Design a process to produce a 05cm diameter steel shaft havi

Design a process to produce a 0.5-cm- diameter steel shaft having excellent toughness as well as excellent wear and fatigue resistance. The surface hardness should be at least HRC 60, and the hardness 0.01 cm beneath the surface should be approximately HRC 50. Describe the process, including details of the heat-treating atmosphere, the composition of the steel, temperatures, and times.

Solution

Vanadium diffusion, chromizing, and boronizing can be used to increase wear resistance and toughness. Boronizing has sufficient hardness with good case depth. Moreover it is not much costly. But the problem is that addition of boron makes brittle layer (FeB). Suitable formulation is necessary to impede the formation of such brittle layer.

Boro-vanadizing can be used. Boro-vanadizing is a thermochemical treatment involving consecutive diffusion of boron and vanadium into the component surface. Boro-vanadizing is a process of two steps, which involves: (i) boronizing and (ii) vanadizing.