The Effect of Cutting Techniques on the Structure and Properties of Low-Alloy Martensitic Steels

Abstract

The paper analyses the effect of cutting techniques on the structure and properties of low-alloy martensitic steels. Tests involved steels characterised by increased abrasive wear resistance. The test steels were provided by four steel manufacturers. The cutting process was performed using a gas torch, plasma, abrasive waterjet and a band saw. The research work included hardness measurements of plates in the pre-treatment state, the distribution of hardness in the cut zone, measurements of surface roughness after cutting as well as metallographic tests of the base material (BM) and the heat affected zone (HAZ). The cutting method significantly affected the operational properties of abrasion-resistant steels. In terms of the surface quality, the most favourable results were obtained using the plasma cutting process, which was confirmed by related measurements of surface roughness. The cutting process involving the use of gas torches and plasma led to the deterioration of the mechanical properties of the steel in the cut zone. The aforesaid result could be ascribed to the formation of the HAZ in this area, the morphology of which was similar to the HAZ formed during the welding process. The hardness measurements and metallographic tests concerning the cut zone revealed a significant decrease in steel hardness, resulting from heat-triggered structural changes.