HEAT TREATMENT OF VK4 ALLOY

In this work, we studied the effect of multiple, stepwise hardening with intermediate tempering on the physical, mechanical and operational characteristics of hard alloys. Alloy VK4 was used as the initial material (non-resurfacing 4-sided plates and sticks with a size of 5×5×35 mm). The physical and mechanical properties of the initial hard alloys WC-Co (VK4) were determined. Then, prospecting work was carried out on 11 modes of heat treatment in salt baths. In each mode,10–15 plates were examined. After conducting prospecting studies, the stages and structural changes in the process of double heat treatment of sintered hard alloys were established. The physical properties of the VK4 hard alloy after heat treatment practically did not change (the coercive force increased by 2 times), however, an increase of 10–30% in ultimate strength in compression and hardness was noted. As a result of the tests carried out, it was found that the plates treated by the proposed methods of heat treatment increased their durability by 1.5–2 times.