Study of Differences between Results from Raboratory Tests and Tests of Real Tools for Selected Cold Work Tool Steels

Abstract

The growing pressure on tool performance and durability increases demands on the materials used and on the choice of optimal heat treatment. The properties of tool steels produced by conventional and powder metallurgy (1.2379, Vanadis 23) were compared after different heat treatment modes. Cryogenic treatment was performed in several batches for 4 hours at-90°C or-196°C. Cryogenic treatment was inserted between quenching and tempering. Mechanical properties were evaluated by hardness tests and three-point bending strength and wear resistance by Pin-on-disk tests. Metallographic analysis was performed using light and electron microscopy. On the basis of the results obtained both materials were subject to selected heat treatment and experimental forming tools produced which were used in operation. During operation the wear of the tools (shape change and volume loss) was assessed. Results of the laboratory tests were then compared with operation tests.