Al-Zn-Mg合金の応力腐食割れに関する研究-2-2段時効の効果について

概要

論文の詳細を見る
To investigate the effect of split-aging on Weibull distribution of failure times in stress corrosion cracking of Al-5.3wt% Zn-1.4wt% Mg Alloy, tensile tests by constant loading were carried out in 3.5% NaCl+0.2% H202 solution of pH4.0. All test pieces were solidificated at 460℃ for an hour and immediately quenched into ice-water at O℃, and then heat-treated by three types of aging, (1) at 120℃ for 2 days, (2) at 100℃ for 3 days and (3) at 80℃ for 4 days, after pre-aging at room temperature for a week. Nineteen test-pieces on each split aging condition were tested under the applied stress of 80% or 60% of the yield stress. Crack initiation times, crack propagation periods and failure times were measured and plotted on the Weibull probability paper which is widely used in reliability engieering. The experimental results obtained were summarized as follows : (1) Cumulative probability distribution of failure times could be analized as the single Weibull distribution with considering location parameter γ. (2) Shape parameters m in the Weibull distribution of failure times were found to be nearly unity (m ≒ 1) under the applied stress of 80% of the yield stress, and larger than unity (m ＞ 1) under the applied stress of 60% of the yield stress on each aging condition. (3) The aging temperature dependence of the mean failure times and median failure times indicated that the split-aging increased the failure times and the longest failure times were obtaind in the sample (B) split-aged at 120℃, (4) The effect of split-aging was discussed by comparing the sample　(A) reported previously with the sample (B) in cumulative failure distribution function vs time curves and SEM observations of surface fractured.
奈良教育大学の論文

著者

岡敏博
奈良教育大学技術教室

Al-Zn-Mg合金の応力腐食割れに関する研究-2-2段時効の効果について

スポンサーリンク

概要

著者

関連論文

スポンサーリンク