Study on the material properties and constitutive model of titanium-clad steel

To study the mechanical properties of titanium-clad (TC) steel systematically, a series of tests on TA2+Q235B (2 mm~12 mm thick) TC steel plates are carried out including tension coupon test with various clad ratios, shear test, combine test, bending test, impact test and hardness test. Based on the test results, basic mechanical properties of this kind of TC steel are obtained. In particular, the mechanical properties under monotonic tensile loading are focused on. It is indicated that the characteristics of the stress-strain curves and typical mechanical properties of the titanium-clad steel are directly related to the clad ratio. With an increase of the clad ratio, the yield plateau disappears gradually and the elastic modulus decreases, whilst the yield strength and the elongation increase although the change in tensile strength is insignificant. These phenomena are related to the mechanical properties of titanium (TA2) and low carbon steel (Q235B). Based on the tensile test data and finite element analysis results, a calculation method for determining the mechanical index of the TC steel is developed, and a constitutive model of the TC steel is proposed in this paper. In addition, despite the fact that the strengths obtained from the shear and combine tests were low, their effects on the tensile properties are rather limited. The bending performance and impact properties of the TC steel are good; the hardness of the base layer and cladding layer are higher than that at the bonding interface region. This work may provide basic reference and the material constitutive model for research of the TC steel in structural engineering, and may promote its engineering applications.