Originally Posted by HuFlungDung  How does the lead in the steel affect the heat treatment? What about sulferized steels? Or does the lead or sulfer get cooked out of the surface during carburizing anyway? |
Whether or not the lead does anything during the carburizing, I think the purpose of the lead defeats the case hardening. Leaded steel has a low yield strength, it is noticeably softer to plastic deformation than 1018 or even A36. Putting a case on leaded is something like putting a skin of ice on soft snow; I think if it is subjected to an appreciable load it is likely to deform under the case which is likely to crack. This forms a perfect starting point for a fatigue crack and leaded is more fatigue prone that non-leaded low carbon steels. I would never contemplate using leaded in an application requiring a hard surface.