高寒地区公路护栏用热轧钢带的生产开发

Smelting and Development of Hot-rolled Steel Strip for Highway Guardrail in Alpine Region

高寒地区气候复杂恶劣,对高速公路防护栏用钢带的低温冲击韧性及韧脆转变温度有极高要求。用低碳高锰加Nb-Ti微合金化的成分体系,通过控轧控冷工艺成功开发出3.0 mm厚高寿命高寒地区高速公路护栏用高强韧耐低温钢带。产品性能:屈服强度≥450 MPa,抗拉强度520~680 MPa,断后伸长率≥27%,-20℃冲击功≥20 J,以珠光体+铁素体混合组织为主,晶粒度≥9级,满足高寒地区高速公路护栏对强韧性、弯曲、耐低温性能的实际要求,使用寿命可达10~25 a,是传统高速护栏Q235B结构钢的2倍以上。

The climate in the high cold region is complex and harsh,so the low temperature impact toughness and the tough-brittle transition temperature of the steel belt used for highway guardrail are very high.The high strength and low temperature resistant steel belt with 3.0 mm thickness and long life for highway guardrail in high cold area has been successfully developed by the controlled rolling and cooling process with the composition system of low carbon and high manganese plus Nb-Ti microalloying.Product performance:Yield strength is more than 450 MPa,tensile strength 520-680 MPa,elongation after breaking is more than 27%,impact power is more than 20 J at-20℃,mainly with the mixed microstructure of perlite+ferrite,grain size is more than grade 9.It can meet the actual requirements of high cold area highway guardrail on strength toughness,bending,low temperature resistance performance,service life up to 10-25 a.It is more than 2 times of the traditional high-speed guardrail Q235B structural steel.