Heat treatment of wear-resistant cast iron at high and low temperatures

• Main Authors: Filippov, M. A., Sharapova, V. A., Shveykin, V. P., Nikiforova, S. M., Plotnikov, G. N., Michurov, N. S.
• Format: Conference Proceeding
• Language: English
• Subjects: Abrasive wear; Carbides; Cast iron; Chromium; Cold treatment; Cooling; Electron probe microanalysis; Heat treatment; High temperature; Low temperature; Low temperature resistance; Martensite; Microstructure; Quenching; Retained austenite; Wear resistance
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0037190

Electron probe microanalysis and X-ray diffraction analysis show that the maximum abrasive wear resistance of the 260Kh16M2 and 250Kh25MFT chromium cast irons with different types of carbides, Cr7C3 and Cr23C6, is provided by a metal base consisting of metastable retained austenite and martensite. This microstructure of the cast iron matrix before testing is created by high-temperature quenching with heating to temperatures of 1125-1170 °C and cooling in oil or in air. During operation, austenite on the working surface turns into dispersed martensite as a result of exposure to abrasive particles. Martensite, together with carbides, gives a high level of hardening and operability of the secondary microstructure of cast irons. An additional reserve of increasing the abrasive wear resistance of chromium cast irons by 20% consists in cold treatment after high-temperature quenching. The latter increases the content of cooling-induced carbon martensite before wear resistance testing and forms new portions of strain-induced martensite during testing.