How to choose the rolling temperature of titanium and titanium alloys?

Hot rolling should generally be carried out in the β or α+β phase region. The hot rolling temperature is 50~100℃ lower than the forging temperature. Plates with a thickness of 2~5mm can be warm rolled, and thinner plates can be cold rolled. The cold rolling deformation between two annealings during cold rolling is 15%~60%.

 

Titanium and titanium alloys are metals with phase changes. The selection of slab heating temperature must take into account the process plasticity, deformation resistance and the effect of the air absorption layer on the surface plasticity of the rolled product at high temperature in the α+β phase region. The process plasticity of the β phase region is better than that of the α phase region, and the deformation resistance is low. However, the high heating temperature increases the depth of the air absorption layer, and serious cracks will occur on the surface during uneven deformation.

 

The hot rolling of titanium plate is carried out in the β phase region, which can ensure good process plasticity, and the total processing rate of the blanking can reach 90%. Pure titanium TA1, TA2, and TA3 are generally heated at 850~870℃ below the phase transition point, while TC4 should be selected at the upper limit of the α+β phase transition point or adopt superplastic forming process (heating at 1000~950℃). TC1, TC2, TC3, etc. have slightly poor plasticity during hot rolling. The thicker the slab, the more serious the cracking of the edge and the surface cracks due to uneven deformation during rolling. Although TA7 has good oxidation resistance, it has a high degree of alloying and high deformation resistance. Therefore, the heating temperature of TA7 thick slab is selected in the β phase region, which is more conducive to deformation, and can make full use of the alloy plasticity and reduce the number of tempering times.