Theory and Practice of Hot Ribbed Bar Production for III,IV Class With New TMCP

New TMCP,which hot ribbed bar is produced with ultra fast cooling technology after rolling,is a creative,applicable technology.There are obviously different on production properties with heat residual quenching technique,which mainly in material's ductility promotion with the rise of strength.This is necessary and essential for earthquake-resistant ribbed bar and HRB500 ribbed bar production with 20MnSiV or 20MnSiNb.Authors have studied the 6~32mm specimens from 600 thousand ton ribbed bar in a year which tested by construction test department of province.The test contents include chemical composition analysis,metallographic analysis,mechanical properties test,welding test,mechanical connection test,rust-eaten comparison,component test and engineering application experiments and so on,the results shows it has good properties.This technology has been applied extensively from 2006 and the yield reached to about 7 million ton annually till now.