CB890QL钢履带式起重机臂架用热轧管坯控轧工艺分析

对305 mm x315 mm中间坯以连轧速度0.6-0.8 m/s,开轧温度950 ~ 1 028弋控轧的低碳Nb-V微 合金化CB890QL钢进行组织分析，得出试验钢种在轧制过程中以动态回复为主;在0.8 m/s轧制速度下，进连轧温 度从1028°C降至950°C 钢的晶粒不断细化, Φ200 mm钢也存在晶粒尺寸差异较大的情况；0. 6 m/s的轧制速度 下，随着温度的降低晶粒大小并不是线性变化的。在进连轧温度为980°C ,0. 6 m/s轧制速度下，试验钢可获得较为细小均匀的组织。

Controlled Rolling Process of Hot Rolled Tube Bloom of CB890QL Steel for Crawler Crane

 By analysis on structure of low carbon Nb-V micro-alloying CB890QL steel with control-rolling from 305 mm x315 mm mediate bloom by continuous rolling speed 0. 6 ~0. 8 m/s at 950 ~ 1 028 °C , it is obtained that the dynamic recovery of the tested steel is mainly in rolling process, with the rolling speed of 0. 8 m/s, as the rolling temperature is reduced from 1 028 X. to 950 °C , the grains of steel are refined continuously, and there is also a big difference in grain size. With the rolling speed 0. 6 m/s in Φ 200 mm steel, the grain size does not change linearly with the decrease of temperature. When the continuous rolling temperature is 980 °C and the rolling speed is 0. 6 m/s, the fine and uniform microstructure of test steel can be obtained.