Q235特厚钢板生产工艺研究

Research on Production Process of Q235 Ultra-heavy Steel Plate

以250 mm Q235铸坯为研究对象,采用热机械控制工艺(TMCP)和再结晶控制轧制+加速冷却(RCR+ACC)两工艺进行了110 mm Q235C特厚板工业试制,对比了两工艺厚板的组织和性能。结果表明,两工艺钢板组织和性能均满足GB/T 700-88要求。TMCP工艺钢板表面组织为多边形先共析铁素体+贝氏体+少量珠光体,RCR+ACC工艺表面组织为铁素体+贝氏体;其余部位组织均为铁素体+珠光体,且晶粒度基本相当。与TMCP工艺相比,使用RCR+ACC工艺在奥氏体高温区轧制钢板,变形抗力低,有利于降低轧机负荷或实现低速大压下轧制,且省去TMCP工艺中间待温时间,实现了超厚板轧制过程的减量化。

Taking 250 mm Q235 continuous cast slabs as the object of study, the industrial trials of 110 mm gauge Q235 C ultra-heavy steel plate were conducted by using TMCP（thermal mechanical control process） and RCR＋ACC（recrystallization control rolling ＋ accelerated cooling） processes. The microstructure and mechanical properties of both rolling processes were contrasted. The results indicate that the microstructure and mechanical properties of both processes can satisfy the GB/T700-88 requirements. The surface microstructure of the plates rolled with TMCP process is polygonal pro-eutectoid ferrite,bainite and some pearlite, however the surface microstructure of the plates rolled with RCR＋ACC process is ferrite and bainite; the microstructure of the rest parts is ferrite and pearlite, and grain sizes are almost the same. Compared with the TMCP process, the deformation resistance of rolled steel plate in austenite high temperature area by using RCR＋ACC process is low, which is propitious to decrease the load of mill or implement low speed heavy reduction rolling. Moreover, because of leaving out the waiting time for temperature in TMCP process, the ultra-heavy plate steel rolling process is simplified.