STRUCTURE AND MECHANICAL PROPERTIES OF ROLLED BARS FROM STEEL 42CrMo4

The paper presents the results of evaluation of the macro and microstructure as well as mechanical properties of rolled bars made from steel 42CrMo4 from continuously cast stock. The macrostructure was examined using Baumann's method and deep etching. Based on the examination of the macro and microstructure, it was shown that discontinuities and internal defects may occur during initial plastic processing of ingots by rolling. For high degree processing, a fine-grained structure is obtained, while for large bar diameters and low degree processing, there may be variations in the grain size in the cross-section. Mechanical properties determined from the static tensile test, impact test and hardness measurements indicate a greater influence of the sampling site than of the degree of plastic processing, which may results from both the quality of ingots and the rolling conditions.