Heat treatment for steel plates,As rolled,Normalized or TMCP ?
Source:Xin Steel Industry   Date:2015/10/22

Thermo-Mechanical Control Process (TMCP),  is a  controlled rolling processes. TMCP produces fine-grained steel by a combination of chemical composition and integrated controls of manufacturing processes from slab reheating to post-rolling cooling. There are 2 variations:-

1.Thermo-Mechanical Rolling (TMR):- fine grain size are produced by rolling in the recrystallization and the non-recrystallization regions of austenite, and sometimes in the dual-phase temperature region of austenite and ferrite.

2. Accelerated Cooling (AC):- steels meeting the specified requirements are produced by promoting grain refinement and increasing the pearlite and/or bainite volume fraction through controlled cooling (accelerated cooling and air cooling) immediately after the final controlled rolling (CR) or TMR operation.

AR- stands for as rolled condition.Plate are heated above the AC3 temperature range and rolled in continuation ( either in a  single operation or multiple rolling cycles as required).Plates usually requires normalizing following rolling.Then we say AR-N.

Pleas see the schematics below, which clearly outlines different processes. TMCP steels may be produced either by TMR or AC process, both producing  the similar steels with extremely high integrity.