Here is the conclusion of this series on surface cracking of the compound layer of a gas-nitrided component.

The early and original process can still be used as the measurement of the thermal decomposition of the ammonia process gas. This method employs the simple measurement of dissociation of the ammonia process gas.

It is most interesting to note that the process technology of gaseous nitride is still being used in today’s surface-treatment processing world.

This is the conclusion to David Pye's blog on retained austenite.

The company is using the Alnor dew-point test unit. The Alnor unit has been in the heat-treatment industry since the mid-1920s.

While in the U.K. on metallurgical consulting assignments, the writer was presented with a problem of varying surface hardness due to inconsistent formations of retained austenite on repeated batches of carburized and hardened heat-treated components.

This is a continuation of part 3, which can be found here.

If the steel part has been surface treated by the following, one cannot always grind into the finished surface to prepare for hardness testing.

If the steel is decarburized, it means the surface of the steel has lost carbon. If either of the conditions described in part 1 exists, the steel will have been subjected to...

The result of hardness testing is what is used as the first level of interpreting the correctness of the heat-treatment procedure.