摘要
为发展热轧棒材双相钢,本文就化学成份、终轧温度及轧后冷却工艺与铁素体——马氏体双相钢的组织形成和机械性能之间的关系进行探索。结果表明:对一般低合金和含碳量在0.15～0.35％的碳钢,终轧温度控制在Ar_3±30℃,轧后立即水冷或空冷几秒再水冷至Ms以下;若终轧温度控制在1000℃左右,轧后应立即水冷至Ar_3,并缓慢冷却数秒后再水冷至Ms以下均可获得双相组织和良好的综合机械性能。在Ar_3附近缓慢冷却,可迅速形成铁素体,使奥氏体、铁素体两相分离。钢中含碳量增加,强度上升塑性下降;而锰和硅在一定含量范围内,可增加强度而对塑性影响较小,最后对冷却装置进行讨论,并设计出适合实际生产使用的喷水冷却装置。
This paper, deals with the relationship between chemical composition, finish rolling temperature, cooling process, forming conditions of the ferrite-martensite structure and the mechnical properties of dual-phase steel bar. The result indicated that for 20Mn2 and carbon steel which contains carbon from 0.15 to 0.35 percent, the finish roiling temperature is controlled around about Ar_3± 30℃ After being hot-rolled, the steel bar must be water-cooled or air-cooled to Ms temperature. If the finish roiling temperature is over 1000℃ after being rolled. the steel bar must be immediately water-cooled to At_3 followed by cooling slowly for several seconds and then cooled in water till below Ms. The above cases can result in the dual phase structures and good combined mechanical properties. If steel is cooled slowly around the At_3, the ferrite will be will be quickly formed and the ferrite be separated from the austenite. It has been found that increase of carbon content leads to increasing strength and lowering ductility. However, in the certain range of Mn and Si contents strength increases while duetil ity is affected slightly. Discussions are also given on special cooling equipment and a type of cooling equipment suitable to the practical production has been designed.
出处
《上海金属》
CAS
1990年第1期60-65,共6页
Shanghai Metals
