Effect of Heat Treatment Temperature on the Microstructure and Properties of Titanium-Clad Steel Plate Prepared by Vacuum Hot Rolling

Titanium-clad steel plates are widely used in chemical equipment and nuclear power equipment due to their excellent corrosion resistance and high strength. However, the Ti-C and Fe-Ti compounds generated easily at the titanium/steel interface deteriorate the bonding strength of titanium and steel, especially in high-temperature service environments. In this study, pure Fe DT4 was chosen as an intermediate layer to control the formation of interfacial compounds. The plates of titanium/DT4/steel were manufactured by hot rolling technology with a small hole vacuuming. Then, titanium-clad steel plates were annealed at temperatures of 450 degrees C, 550 degrees C, and 650 degrees C to modify microstructure and properties. The interfacial microstructure composition, mechanical properties of titanium-clad steel plates, and the corrosion resistance property of titanium plates were studied in the as-rolled state and under different annealing temperatures. The results showed that compounds of TiC, FeTi, and Fe2Ti were generated at the interface of titanium-clad steel plates in the as-rolled state. After the annealing treatment, the types and quantities of the interfacial compounds were reduced, and these compounds were mainly TiC and FeTi at an annealing temperature of 450 degrees C. The interfacial compound was only TiC at an annealing temperature of 550 degrees C. However, the compounds of TiC and FeTi appeared at the interface at an annealing temperature of 650 degrees C. The variation of interfacial compounds determined the hardness and the shear strength of the titanium-clad steel plates. The more the interfacial compounds, the higher the hardness and the lower the shear strength. Therefore, when the annealing temperature was 550 degrees C, the interfacial hardness was lowest and the shear strength was highest. Meanwhile, the corrosion resistance of the titanium-clad plates showed significant improvement, indicating that this temperature provides favorable conditions for enhancing the corrosion performance of the plate.