Nitriding and cementation are the most popular heat treatments, whose main characteristic is to give a high surface hardness to the mechanical parts treated to resist mechanical wear during their operation. Some mechanical parts, such as gear wheels, shafts, bearings, pistons, require a high surface hardness to resist wear of the contact areas and rubbing and, at the same time, a high capacity of resistance and tenacity of the heart.Hardness and strength are two mostly antithetical properties: they are hardly ever both present in the same material. For example, a low carbon steel is strong, but not hard, while a high carbon steel is hard, but not strong.In order to optimize strength and hardness within the same material, the surface of the material is diversified through heat treatments of cementation or nitriding from the core (surface hardening).
The characteristics of the surface treatment (depth and hardness) depend on the specifications required for the final application, which can range from the defined wear resistance and weight characteristics.
The case depth analysis
It is clear that the control of the depth of the thermally treated surface is of extreme importance for the production of finished parts.
This control is generally carried out by destroying a sample piece from the production batch, using a process that is quite time-consuming and costly (cutting, mounting, surface preparation, microhardness traverse test and analysis of the obtained results).
The innovative solution
With the aim of optimizing the depth control of thermally treated surfaces, Cisam-Ernst has designed and developed a non-destructive method - and therefore extendable to the control of the entire production - able to provide absolutely reliable results in a very short time. The instruments of the HTD line perform the measurement in a fully automatic way on the basis of a proprietary algorithm that allows to detect the thickness from 0.05mm to 2.7mm of the surface treatment in less than a minute.