Influence of Some Technological Parameters of Fluidized Bed Carbonitriding on the Surface Hardness of Carbonitrided Parts from Low Alloy Steels

The paper describes the experimental research of thermos-chemical treatment of carbonitriding performed on samples of different brands of low alloy steels. The technological parameters whose influence on the carbonitrided surfaces hardness was studied are thermo-chemical treatment temperature and the percentage of ammonia in the carbonitriding medium. Thermo-chemical treatments of carbonitriding have been carried out at low, medium and high temperatures. The investigations were conducted with three values for the ammonia percentage, which lead to different results for the surface hardness of the samples subjected to the investigations. The duration of treatment of two hours and thirty minutes, constant for all experiments performed, was chosen as the one commonly used in gas carbonitriding technologies.