Effect of Controlled Cooling After Hot Rolling on Mechanical Properties of Hot Rolled TRIP Steel

A three-step cooling pattern on the runout table (ROT) was conducted for the hot rolled TRIP steel. Microstructural evolution during thermomechanical controlled processing (TMCP) was investigated. Processing condition of controlled cooling on a ROT in the laboratory rolling mill was discussed. The results indicated that the micro-structure containing polygonal ferrite, granular bainite and a significant amount of the stable retained austenite can be obtained through three-step cooling on the ROT after hot rolling. TMCP led to ferrite grain refinement. Controlled cooling, after hot rolling resulted in the stability of the remaining austenite and a satisfactory TRIP effect. Excellent mechanical properties were obtained through TMCP for the hot rolled TRIP steel.