3. Choosing a steel for heat treatment

To obtain the desired mechanical performance, the steel must be selected taking into account its heat treatment.

But before deciding on the choice of steel, the mechanic needs to make a systematic inventory of all the requirements he needs for his part in service, as well as those imposed by the manufacturing conditions he has decided to adopt. He must then translate these requirements into terms of mechanical or other properties that the steel must possess, provisionally to facilitate manufacturing and, above all, definitively to ensure the expected service.

At this stage, the mechanic can take into account the fact that it is possible to supply bars already treated (by quenching and tempering), which will simplify processing by speeding it up and avoiding the need to take into account the deformations caused by heat treatment. The use...