形变累积变形抗力数学模型的研究

MATHEMATICAL MODELS FOR DEFORMATION RESISTANCE ON CONSIDERING RESIDUAL STRAIN ACCUMULATION

本文以奥氏体不锈钢(1Cr18Ni9Ti)为实验材料,对热轧过程中的变形抗力规律作了深入研究,提出在多道次轧制过程中用残余应变系数函数表征形变累积的影响。研究基于对不同参数结构的非线性模型的回归结果,给出了具有良好线性性态的形变累积变形抗力模型: σ_i=σ_oexp[a_1(T_i-1)](?_i/20)^(a_2T_i)[a_4(e_i+Δe_i/0.2)^(a_3)-(a_4-1)(e_i+Δe_i/0.2)]λ_i=λ_o(1/T_i)^(b_1)(e_i/0.2)^(b_2)b_3^(?_i/20)exp(-b_4 T_i/5)式中 σ_o,a_1～a_4,λ_o,b_1～b_4——参数估计,其值取决于钢种; i——轧制道次; T_i=t_i+273/1273; e_i=ln 1/1-ε_i=ln H_i/h_i; Δe_i=ln 1/1-Δε_i; Δe_i=ε_(i-1)(λ_i)+ε_(i-2)(λ_(i-1)λ_i)+…+ε_1(λ_2λ_3…λ_i)。 用上钢三厂实测生产数据对上述模型精度进行了检验,结果表明,在多道次轧制过程中,考虑形变累积效应后,变形抗力的预报精度显著提高,偏差频率为正态分布。

In this paper, the regularity of deformation resistance has been developed during hot rolling processes with experimental material of austenitic stainless steel (1Cr18Ni9Ti) . The effect of strain accumulated in multistage rolling processes can be expressed as a function of the residual strain coefficient. Gn the basis of the regression results of the nonlinear models with varying parameter structures, the mathematical model of deformation resistance with good linear character for considering strain accumulation was put forward: where:parameter estimation, its value depends on the steel type,The accuracy of the above-mentioned models was tested with the operating data of Shanghai No. 3 Steel works. The results was shown. after considering the effect of strain accumulated in multistage rolling processes, the prediction accuracy of the deformation resistance was greatly increased and the deviation frequency was normal distribution.