轧制工艺对经济型 X80管线钢组织和显微硬度的影响

摘要

Simulating rolling was carried out for traditional X80 pipeline steel and lowcost X80 pipeline steel using Gleeble-1 500 thermal simulated test machine,the effects of deformation temperature,cooling rate and finish cooling temperature on microstructures and microhardness were studied.The results show that microstructures of the two tested steels were acicular ferrite,quasi-polygonal ferrite and granular bainite,and their microhardness had little difference.With the decrease of the deformation temperature and final cooling temperature,the increase of the cooling rate,the microstructure of lowcost X80 pipeline steel was refined and M/A island changed from rods to dots with smaller size gradually,and the microhardness of lowcost X80 pipeline steel had a little fluctuation.%利用 Gleeble-1500D 型热模拟试验机对传统型 X80管线钢和经济型 X80管线钢进行模拟轧制,研究了变形温度、冷却速率和终冷温度等工艺参数对其组织和硬度的影响。结果表明：两种试验钢的组织均为针状铁素体、少量准多边形铁素体和粒状贝氏体,二者的显微硬度相差不大；随着变形温度降低、冷却速率增大和终冷温度降低,经济型 X80管线钢的组织逐渐细化,M/A 岛由棒状逐渐变成圆点状,尺寸变小,显微硬度的波动不大。