The research and Practice of reducing X80 pipeline steel mixed crystal structure

摘要

The low cost X80 pipeline steel with high Nb,low Cu,Ni,Mo production technics,the process parameter control is inappropriate with high Nb steel,it is easy to produce in the mixed crystal phenomenon,resulting in decreasing the toughness and uneven performance.This paper uses Gleeble 3500 thermal simulation testing machine research low cost X80 pipeline steel deformed austenite recrystallization behavior,identify the completeness recrystallized,partial recrystallization and non-recrystallization region,provides the production site to make reasonable control rolling process and theoretical foundation and necessary datas.Recommended that the production from 950 degrees to 980 degrees temperature zone without rolling,prevent partial recrystallization temperature zone by mixing crystal,effectively avoid mischcrystal structure brings the performance deterioration,improve product quality and grade X80 pipeline steel.