Study on the interface of direct hot rolling titanium-clad steel plates

摘要

In this study,the interface characteristics of a direct hot rolling titanium-clad steel plate were analyzed,and the mechanism of interface cracking was explored. The detrimental effect from the formation of TFe,TiC,and a Si-enriched layer on the bonding strength was clarified,and an industrial-scaled titanium-clad steel plate with shear strength over 200 MPa was produced with a carefully set schedule accordingly. It was found that hot rolling titanium-clad steel plates had a flat interface without obvious cracks. In the rolling process,both Ti and Fe atoms interdiffused,but Fe diffused much faster than Ti. The Fe-diffused area consisted of three regions. After a high temperature heat treatment,the diffusion depth of Fe and Ti elements increased significantly and evident Si segregation and TiFe layers were identified. Thermal cracking initiated in the Si segregation layer and then propagated along the TiFe layer and Fe-diffused layer on the titanium side.