差示扫描量热法测定22Mn2SiVBS钢CCT曲线

MEASUREMENT FOR CCT CURVE OF 22Mn2SiVBS STEEL BY DIFFERENTIAL SCANNING CALORIMETER

在STA-409PC型同步热分析仪上,利用差示扫描量热法对自行设计的低碳空冷贝氏体钢(22Mn2SiVBS钢)进行相变点的测定和显微组织观察,并结合相变点的计算公式对比分析,绘制钢的CCT曲线,验证理论计算公式的正确性。结果表明:该钢的奥氏体转变开始温度A1点为732℃,转变终了温度A3点为836℃;珠光体临界冷却速度是(vP)0.667℃/s,铁素体临界冷却速度(vF)1.16℃/s,与理论计算结果符合较好;控制该钢的轧(锻)后空冷速度为:vF≤v实际<vB,可以得到以粒状贝氏体为主的显微组织,钢具有强韧性配合良好的力学性能。

Transformation point and microstructure of self-designed low carbon air cooling bainite steel 22Mn2SiVBS was tested using differential scanning calorimeter on STA-409PC synchronism thetmal analyzer, and by contrast and analysis for theoretical transformation point formula, the C.CT curve was drawn. and the correctness of theoretical formula was validated. The result show that the beginning temperature of the austenite transformation is 732℃, the ending temperature of the austenite transformation is 836℃;the critical cooling rate of pearlite（vp） is 0. 667℃/s, the critical cooling rate of ferrite（vF） is 1.16 ℃/s, it accords with theoretical value commendably; When the air cooling rate is controlled as vF≤vrure〈vB, it can obtain the microstructure consisting mostly of granular bainite, the steel has the combination of excellent strength and toughness.