Controlled rolling controlled cooling can reduce consumption of alloy, reduce production cost, thus is promoted in the seamless steel tube production, and initially formed online often, online quenching and rapid cooling, and other process online.
1, the online process
Online often also referred to as online normalizing, after hot rolling production line pipe rolling process, the steel in the austenite phase zone after air cooling or forced cooling, to get uniform metallurgical structure process.
The process consists of two phase change process:
1) cooling tubes from 1100 ¡æ to 1100 ¡æ, under the steel in the austenite to ferrite + pearlite;
2) after cooling of the seamless steel tube by heating, the ferrite + pearlite steel again into austenite.
Through online often, can make the steel group evenly, ?