{"id":14184,"date":"2026-07-09T10:50:23","date_gmt":"2026-07-09T08:50:23","guid":{"rendered":"https:\/\/www.seitelettronica.it\/?p=14184"},"modified":"2026-07-14T12:10:14","modified_gmt":"2026-07-14T10:10:14","slug":"induction-heat-treatments-steel-hardening-tempering-annealing","status":"publish","type":"post","link":"https:\/\/www.seitelettronica.it\/en\/induction-heat-treatments-steel-hardening-tempering-annealing\/","title":{"rendered":"Induction heat treatments: steel hardening, tempering, annealing"},"content":{"rendered":"

Induction heat treatments<\/strong>, including hardening, modify the mechanical properties of steel thanks to rapid and controlled heating<\/b>, followed by a cooling phase whose speed varies according to the treatment and the desired result.<\/p>\n

In this article, we explain how hardening, tempering, and annealing work, how they differ, and why precise temperature control<\/b> makes a difference in the final result.<\/p>\n

In industrial applications, in fact, the success of a heat treatment depends not only on reaching the required temperature but on the ability to repeat it precisely cycle after cycle, keeping all process parameters constant.<\/b><\/p>\n

We then present the induction heating technologies<\/b> designed and manufactured by SEIT Elettronica<\/b>, which offer companies advantages in terms of accuracy, control, and repeatability in industrial processes, including automated ones.<\/p>\n

Induction hardening: what it is and how it works in steel heat treatments<\/strong><\/h2>\n

Hardening is the heat treatment that increases the hardness of steel. With induction technology, the heating phase takes place in a localized and repeatable manner, a condition that allows reaching the required temperature targets without heating the entire component.<\/p>\n

This feature is particularly useful when it is necessary to treat only a specific zone of the component, <\/b>limiting deformation and preserving the mechanical properties of the parts not affected by the treatment.<\/p>\n

What is induction hardening and what is it used for<\/strong> <\/b><\/h3>\n

Induction hardening<\/b> is a heat treatment that brings steel beyond its upper critical temperature (Ac3)<\/b>, i.e., the threshold at which the structure transforms completely into austenite, and cools it rapidly, so as to transform the structure of the material, making it harder and more wear-resistant. It serves to improve the mechanical performance of components subjected to high loads or continuous friction.<\/p>\n

A frequent example is the hardening of industrial springs<\/b><\/a> made of AISI 420 stainless steel. With the induction heating<\/b><\/a> technologies by SEIT Elettronica<\/b>, the piece, obtained by bending the sheet metal when it is still soft, is brought to 1100 \u00b0C in a few seconds and then rapidly cooled<\/b>: it is this sequence that gives it the hardness and elasticity necessary to withstand repeated loads, maintaining the ability to return to its original shape.<\/p>\n

How induction heating works<\/strong><\/b><\/h3>\n

Induction heating exploits an alternating electromagnetic field<\/b> generated by an inductor<\/b>: the induced currents generate heat directly within the conductive material, without contact and without flame. <\/b>The depth of heating depends on the working frequency, the characteristics of the material, and the geometry of the inductor.<\/p>\n

The generator brings the piece to temperature, but the result of the treatment depends on knowing exactly which temperature is reached: <\/b>for this reason, the thermal data must be detected and transmitted in real time.<\/p>\n

Compared to traditional furnace methods, induction hardening offers concrete advantages:<\/p>\n