钛微合金化700MPa级汽车大梁钢的研究

Study of Ti Microalloying 700 MPa High Strength Automobile Frames Steel

通过中试热轧试验，仅采用钛微合金元素进行强化，获得了抗拉强度为745～760MPa、下屈服强度为640～655MPa和断后伸长率为23.0％～23.5％的热轧板。试验结果表明，下屈服强度和抗拉强度基本与终冷温度呈线性关系，且随终冷温度的降低而明显升高；等温卷取更有利于钛的充分析出，且卷曲温度越低钛的析出量越少。

The Ti microalloying hot plate was produced with the tensile strength of 745～760 MPa, lower yield strength of 640～655 MPa, and elongation of 23%～23.5% through pilot-scale hot rolling tests. The results indicated that both the lower yield strength and tensile strength showed a linear relationship with the final cooling temperature, and were increased significantly with the decrease of the final cooling temperature. Precipitation of Ti was improved through isothermal coilong, and the lower the coiling temperature, the less the precipitation of Ti was.