钛变质高速钢轧辊的组织和性能

Investigations on Structure and Performance of High Speed Steel Roll Modified by Titanium Additions

借助光学显微镜、扫描电镜、X射线衍射分析和能谱分析,研究了钛对含碳量大于2.0%的高速钢轧辊组织和性能的影响。高速钢轧辊中加入钛后,可与钢液中的碳在高温下生成大量的TiC质点,而TiC可以作为奥氏体和MC型碳化物的异质核心,促进MC型碳化物弥散析出,减少大块状MC型碳化物的生成。热处理后碳化物呈颗粒状和团球状分布,使高速钢轧辊的力学性能、热疲劳性能和耐磨性明显提高,尤其是冲击韧性提高39%以上,达到10.3J/cm2。

The effects of titanium element on the microstructures and mechanical properties of cast high speed steel （HSS） roll containing more than 2.0% C were researched by means of optical microscopy （OM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD） and energy spectrum analysis. After adding titanium in the HSS melt, the solutes [Ti] and [C] form TiC in the melt. TiC can act as the substrate for the heterogeneous nucleation of austenite and MC type carbide, which promotes the disperse precipitation of MC type carbide and decreases the formation of large block MC type carbide. After heating at 1 050 ℃, the carbides in cast HSS roll transform into granular or nodular distribution. The mechanical properties, thermal fatigue and wear resistance of cast HSS roll increase obviously. Especially, the impact toughness increases by more than 39% and reaches 10.3 J/cm^2.