| 摘要 |
<p>A knurled roller or similar device used to create a spark when rubbing on a flint, is made using a steel body with a hard surface layer. The body is low alloy steel contg. 0.6-6% Cr, and >1.8% of elements which promote the formation of nitrides; the steel is immersed for 20-90 mins. in a carbonitriding salt bath. The bath is pref. a mixt. of cyanides and cyanates, contg. (by wt.) 25-43% cyanides, to obtain a surface layer on the steel contg. the nitrides and carbides of iron, where the iron nitrides are >50% and a layer of diffused nitrogen min. 0.ukmm wide is present. The hardness at a depth of 25 mu m below the surface of the treated steel measured using a load of 100 g, is pref. 600-1220 Vickers hardness (HV). Used in the mfr. of cigarette lighter wheels or similar components, where the wheel or roller rubs on a flint of Fe-Si or any other material to cause ignition of a gas or other fuel. The knurled wheel or roller has very high reliability and excellent wear resistance.</p> |
