Thermal processing method for improving high-speed impact resistance of two-phase titanium alloy

Abstract

A thermal processing method for improving high-speed impact resistance of a two-phase titanium alloy includes the steps of: a, heating a two-phase titanium alloy slab blank step by step; b, using a reversing rolling mode to first perform transverse rough rolling, and then reverse a plate blank for longitudinal rolling, and c, water-cooling the rolled plate, and then performing solution heat treatment and aging treatment. According to the method, the anisotropy of transverse and longitudinal properties of the finished plate can be reduced by using a method of two-stage rolling in a β-phase region and an a+β two-phase region, and in combination with rapid cooling after rolling and solid-solution and aging strengthening heat treatment, high strength and excellent high-speed impact resistance of the product can be ensured, and the protective performance of the material is greatly improved.

What is claimed is: 
     
         1 . A thermal processing method for improving high-speed impact resistance of a two-phase titanium alloy, comprising steps of:
 a. heating a two-phase titanium alloy slab blank, and a temperature and a heat preservation time of each section meeting the following conditions: performing heat preservation for 10-20 minutes at a temperature less than 850° C. in a preheating section, performing heat preservation for 10-20 minutes at a temperature of 1050-1070° C. in a heating section, and performing heat preservation for 60-90 minutes at a temperature of 1040-1060° C. in a soaking section;   b. by means of a reversing rolling mode, firstly performing transverse rough rolling on the slab blank with a rough rolling temperature of 990-1030° C. and a reduction rate of 15-25%, and then reversing the slab blank for longitudinal rolling with a rolling temperature of less than 990° C. and a reduction rate of 10-20%; and   c. water-cooling the rolled blank to a temperature less than 200° C., and then performing solution heat treatment and aging treatment on the cooled blank.   
     
     
         2 . The thermal processing method for improving high-speed impact resistance of a two-phase titanium alloy according to  claim 1 , wherein in step a, the two-phase titanium alloy is a titanium alloy of Ti-4Al-1.5Cr-0.5Mo for special bulletproof armor for special vehicles, and the slab blank is obtained by forging the titanium alloy by means of a process combining high-low temperature upsetting-drawing with extended drawing. 
     
     
         3 . The thermal processing method for improving high-speed impact resistance of a two-phase titanium alloy according to  claim 1 , wherein in step a, a size of the two-phase titanium alloy slab blank is as follows: a thickness of 100-140 mm, a width of 800-1200 mm, and a length of 1200-2500 mm. 
     
     
         4 . The thermal processing method for improving high-speed impact resistance of a two-phase titanium alloy according to  claim 3 , wherein a size of the two-phase titanium alloy slab blank after transverse rough rolling is as follows: a thickness of 60-90 mm, a width of 1200-2200 mm, and a length of 1200-2500 mm. 
     
     
         5 . The thermal processing method for improving high-speed impact resistance of a two-phase titanium alloy according to  claim 4 , wherein a size of the two-phase titanium alloy slab blank after longitudinal rolling is as follows: a thickness of 6-20 mm, a width of 1200-2500 mm, and a length of 4000-12000 mm. 
     
     
         6 . The thermal processing method for improving high-speed impact resistance of a two-phase titanium alloy according to  claim 1 , wherein in step c, the solution heat treatment is to perform heat preservation for 1-2 hours at a temperature of 850-900° C. 
     
     
         7 . The thermal processing method for improving high-speed impact resistance of a two-phase titanium alloy according to  claim 1 , wherein in step c, the aging treatment is to perform heat preservation for 8-12 hours at a temperature of 500-600° C.