低成本Q355B热轧带钢生产工艺研究与实践

Research and Practice on Production Technology of Low Cost Q355B Hot Rolled Strip Steel

Q355B热轧带钢主要用于制作管件、光伏支架、高速护栏、冷弯型钢和家电家具配件。为提升经济效益,做大做强市场,优化了矩形坯化学成分和控轧控冷工艺,在650带钢连续生产线应用三叉区立式超快冷工艺和层流冷却工艺,实现采用低成本的Q235B矩形坯减量化轧制Q355B钢种。生产实践结果表明:产品力学性能符合标准要求,成品尺寸、板形及表面质量良好,金相组织为铁素体+珠光体,铁素体晶粒度11.5~12.0级,满足用户需求。

Q355b hot rolled strip steel is mainly used to make pipe fittings,photovoltaic supports,high-speed guardrails,cold-formed steel sections,household appliances and furniture accessories.In order to improve economic benefits and expand and strengthen the market,the chemical composition of rectangular billet and controlled rolling and cooling process are optimized.The triple zone vertical ultra fast cooling process and laminar cooling process are applied in the 650 strip continuous production line to realize the reduction rolling of Q355B steel with low-cost Q235B rectangular billet.The production practice results show that the mechanical properties of the product meet the standard requirements,the size,shape and surface quality of the finished product are good,the metallographic structure is ferrite+pearlite,and the ferrite grain size is 11.5~12.0,which meets the needs of users.