Method for controlling nitrogen content of 20CrMnTi series gear steel with high scrap ratio produced by electric furnace process

Abstract

The invention discloses a method for controlling the nitrogen content of 20CrMnTi series gear steel with a high scrap ratio produced by an electric furnace process. The steel comprises the componentsin percentage by weight: 0.17%-0.23% of C, 0.17%-0.37% of Si, 0.80%-1.10% of Mn, less than or equal to 0.030% of P, less than or equal to 0.030% of S, 1.00%-1.30% of Cr, 0.010%-0.040% of Al, 0.04%-0.10% of Ti and the balance Fe and inevitable impurities. By reasonably controlling tapping carbon and tapping temperature of an electric furnace, selecting a reasonable technology route and key parameters, optimizing the addition amount of tapping aluminum blocks and slag charge, optimizing a refining operation technology and adopting argon sealing and an overall tundish for continuous casting, thetechnical indexes such as purity, hardenability and oxygen content of the steel for a gear are guaranteed while the nitrogen content is effectively reduced, and various technical requirements of usersfor high-grade gear steel are completely met.

Description

technical field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for controlling the nitrogen content of 20CrMnTi series gear steels with high steel scrap ratio produced by an electric furnace process. Background technique

[0002] 20CrMnTi series gear steel is the most commonly used low-carbon carburizing steel in China at present, and its consumption is relatively large, accounting for more than 50% of the total consumption of domestic gear steel. Due to the high hardenability of this steel, it has a hard and wear-resistant surface and a tough core after carburizing and quenching. It has high low-temperature impact toughness, good welding performance, good processing performance, and small processing deformation. , very good fatigue resistance, good machinability after normalizing, etc., widely used in the manufacture of important parts that withstand high speed, medium or heavy loads, impact and friction in machines,...