Effect of Composition and Processing of Ti Microalloyed Steels on Microstructure and Mechanical Properties

摘要

By addition of Titanium (0.04%～0.12% ) , 450MPa～650MPa grade (YS) high strength steels with good impact roughness at lower temperature have been successfully developed by CSP process. OM , TEM and physics-chemical phase analysis were employed to explore the microstructure and properties of high strength steels. Research results showed that the strength of the experimental steel s increase with increase of Ti content when addition of Ti is lower than 0.09%～0.10%, but remain unchanged when addition of Ti is higher than 0.09%～0.10%. Ferrite grain size does not change with Ti content increaseing, precipitates of nanometer size TiC particles in steel s is responsible for increase of the strength.