A thermal treatment process of a ferrous alloy sheet is provided. The process includes the step of performing a thermal treatment on said sheet when running, by immersing it into at least one molten oxides bath. The molten oxides bath has a viscosity lower than 3.Math.10.sup.1 Pa.Math.s, the surface of the bath is in contact with a non-oxidizing atmosphere and the molten oxides are inert towards iron. The difference between the temperature of the ferrous alloy sheet at the entry of the bath and the temperature of the bath is between 25 C. and 900 C. The residues of oxides remaining on the surfaces of the ferrous alloy sheet at the exit of the bath are eliminated. A device for implementing this process is also provided.

A method for producing a rolling bearing component includes forming the rolling bearing component from a 100CrMnSi6-4 or 100Cr6 rolling bearing steel, heating the rolling bearing component, quenching the rolling bearing component, heating the rolling bearing component and holding the rolling bearing component. The rolling bearing component to heated to an austenitizing temperature to form an austenitic microstructure. The rolling bearing component is quenched in a hot salt bath to a first temperature of between 170? C. and 200? C. such that there is a pearlitic or ferritic microstructure in a core region of the rolling bearing component. The rolling bearing component is heated to a second temperature between 220? C. and 280? C. The rolling bearing component is held at the second temperature for a holding time of at least 7 hours such that there is a predominantly bainitic microstructure formed on a surface of the rolling bearing component.

A method for producing a rolling bearing component includes forming the rolling bearing component from a 100CrMnSi6-4 or 100Cr6 rolling bearing steel, heating the rolling bearing component, quenching the rolling bearing component, heating the rolling bearing component and holding the rolling bearing component. The rolling bearing component to heated to an austenitizing temperature to form an austenitic microstructure. The rolling bearing component is quenched in a hot salt bath to a first temperature of between 170? C. and 200? C. such that there is a pearlitic or ferritic microstructure in a core region of the rolling bearing component. The rolling bearing component is heated to a second temperature between 220? C. and 280? C. The rolling bearing component is held at the second temperature for a holding time of at least 7 hours such that there is a predominantly bainitic microstructure formed on a surface of the rolling bearing component.

A method of manufacturing a component of a rolling-element bearing includes: providing a steel body having a carbon content of less than 0.3 weight-%, a chromium content of greater than 8.0 weight-%, and a nitrogen content of less than 0.1 weight-%; high-temperature solution nitriding the steel body; after the high-temperature solution nitriding, performing an intermediate tempering process to reduce a size of austenite grains in the steel body; and after the intermediate tempering process, performing a reaustenitizing annealing. Also the component made by the method.

A cold rolled and hardened martensitic austenitic stainless steel strip for flapper valves in compressors is made from steel combining, in weight %(wt. %), the following elements: C: 0.3-0.5, Si: 0.2-0.8, Mn: 0.2-1.0, Cr: 12.0-15.0, Mo: 0.50-2.00, N: 0.02-0.15, and V: 0.01-0.20. The steel strip has a matrix consisting of tempered martensite and between 5 and 15 volume % austenite and a tensile strength (R.sub.m) of 1970-2300 MPa. The steel strip has a thickness of 0.07-3 mm and a width of 500 mm.

Methods of making bainitic steels may involve austenitizing a quantity of steel by exposing the quantity of steel to a first temperature. A composition of the quantity of steel may be configured to impede formation of non-bainite ferrite, pearlite, and Widmansttten ferrite. The quantity of steel may be heat-treated to form bainite by exposing the quantity of steel to a second, lower temperature. The second, lower temperature may be stabilized by exposing the quantity of steel to the second, lower temperature in the presence of a thermal ballast.

A number of variations may include a brake rotor having a surface oxide layer and methods of making the same.

A number of variations may include a brake rotor having a surface oxide layer and methods of making the same.

The present invention provides a method of heat treating a steel component including the sequential steps of: (a) carbonitriding the steel component; (b) quenching the steel component; (c) optionally tempering the steel component; and (d) ferritically nitrocarburizing the steel component.

The present invention provides a method of heat treating a steel component including the sequential steps of: (a) carbonitriding the steel component; (b) quenching the steel component; (c) optionally tempering the steel component; and (d) ferritically nitrocarburizing the steel component.