Особенности формирования структуры, эксплуатационных свойств и качества поверхностного слоя штамповой оснастки из стали 3Х2В8Ф

Abstract

The purpose of the article is to study the formation of performance properties and quality parameters of the surface layer of 3KH2V8F (3Х2В8Ф) die steel used in manufacturing of tooling for hot bending of titanium shields by technologically sequential operations including high-temperature diffusion boroaluminizing and final machining. The methods of optical microscopy and X-ray phase analysis are used to determine the structural-phase state. Studies are conducted to determine the roughness and microhardness of the surface layer. Boroaluminizing at a temperature of more than 1050°C results in the formation of diffusion layers with a composite structure on the steel surface. After processing at 950°C a diffusion layer with a layered structure is formed. It is found that the surface roughness after the boroaluminizing at 950°C increases up to Ra 4 µm while processing at the temperature of 1050°C increases the roughness up to Ra 7.7 µm whereas the initial roughness in both cases is Ra 1.5. Finishing grinding used as final machining decreases roughness from the above values to Ra 0.09 µm and Ra 0.43 µm, respectively. Finishing grinding provides the required surface quality while maintaining the functional properties of the diffusion layer. It should be mentioned that the issues of technological support of performance properties must be considered in a complex.