Chapter 14.14, Problem 13QP

To determine

To explain:

The factor that affects the hardenability curve when having alloying elements other than carbon.

Answer to Problem 13QP

The factor that affects the hardenability curve when having alloying elements other than carbon is explained below:

Explanation of Solution

The presence of other alloying elements (except carbon) in steel wills results less hardness.

The hardenability curve depicts the ability of the steel to be hardened. The hardenability curve is plotted with the results arrived from hardenability test. The hardenability test involves quenching as the final process, where the specimen is quenched in medium like water or oil. The process of quenching possesses the faster cooling rate that influences the hardness. The cooling rate is low at the distance from the quenched end. This low cooling rate enhances the diffusion of carbon and formation softer pearlite that may mingled with bainite and maternsite. Therefore, the hardenability of steel is increased. The other alloying elements do not encourage this activity. Thus, carbon is the only alloying element that gives more hardness and as well as hardenability whereas the other alloying element does not possess that much hardness and hardenability when compared to carbon.