Medium carbon steel on-line balling rolling tech.

Abstract

The present invention discloses on-line medium carbon steel nodularizing and rolling process. The process includes low temperature finish rolling at 680-850 deg.c and accumulated cross section deformation of 50 %-80 %, controlled cooling after rolling at 3-15 deg.c / s to 660-720 deg.c, isothermal course, and naturally cooling to room temperature. The said technological scheme results in metallographic structure of the rolled piece with high ferrite component, less pearlite component, small and dispersed pearlite and granular cementite, lowered strength and hardness, raised plasticity and excellent cold machining performance.

Description

technical field

[0001] The invention relates to a metallurgical process, more specifically, the invention relates to an online spheroidizing rolling process of medium carbon steel. Background technique

[0002] Special steel occupies a very important position in the whole steel product and is an important raw material for cold processing. Special steel produced according to the traditional metallurgical production process, such as cold heading steel, bearing steel, gear steel, spring steel, alloy structural steel and carbon structural steel, etc., in order to have good cold working performance, the material is required to have low deformation resistance And excellent plasticity, therefore, the carbide (ie cementite) in the steel microstructure is required to be spherical. For this reason, spheroidizing annealing is generally performed before cold working. This annealing treatment often takes a long period, consumes a lot of energy and resources, and pollutes the environment...

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