This standard defines the characteristics of the layer obtained by thermal diffusion of sulfur, nitrogen and carbon in a ferrous material in the solid state with the sulfontriding treatment and establishes the related control methods. 2 The sulfontriding treatment is mainly carried out on:
——hardened and tempered steels (according to UNI 5332-64);
——cast irons (according to UNI 5007-69 and UNI 5330-69);
——tool steels (according to UNI 2955-68). By direct agreement between the customer and the supplier, the following can also be sulfonitrided:
——unalloyed and low-alloy steels (C^0.20%):
——malleable cast irons (according to UNI 3779-69), spheroidal cast irons (according to UNI 4544-74) and white cast irons ;
——stainless steels (according to UNI 6900-71). 3 The sulfontriding treatment allows to improve the following properties of the material:
——resistance to seizure (anti-welding property);
——wear resistance;
——fatigue resistance.
UNI 7359-1974 history
0000 UNI 10931-2001
1974UNI 7359-1974 Metal carburizing treatment. Sulfur nitriding