喷射成形含铌M3型高速钢的组织和耐磨性

发布时间：2018-03-26 19:02

  本文选题：高速钢　切入点：喷射成形　出处：《工程科学学报》2015年03期

【摘要】：采用喷射成形技术制备了M3型高速钢和以Nb替代V的M3型高速钢.利用扫描电镜、X射线衍射、差示扫描量热仪和金相显微镜研究了Nb对M3型高速钢组织的影响.喷射成形能有效消除宏观偏析,细化组织.以Nb代V,提高了MC型碳化物开始析出温度,大量MC相先于共晶反应析出,呈独立的近球形分布于晶界,同时其尺寸减小.由于消耗大量C,抑制了共晶反应,M2C片层数量减少且厚度变薄,其在热变形过程中更易于分解,进一步增加了组织均匀性.低温低载荷时含铌的M3型高速钢抗磨损性能显著优于M3高速钢,温度升高到500℃时磨损机制逐渐以氧化磨损为主,两合金的抗磨损性能差距减小,主要原因是大量呈弥散球形分布的含铌MC型碳化物能有效提高高速钢的磨粒磨损抗性,而其对抗氧化性能并无明显作用.
[Abstract]:M3 type high speed steel and M3 type high speed steel substituted by NB for V were prepared by spray forming technology. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to prepare M3 type high speed steel. The effect of NB on the microstructure of M3 type high speed steel was studied by differential scanning calorimetry and metallographic microscope. Spray forming can effectively eliminate macro segregation and refine microstructure. A large number of MC phases precipitated prior to eutectic reactions, distributed at grain boundaries as independent near-spherical particles, and their size decreased. Due to the consumption of a large amount of C, the decrease in the number and thickness of M2C lamellar layers in eutectic reaction was inhibited, and it was easier to decompose in the process of thermal deformation. At low temperature and low load, the wear resistance of M3 type high speed steel containing niobium is obviously better than that of M3 high speed steel. When temperature rises to 500 鈩，

本文编号：1669159