Testing of wear properties of inserts made from semi-solid processed experimental steel

Abstract

To reduce the cost of manufacturing tools, which are commonly made from powder steels, high-alloy tool steel in the form of an ingot was cast. Conventional casting allows better use of recycled materials and an overall reduction in material production costs. This experimental steel was then processed in a semi-solid state to remove the unsuitable casting structure and to obtain the desired functional properties. In the case of tools, it is primarily a sufficient toughness and abrasion resistance. To determine the wear resistance of the experimental steel, replaceable inserts for machining tests were made. The inserts were prepared by electro-erosive machining. During testing, the geometry of the insert was optimized to achieve good chip evacuation and other cutting properties. Wear was measured using a digital microscope and at the same time, the roughness of the workpiece was measured. For comparison, a powder steel insert of the corresponding chemical composition was also produced, which has the commercial title Böhler K390 Microclean. This steel was heat-treated according to the manufacturer's recommendations. By comparing the results obtained on experimental cast steel and commercially produced powder steel, it was found that cast steel processed by semi-solid technology achieves three times lower cutting-edge wear during machining than powder steel.