EFFECT OF ACICULAR FERRITE MICROSTRUCTURE COMPOSITION ON STRENGTH OF X65 PIPELINE STEEL
超低碳微合金管线钢中针状铁素体的组成对强度的影响

By using thermo-mechanical controlled processing(TMCP),the acicular ferrite(AF) consisted of different phase constitutions was obtained in an ultralow-carbon micro-alloyed pipeline steel;the effect of phase constitution in AF,which was analysed by quantitative metallography,on the strength was investigated.The results showed that lowering the finish rolling temperature or enhancing the cooling rate obviously improved the strength of the steel,due to increasing of the percentage of granular ferrite and bainitic ferrite in AF;which makes more contribution to the increase of strength than increasing precipitates by enhancing the coiling temperature.