Methods and related apparatus for continuously evaluating the mechanical and microstructural properties of metal materials, in particular steel, in cold deformation processes

摘要

In cold deformation processes, low strain rates in the range of 1 x 10 ^-4 to 10 x 10 ^-4 s ^-1 for laboratory static conditions and high strain rates in the range of 0.1 to 10 s ^-1 for dynamic conditions A method for continuously evaluating the mechanical and microstructural characteristics of a rolled metal material (L) subjected to a combination of compressive forces, traction forces, and bending moments to be applied, wherein the temperature (T), deformation ( ε) and strain rate ( Measuring the characteristic parameters of the cold deformation process under dynamic conditions, comprising one or more values of), and further comprising the following steps: mechanical and microstructural of rolled metal material (L) A method of continuously evaluating a characteristic is disclosed: Formula (I) ( Calculating a traction yield strength σ _YD at high strain rate, where σ _c is the compressive strength of the rolled sheet L when a compressive force Fc is applied to the rolled sheet L; σ _t is the traction strength of the rolled sheet L when a traction force T _in , T _out is applied to the rolled sheet L; sigma _bend is the bending strength of the rolled sheet L when a bending moment is applied to the rolled sheet L; m, n and p are the first, second and third parameters, respectively, which are a function of the continuously measured operating conditions of the cold deformation process, a function of the rolled sheet L with respect to the chemical composition, and start hot deformation And a function of the preceding operating conditions of the hot deformation process in relation to the termination temperature, the winding temperature and the crystal grain size; -Formula (II) ( Calculating the traction yield strength σ _YS at a low strain rate, where σ _YD is the traction yield strength at the high strain rate; f is a statistical optimization factor between the data measured at low and high strain rates; α is a first characteristic parameter of the rolled sheet L, which is a function of the chemical composition of the rolled sheet L, and a function of the operating conditions of the hot deformation process of the rolled sheet L; β is represented by the formula (III) ( Is a second characteristic parameter of the rolled sheet L, which is a function of the cold deformation process calculated according to Is the strain rate, Q is the activation energy of the strain of the rolled sheet L evaluated through laboratory tests, R is the Boltzmann constant of the ideal gas, and T is the temperature of the rolled sheet L). .