Nitriding method, and a method of manufacturing nitride parts

To ensure constant case depth, capable of suppressing the formation of the compound layer, to provide a nitriding processing method of the low alloy steel. Heating the low alloy steel five hundred and fifty to six hundred twenty ° C., the total processing time A as 1.5 to 10 hours, to implement the At high Low Average K Here, i is an X or Y.