Method and steel component

US10202678B2 · kind B2 · utility

Assignee

• AKTIEBOLAGET SKF · SE

Inventors

• Thore Lund · Handen, SE
• Tobias Meyer · Durham, US
• Staffan Larsson · Säter, SE
• Peter Neuman · Wardenburg, DE

Key dates

• Filing date: May 22, 2012
• Grant date: Feb 12, 2019
• Expiry date: Aug 21, 2034

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16C2360/31
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Method for heat treating a steel component (28, 36) comprising the steps of: a) carbonitriding the steel component (28, 36) at a temperature of 930-970° C., b) cooling the steel component (28, 36), d) re-heating the steel component (28, 36) to a temperature of 780-820° C. and d) quenching the steel component (28, 36). The method comprises the step of either e) performing a bainite transformation at a temperature just above the martensite formation temperature, transforming 25-99% of the austenite into bainite at the temperature and then increasing the temperature to speed up the transformation of the remaining austenite into bainite, or f) holding the steel component (28, 36) at an initial temperature (T1) above the initial martensite formation temperature (Ms), and lowering the initial temperature (T1) to a temperature (T2) that is below the initial martensite formation temperature (Ms) but above the actual martensite formation temperature during the bainite transformation.