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《材料科学技术：英文版》
>Comparison between the Methods of Determining the Critical Stress for Initiation of Dynamic Recrystallization in 316 Stainless Steel
Comparison between the Methods of Determining the Critical Stress for Initiation of Dynamic Recrystallization in 316 Stainless Steel
Several methods have been proposed to calculate the critical stress for initiation of dynamic recrystallization (σ_c) on the basis of mathematical methods.One of them is proposed by Stewart et al.in which this critical point appears as a distinct minimum in the (-dθ/dσvsσ) through differentiating fromθvsσ.Another one is presented by Najafizadeh and Jonas by modifying the Poliak and Jonas method.According to this method, the strain hardening rate was plotted against flow stress,and the value ofσ_c was attained numerically from the coefficients of the third-order equation that was the best fit from the experimentalθ-σdata.Hot compression tests were used in the range of 1000 to 1100℃with strain rates of 0.01-1 s^(-1) and strain of 1 on 316 stainless steel.The result shows that Najafizadeh and Jonas method is simpler than the previous one,and has a good agreement with microstructures.Furthermore,the value of normalized critical stress for this steel was obtained u_c=σ_c/σ_p=0.92.
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