Влияние высоко- и низкотемпературной термообработки на структуру и абразивную износостойкость чугунов типа «Нихард»

Metallographic, micro-X-ray spectral, and X-ray diffraction analyses have shown that an increase in the heating temperature for quenching nihard chromium-nickel cast iron from 900 to 1150 °C leads to the preservation of its high abrasive wear resistance, despite a decrease in the initial hardness before the test from 60 to 35 HRC due to the fact that the phase composition of the metal base before the wear test changes during quenching from medium-carbon martensite with secondary cementite to a residual metastable austenite, which helps to increase the crack resistance of cast iron. In the process of wear testing or operation, austenite on the working surface, as a result of the impact of abrasive particles, turns into dispersed friction martensite, which, together with a part of cementite, provides a high level of hardening and operability of the secondary microstructure of cast iron.