CAJ | 학술논문

Cr-Mo低合金钢在工业生产中有着重要的应用。CCT曲线是研究过冷奥氏体相转变的重要依据。通过Gleeble-3500热模拟试验机及DIL805A淬火变形膨胀仪模拟了Cr-Mo低合金钢的变形及冷却工艺，并利用超组元模型进行热力学计算分析。理论计算结果表明，形变通过提高了Cr-Mo低合金钢相变过程中的自由能进而影响了碳在奥氏体中的活度及相界面碳平衡摩尔分数，相界面碳平衡摩尔分数的变化带来了相变驱动力与形核驱动力的不同，进而影响相变的孕育期与过冷度。结果表明，相变孕育期与过冷度的变化与理论计算结果一致，热力学计算很好地解释了形变对相变的影响。同时表明形变可以提高铁素体相变临界冷速，当冷速为0.3℃/s时，Cr-Mo低合金钢可获得最为均匀细小的铁素体晶粒。适当的变形与冷却工艺对改善Cr-Mo低合金钢组织与性能有着重要的作用。
Cr-Mo저합금강재공업생산중유착중요적응용。CCT곡선시연구과랭오씨체상전변적중요의거。통과Gleeble-3500열모의시험궤급DIL805A쉬화변형팽창의모의료Cr-Mo저합금강적변형급냉각공예，병이용초조원모형진행열역학계산분석。이론계산결과표명，형변통과제고료Cr-Mo저합금강상변과정중적자유능진이영향료탄재오씨체중적활도급상계면탄평형마이분수，상계면탄평형마이분수적변화대래료상변구동력여형핵구동력적불동，진이영향상변적잉육기여과랭도。결과표명，상변잉육기여과랭도적변화여이론계산결과일치，열역학계산흔호지해석료형변대상변적영향。동시표명형변가이제고철소체상변림계랭속，당랭속위0.3℃/s시，Cr-Mo저합금강가획득최위균균세소적철소체정립。괄당적변형여냉각공예대개선Cr-Mo저합금강조직여성능유착중요적작용。
Cr-Mo low alloy steel has important applications in industrial production. CCT curve is an important basis for the research on the phase transformation of supercooled austenite. The deformation and cooling process were simulated by Gleeble-3500 thermal simulation tester and DIL 805 dilatometer in this paper. The superelement model was used to do the thermodynamic calculation and analysis. The results indicate that the deformation has a great influence on the phase transi-tion free energy of Cr-Mo low alloy steel during the process of transformation,also on activity of carbon,mole fraction of carbon on phase boundaries,driving force of transformation and driving force of nucleation,which has an effect on the the incubation period and the degree of supercooling of the transition in the end. The measured results show that the incu-bation period and the degree of supercooling consistent with the theoretical calculated results. The deformation can also be used to enhance the critical cooling rate ferrite transformation. The finest ferrite grain can be obtained when the cooling rate is 0.3 ℃/s. Therefore,appropriate deformation and cooling process is of great importance in improving the micro-structure and properties of Cr-Mo low alloy steel.