9Mn2V钢淬火冷却时VC析出机制的热力学和动力学分析

Thermadynamic and Kinetic Analysis of VC Generation Mechanism in 9Mn2V Steel Quenching Process

通过对VC生成热力学和动力学计算,分析研究了9Mn2V钢冷却过程中VC夹杂物的析出规律以及夹杂物长大的影响因素。本论文的主要结论为:在820℃以上,碳和钒均能完全溶于奥氏体中。当温度降到临界温度以下时,VC并不能立刻析出。随着温度降低,VC析出的驱动力也越大,形核临界尺寸越小。但在较低温度下,由于元素扩散能力变差,析出的VC就会相对减少。VC主要在500～800℃温度范围内析出,临界核心尺寸约在0.65～1.2 nm。

According to the thermodynamic and kinetic calculation of VC,the precipitation rule of VC inclusions in cooling process of beating steel 9Mn2V and the influence factors of inclusion growing are analyzed and studied. The paper＇s main conclusions are as follow： vanadium is completed solid solution in austenite at the austenite range, no apparent role in preventing austenite grain growth. Above 820℃, the carbon and the Vanadium are completely dissolved in the austenite. When the temperature drops below the critical temperature, the VC does not immediately precipitate. VC precipitated as the temperature decreases, the driving force is greater, the smaller the critical size of the nucleation. However, at lower temperatures, due to the deterioration of the element diffusion capacity, precipitated VC will be relatively reduced. VC precipitates in the temperature range of 500 ～ 800℃, the critical core size of about 0.65 ～ 1.2nm.