论文部分内容阅读
利用N b(C、N)的微细析出物和晶粒细化机理,开发出了具有优良成形性能的汽车外面板用SFG(超细晶)高强度钢。钢中的N b析出物呈现出目前薄板中所没有的特殊析出形态,并且在晶界附近,有形成PFZ(无析出物区)析出物缺乏层的趋势。由于PFZ的存在,虽然晶粒细小,但也显示出了低屈服强度。另外,-r值也比传统钢高,由于添加了B,使钢板显示出优良的抗二次加工脆性。模拟实际的冲压工艺,采用汽车前挡板的金属冲模进行冲压试验,其结果表明,该开发钢比传统钢具有更宽的成形范围。实践证明,该钢具有优良的成形性能。
Using ultrafine precipitates of N b (C, N) and grain refinement mechanisms, SFG (ultra-fine grain) high-strength steels for automotive exterior panels with excellent formability have been developed. The Nb precipitates in the steel exhibit the special precipitated form that is not present in the current sheet and there is a tendency for the PFZ (precipitate-free zone) precipitate-depleted layer to form near the grain boundaries. Due to the presence of PFZ, although the grain is small, it also shows a low yield strength. In addition, the -r value is also higher than the traditional steel, due to the addition of B, the steel plate shows excellent resistance to secondary processing brittleness. Simulation of the actual stamping process, the use of automotive front baffle metal stamping test results show that the development of steel than the traditional steel has a wider range of forming. Practice has proved that the steel has excellent formability.