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以9%Ni钢为材料研究了镍钢中“逆转变奥氏体”的形成问题。实验表明;“逆转变奥氏体”(γ′)于540℃开始形成,渗碳体(θ)在540℃以前析出。θ及γ′相与基体(α)之间分别存在Bagaryatskii和Kurdjmov-Sachs取向关系。延长回火时间,γ′相粒子数量增多并长大。提出了γ′相形成的可能机制。讨论了γ′相在较低的回火温度下形成的原因,认为是由于回火过程中合金元素镍在局部地区偏聚引起的。
The formation of “retrogressive austenite” in nickel steel was studied with 9% Ni steel. Experiments show that the “reverse austenite” (γ ’) starts to form at 540 ℃, and the cementite (θ) is precipitated before 540 ℃. The Bagaryatskii and Kurdjmov-Sachs orientations exist between the θ and γ ’phases and the matrix (α) respectively. Extend the tempering time, γ ’phase particles increased and grew up. A possible mechanism for the formation of γ ’phase is proposed. The reason for the formation of γ ’phase at lower tempering temperature is discussed. It is believed that this is due to the segregation of nickel alloying elements in some areas during tempering.