The valve rod (steel 35) is nitrided in the fluid softnitriding process, the main material being made up of urea.
采用以尿素为主要原料的液体软氨化工艺，对阀杆(35钢)进行了氮化处理。
2
Since 1974 the research work on gas softnitriding of nodular cast iron crankshafts used in agricultural diesel engine has started.
用气体软氮化强化农用柴油机球铁曲轴的研究始于1974年。
3
This paper has investigated the influence of alloying element Nb on structure and properties of the softnitriding layer by means of experiments of the matrix steels containing Nb and Nbfree.