Dynamic properties of iron and a variety of steels over a wide range of strain rates

利用SBTS（Saginomiya）型高速材料试验装置，在10 ~ 10 ~ 3s ~ 3量级的大应变率范围内，系统地获得了铁和各种钢的拉伸应力-应变曲线，该曲线涵盖了黑色金属材料群的大范围强度等级<-3><-1>。试验材料为电解纯铁（LW 1）、超低碳无铬轧制钢（SPCE ; 270 MPa级IF钢）、冷轧纯铁（PF）、冷轧软钢（SPCE）、冷轧碳钢（SPCC）、冷轧高强度钢（SPFC 440和SPFC 590）、DP 590、1200 MPa级马氏体型高强度钢（MT）和1500 MPa级马氏体型高强度钢（M1500）。通过对这些结果的系统分析，明确了黑色金属材料组在大应变范围内的流变应力的应变率敏感性，包括高应变率下的粘性项、铁和钢的真断裂强度和真断裂应变。得到了新的统一的本构模型（谷村-三村屈服模型）的参数值。一组可用于均匀变形，另一组可用于扩展到真实断裂应变的宽应变范围。这两组都可以用来模拟属于黑色金属材料组的任何材料在宽应变率范围内的应力-应变曲线，只要预先知道有关材料的准静态拉伸应力-应变曲线。

The tensile stress-strain curves of iron and a variety of steels, covering a wide range of strength level, which compose a material group of ferrous metals, over a wide strain rate range on the order of 10^<-3>〜10^3 s^<-1>, were obtained systematically by using the Sensing Block Type High Speed Material Testing System (SBTS, Saginomiya). The tested materials are an electrolytic pure iron (LW1), an ulutra-low carbon interstitial-free miled steel (SPCE ; 270 MPa grade IF steel), a cold rolled pure iron (PF), a cold rolled mild steel (SPCE), a cold-reduced carbon steel (SPCC), cold rolled high strength steels (SPFC440 and SPFC590), DP590, a 1200 MPa grade martensitic type high strength steel (MT), and a 1500 MPa grade martensitic type high strength steel (M1500). Through intensive analysis of these results obtained systematically, the strain rate sensitivity of the flow stress for the large strain region, including the viscous term at high strain rates, the true fracture strength and the trure fracture strain of iron and steels, over the wide range of strain rates, were cleared for the material group of the ferrous metals. New unified sets of values of parameters of the modified constitutive model (Tanimura-Mimura Yield Model) were obtained. One set can be used for homogenous deformation and the other can be used for a wide strain range extended to the true fracture strain. Both of the sets can be used to simulate the stress-strain curves of any material belonging to the material group of ferrous metals, over a wide strain rate range, as long as the quasistatic tensile stress-strain curves of the material concerned is known in advance.