Effect of tungsten on microstructure and properties of high chromium cast iron

In this study, effect of tungsten on microstructure and properties of high chromium cast iron was investigated. The experimental results indicated that tungsten distributed uniformly in the matrix and carbides. W carbides are composed of WC1−x, W6C2.54 and CW3 and W2C. With the increase of tungsten content, bulk hardness and matrix microhardness both increased gradually and reached the peak at 62.62HRC and 913HV, respectively. All of the tungsten-containing alloys performed better than tungsten-free alloys in impact tests and alloys containing 1.03 wt% W showed the highest impact toughness at 8.23 J cm−2. Tungsten considerably improved the performance of high chromium cast iron on wear resistance and alloys containing 1.03 wt% W increased 205% compared to tungsten-free alloys. Therefore, tungsten can be used as an alloying element to increase the hardness and wear resistance without scarifying impact toughness in high chromium cast iron. Alloys containing 1.03 wt% tungsten showed the optimum properties.