铝包钢线材连续冷却转变曲线

Continuous Cooling Transformation Curves of LBX87A

在Formastor—F热模拟试验机上利用热膨胀-金相法测定了含碳量为0.87%的铝包钢LBX87A在不同冷却速度下连续冷却转变的膨胀曲线,利用金相显微镜观察了不同冷却速度下的金相组织,并测定了各个试样的硬度值,建立了该钢的连续冷却转变曲线(CCT)。结果表明,当冷却速度≤0.5℃/s时,钢中存在网状碳化物,当冷却速度为2℃/s左右时,获得索氏体+珠光体组织,当冷速≥10℃/s时,钢中有马氏体组织产生。

Using the thermal expansion-metallography method and the Formastor- F thermal simula-tor, LBX87A steel？s expansion curve of continual cooling transformation under different cooling rate was measured,resulting in the continual cooling transformation curve（CCT curve） of the steel. And the micro-structure with different cooling rate was observed through microscope. Also the rigidity was measured. And then, the CCT curves of LBX87A was established. It was stated that with cooling rate 2℃/s , the steel had ferrite and pearlite structure, with cooling rate less than 0. 5℃/s , the steel had net carbonization and with cooling rate more than 10℃/s , there had martensite in steel.