高强度热轧高扩孔钢的研制与开发

Research and development of ultra-high strength and hot-rolled steel with high hole expansion ratio

以一种低碳微合金钢为研究对象,采用热模拟试验对其连续冷却转变规律进行了研究,并通过实验室热轧进行了高强度热轧高扩孔钢的研制与开发。结果表明,冷速在2~10℃/s时,试验钢组织由铁素体和贝氏体构成,随冷却速率增加,铁素体含量降低。实验室热轧卷取后冷却至室温,所得钢板铁素体含量约为76%,铁素体晶粒尺寸约为5.8μm,抗拉强度大于670 MPa,扩孔率大于90.5%,伸长率大于21.0%。

A kind of low carbon micro alloyed steel as the research object, continuous cooling transformation of the steel was studied by thermal simulation test, and ultra-high strength and hot-rolled steel with high hole expansion ratio was researched and developed by laboratory hot rolled. The results show that the microstructure of the steel is composed of ferrite and bainite under the condition of cooling rate 2-10 ℃/s, and with cooling rate increasing, the percentage of ferrite decreases. In the laboratory the hot rolled and coiled steel is cooled to room temperature, and the percentage of ferrite is 76% , the average size of the ferrite is 5.8 μm. The tensile strength is above 670 MPa and the hole expansion ratio is above 90.5% , the elongation is above 21.0%.