高強度薄鋼板のプレス成形特性におよぼす残留オーステナイトの影響

概要

論文の詳細を見る
Effects of retained austenite on press-formabilities were investigated, using autempered 0.4C-Si-1.2Mn sheet steels with high tensile strength more than 100 kgf/mm^2. The results showed plausible relationships between formabilities and initial fraction of retained austenite (V_γ_0). As V_γ_0 increased, height of stretch forming increased linearly to the maximum at 0.2V_γ_0, and bendability as well as hole expandability of mechanically grinded hole were gradually improved to the best at 0.15∿0.2V_γ_0. On the other hand, hole expandability of punched hole decreased slightly in less than 0.15∿0.2V_γ_0 with V_γ_0 increasing. More than 0.2 or 0.15∿0.2V_γ_0, all of these formabilities decreased extraordinarily. It was concluded that these effects of retained austenite on pressformabilities can be clearly understood in terms of V_γ_0 and k : a rate constant relating rate of deformation-induced transformation with uniaxial tensile strain, as a parameter showing stability of retained austenite in press-forming.
社団法人日本鉄鋼協会の論文
1991-08-01