Strength and wear resistance in relation to the austenite grain size and fine structure of the steel

Conclusions

• 1. An increase of quenching temperature followed by high-temperature tempering increases the resistance to slip; the optimal quenching temperature for steels 45 and 40 Kh are 1100°C with holding 20 min and 1000°C with holding 2 h, respectively.

• 2. An increase of quenching temperature for the steels investigated promotes an increase in the number of lattice defects, manifest in the increase of line broadening with peaks at 1100°C (holding 20 min) and 1000°C (holding 2 h).

• 3. On quenching followed by low-temperature tempering the wear decreases with increasing quenching temperature up to a certain limit. We found a correlation between the variations of line broadening, wear, and quenching temperature.

• 4. On quenching followed by high-temperature tempering the wear increases with the quenching temperature, which is due to austenite grain growth. The inherently fine-grained steel 30KhGT is an exception.