Structure and Mechanical Properties of a Layered Composite Based on Fe–Cr–V Alloy and High-Nitrogen High-Chromium Steel After Hot Pressing and Annealing

A hot pressing method was used to obtain a layered composite consisting of alternating layers of AISI 439 type steel with a high nitrogen content (0.8%) and Fe-20% Cr-5%V alloy with a low nitrogen content (less than 0.02%). Annealing of the composite at T = 700–850 °C after hot pressing leads to diffusion of nitrogen from the nitrided AISI 439 layers into the Fe–Cr–V layers, the formation of diffusion zones containing dispersed vanadium nitrides in the Fe–Cr–V layers and the formation of diffusion zones with a low nitrogen content in the AISI 439 layers. A tendency towards a decrease in the sizes of the vanadium nitride particles with decreasing annealing temperature was revealed. Annealing at T = 750 °C increases the plastic characteristics and reduces the strength characteristics of the composite compared to the state after hot pressing. The presence of dispersed vanadium nitrides precipitated in the composite structure during annealing increases the strength of the composite by 15%.