高强度热轧搪瓷钢搪烧后组织及力学性能研究

Research on Microstructure and Mechanical Properties of High-strength Hot Rolled Enamel Steel after Enameling

采用加热炉在不同温度下对高强度热轧搪瓷钢进行模拟搪烧实验,观察了实验钢搪烧前后的显微组织并进行了力学性能测试,最后对模拟实验结果进行了实际涂搪验证。结果表明,该热轧高强搪瓷钢的晶粒细小,主要析出物为纳米级Ti C粒子。该搪瓷钢实际涂搪后仍具有较高的强度和断后伸长率,屈服强度≥350 MPa。该搪瓷钢在880℃以上温度进行搪烧时,屈服强度基本不再下降。重要原因是搪烧过程中搪瓷钢的晶粒几乎没有长大,即细晶强化的坚挺作用。而实验钢在搪烧过程中保持细晶的原因之一是锰元素对组织的细化作用,另一个原因是纳米Ti C颗粒的细化作用。

The enameling test of high strength hot rolled enameling steel was simulated at different temperatures by using heating furnace. The microstructure of the test steel before and after enameling was observed, and the mechanical properties were tested. Finally, the simulated experimental results were verified by actual enameling test. The results show that the grains of hot rolled high-strength enamel steel are fine and main precipitates are nanoscale Ti C particles. After practical enameling,the test steel still has high strength and elongation. The yield strength is not less than 350 MPa. When the enameling temperatures is above 880℃, the yield strength basically no longer decreases. The important reason is that the grains of the enamel steel hardly grow up during the enameling process. That is the strong effect of fine-grain strengthening. One reason of maintaining fine grains of test steel during enameling process is that manganese element has refining effect on microstructure.The other reason is the refining effect of nano-sized Ti C particles.