INFLUENCE OF TEMPERING TEMPERATURE ON THE ABRASIVEWEAR OF HIGH-STRENGTH, MARTENSITIC BORON STEELHARDOX EXTREME

Abstract

The article discusses the microstructural and wear aspects of high-strength, martensitic boron steel HardoxExtreme. It is characterised by a hardness well in excess of 600 HBW and a static tensile strength Rm over2000 MPa, which provides high resistance under abrasive wear conditions. However, such high mechanicalproperties reduce the steel's ductility parameters, including impact strength, elongation and area reduction.Examples of components exposed to abrasive wear, including ploughshares, cultivator teeth, excavatorbuckets or chutes, also require satisfactory resistance to impact wear. Subjecting Hardox Extreme steel totempering treatments can enhance its performance characteristics by increasing its plastic properties whilemaintaining satisfactory mechanical indices. Therefore, it was decided to study the tribological properties ofHardox Extreme steel after stress-relieving and low-temperature tempering treatments. In the course of thework carried out, it was shown that with a reduction in hardness from 644 HBW to 508 HBW, it is possibleto achieve satisfactory wear indices. The value of the coefficient of relative abrasion resistance kb is equal to1.36 1.12, respectively, for the as-delivered condition and after tempering treatments at 250 C.