Wu Ju

High temperature wear characteristics of a new hot work die steel CH95

High temperature wear characteristics of a new hot work die steel CH95 doped with a small amount of rare earth (Re) and boron (B) have been investigated and compared with those of conventional die steel H11 at a series of temperatures and loads. Worn surfaces of CH95 steel and H11 steel were analyzed with a scanning electron microscope. It is found that high temperature mechanical properties of CH95 steel are much better than those of H11 steel. The oxide layer formed on the worn surface plays an important role in wear resistance at high temperature. When the load is less than 63 N, the surface oxide layer keeps integrated and the effect of load on high temperature wear is small. When the load is higher than 63 N, the supporting ability of matrix to the oxide layer decreases with the increase of load, which results in an increase of wear rate. Compared with H11 steel, the wear resistance of CH95 steel is much better and the worn surface of CH95 steel is smoother. It is easier for CH95 steel to form a compact and integrated surface oxide layer at high temperature than for H11 steel, which protects the worn surface and reduces wear.