Liquid Boriding for Small Cutting Tools

Abstract

In steel surface hardening methods, Boriding produces a layer of uniform hardness from the surface to a depth of the diffusion layer, with high resistance to wear and corrosion. This method can be applied to carbon steels, low alloy steels, tool steels, stainless steels, etc. Specifically for parts subject to high levels of wear, such as valve parts (gates, body/stem, etc.), pump components (housings, cylinders, etc.), agriculture equipment (harvesting cut tools, separators, etc.), and automotive parts (engine oil pumps, gears, etc.). This study focuses on studying the formation mechanism of permeable layer Boriding, the nature of absorbent layer B forming on the steel surface, and exploring the influence of factors such as infiltration temperature, infiltration time, and mixture ratio on the microstructure, properties of the permeability layer Boriding. The salt bath consists of 70% borax + 30% silicon carbide, and the permeability temperature is from 850°C to 1050°C for about 2–10 hours. The results show that the penetration rate is relatively fast, about 0.04 mm/h, and the quality of the layer is relatively uniform. After Boriding, quenching, and tempering, the hardness obtained about 1000–1100 HV.