸造Cr12MoV冷作模具钢试块,采用球化退火预处理+淬火+低温回火工艺对样块热处理,并测试其硬度与冲击韧度值,采用扫描电子显微镜(SEM)观察了试样的表面组织与断口形貌。研究了振动频率、时间对Cr12MoV组织与性能的影响。结果表明,随着振动频率与时间的增加,晶粒由柱状树枝晶转变为等轴树枝晶,晶粒明显细化,但是由于网状组织附着于晶界,所以冲击韧度值没有明显的提高。当振动频率为80 HZ、振动时间为10 min时,试样的洛氏硬度为57 HRC,冲击韧度Ak为6 J/cm^2,合金的综合力学性能最优,其组织为细针回火马氏体、大量弥散均匀分布的细合金碳化物和少量小块状条状碳化物,以及少量残留奥氏体。分析认为振动引起的强烈冲击和搅拌作用使金属液产生晶粒游离、增殖、从而细化了晶粒。The samples of Cr12MoV cold work die cast steel were prepared in a process of induction furnace and argon blowing refining and mechanical vibration. Through spheroidizing annealing, quenching and low tempering treatment, the hardness and impact toughness of the samples were measured. In addition, the microstructure and morphology of the sample＇s fracture was investigated using OM and SEM. The effects of vibration frequency and time on the microstucture and properties of Cr12MoV were studied. The results show that the grain is changed from columnar dendrite to equiaxed dendrite and the grain refinement is more obvious with the increase of vibration frequency and time. However, due to the net structure attached in the grain boundaries, the impact toughness is not significantly improved. When the frequency of the mechanical vibration is 80 Hz for 10 min, the Rockwell hardness of the sample is 57 HRC, the impact value is 6 J/cm2, and the comprehensive mechanical properties of the alloy are the best. The microstructure is composed of fine needle tempered martensite, a large number of dispersed fine alloy carbides, a small amount of small strip carbides and a small amount of retained austenite. The strong shock and stirring caused by vibration can make the metal liquid produce free grains and proliferate, thus refining the grains.

关 键 词：机械振动 铸造Cr12MoV冷作模具钢 吹氩精炼 组织 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]