内部および有効応力をパラメータとした応力緩和過程の解析

概要

論文の詳細を見る
In this paper is presented analysis of stress relaxation at elevated temperature by using assumptions, (1) that the relaxation of the applied stress (σ) consists of two relaxation processes of internal stress (σ_i) and effective stress (σ_ε), (2) that the decrement of σ_i is defined by the Bailey-Orowan equation, and (3) that the plastic strain rate ε^^・_p at stress relaxation is expressed by the relation ε^^・_p=A exp(ασ_e), where A and α are constants. From this analysis, the following conclusions have been given. (1) Relaxation mainly depends on the decrement of σ_ε in the earlier stage and in the later stage on the decrement of σ_i. (2) The relaxation properties after re-loading are determined by the magnitude of instantaneous internal stress. If re-loading is carried out in the period where σ_i is larger than the initial internal stress, relaxation resistance is increased, and if re-loading in the period where σ_i is smaller, relaxation resistance decreases. (3) Relaxation rate in the later stage is approximately represented in the following equation, σ^^・≌-r/(1+h/E) where r is the rate of recovery, h the coefficient of work hardening, and E is Young's modulus. (4) If r and h for creep can be substituted with those for relaxation, the following relation between the minimum creep rate ε^^・_c(=r/h) and relaxation rate ε^^・_r(=-d/E) is obtained. ε^^・_c>ε^^・_r Putting the stress exponents of these strain rate as n_c for creep and as n_r for relaxation, the inequality n_c>n/r is also obtained. However there are such cases where these relations fail for the certain kind of steel accompanied by such structural changes as strain aging.
社団法人日本材料学会の論文
1971-07-15

内部および有効応力をパラメータとした応力緩和過程の解析

スポンサーリンク

概要

著者

関連論文

スポンサーリンク