摘要
采用THERMECMASTOR—Z热模拟试验机研究25MnVK钢变形奥氏体在连续冷却过程中的相变规律,用膨胀法结合金相组织以及硬度值测定该钢的连续冷却转变曲线(CCT)。结果表明,该钢的奥氏体化温度为920℃。当连续冷却速度小于2℃/s时得到的组织为铁素体+珠光体,大于2℃/s时出现贝氏体,大于50℃/s出现马氏体组织,所以通过控制不同的冷速,可以得到适合的组织。为制定25MnVK钢加热制度和控冷工艺提供了基本条件。此外V的加入使得钢的组织转变得到明显的推迟,CCT曲线右移,钢的淬透性得到提高。
The law of phase transformation of the deformed austenite of 25MnVK steel during continuous cooling was investigated by means of THERMECMASTOR-Z thermomechanical simulator. The CCT curves were obtained by way of thermal dilation method as well as the metallographical examination and rigidity measurement. Results show that the austenite unfrozen temperature of this steel is 920 ℃ and when continuous cooling rate is less than 2 ℃/s the microstructures obtained are ferrite plus pearlite, and when continuous cooling rates exceed 2 ℃/s and 50 ℃/s the bainite and martensite will happen respectively and therefore by controlling the cooling rate the appropriate structure can be obtained. These special features provide a basic condition for preparation of the reheating schedule and accelerated cooling process of 25MnVK steel. Moreover,addition of V element in steel obviously delayed the structure transformation and shifted CCT curves to the right. Furthermore hardenability of the steel is greatly improved.
出处
《武钢技术》
CAS
2008年第1期38-41,44,共5页
Wisco Technology
