Abstract
It is well-known that hardenability of HAZ is one of the important factors for estimating weldability of steels. Therefore the parameter of cooling time from 800 to 500°C (Δt8/5) has been usually used for estimation of the hardenability of lower carbon high strength steels. However it is not clear if for higher carbon steels Δt8/5 is also useful parameter for the estimation, because the Ms temperature of these steels is lower than usual lower carbon steels. For this purpose this paper has investigated the usefulness of application of Δt8/5 parameter for the HAZ of higher carbon steels. Conclusively, it was cleared that the Δt8/3 parameter is better than Δt8/5 for these steels. Then the authors have introduced a new equation for estimation of the HAZ hardness for higher carbon steels. using Δt8/3 parameter.
