Methods for forming carbon-based lubricious and/or wear-protective films in situ on the surface of steel alloys are provided. The methods use chromium-containing steel alloys, molybdenum-containing steel alloys, and steel alloys that contain both copper and nickel. When such alloys are subjected to a rubbing motion in the presence of a hydrocarbon fluid, the chromium, molybdenum, copper, and nickel in the steel alloy catalyzes the formation of solid carbon-containing films that reduce the friction, wear, or both of the contacting surfaces.

A gas blower device for blowing gas onto a surface of a traveling strip includes a plenum in the form of a hollow box for containing gas and comprising two side surfaces, a back surface and a front surface opposite to the back surface. The front surface having a profile of convex type symmetry with respect to a mid-plane perpendicular to the plane of the strip, so that a middle ridge of the front surface is located at the smallest distance from the plane of the strip. The front surface further presenting multiple tubular nozzles protruding at the front surface and having a gas outlet orifice facing in use the traveling strip. All the outlet orifices are essentially in a plane parallel to the strip plane. The gas blower device further includes a gas intake tube for feeding the plenum with gas.

A gas blower device for blowing gas onto a surface of a traveling strip includes a plenum in the form of a hollow box for containing gas and comprising two side surfaces, a back surface and a front surface opposite to the back surface. The front surface having a profile of convex type symmetry with respect to a mid-plane perpendicular to the plane of the strip, so that a middle ridge of the front surface is located at the smallest distance from the plane of the strip. The front surface further presenting multiple tubular nozzles protruding at the front surface and having a gas outlet orifice facing in use the traveling strip. All the outlet orifices are essentially in a plane parallel to the strip plane. The gas blower device further includes a gas intake tube for feeding the plenum with gas.

A method of making a forged, martensitic, stainless steel alloy is provided. The alloy is a forged preform of martensitic, pitting corrosion resistant stainless steel alloy comprising, by weight: 12.0 to 16.0 percent chromium; greater than 16.0 to 20.0 percent cobalt, 6.0 to 8.0 percent molybdenum, 1.0 to 3.0 percent nickel, 0.02 to 0.04 percent carbon; and the balance iron and incidental impurities. The alloy has a microstructure that comprises a retained austenite phase less than or equal to 2 percent by volume of the microstructure. The method heats the preform to a solutionizing temperature to form a solutionized microstructure. The preform is cooled with a liquid to room temperature at a rate of no less than 0.25° C./sec. to prevent formation of sigma phase. The preform is immersed in a cryo-liquid to transform the retained austenite phase in the microstructure to martensite. The preform is heated to a temperature of less than 600° F. for a time sufficient to form a tempered forged preform.

A method of making a forged, martensitic, stainless steel alloy is provided. The alloy is a forged preform of martensitic, pitting corrosion resistant stainless steel alloy comprising, by weight: 12.0 to 16.0 percent chromium; greater than 16.0 to 20.0 percent cobalt, 6.0 to 8.0 percent molybdenum, 1.0 to 3.0 percent nickel, 0.02 to 0.04 percent carbon; and the balance iron and incidental impurities. The alloy has a microstructure that comprises a retained austenite phase less than or equal to 2 percent by volume of the microstructure. The method heats the preform to a solutionizing temperature to form a solutionized microstructure. The preform is cooled with a liquid to room temperature at a rate of no less than 0.25° C./sec. to prevent formation of sigma phase. The preform is immersed in a cryo-liquid to transform the retained austenite phase in the microstructure to martensite. The preform is heated to a temperature of less than 600° F. for a time sufficient to form a tempered forged preform.

A hood-type annealing furnace has a base, which has a site on which a batch of a annealing material can be arranged. The annealing material arranged on the site can be covered by a protective hood, which forms an annealing space enclosed by the protective hood and the site. The protective hood can be covered by a heating hood, thereby forming an intermediate space arranged between the heating hood and the protective hood and bounded at the bottom by the base. A cooling gas system is communicably connected or connectable to the intermediate space. The cooling gas system is communicably connected or connectable to the intermediate space, to a cooling gas outlet formed on the base and communicably connected to the intermediate space, and at least one cooling gas inlet formed on the base and communicably connected to the intermediate space.

The present invention relates to a process for cooling a metal component, the process comprising the step of cooling said component in a confined space, said cooling involving cooling by means of a gas, the gas being cooled by heat exchange with a cooling surface of a heat sink inside said confined space, wherein a low frequency sound wave is provided into said confined space in order to improve heat exchange both between the gas and a cooling surface of the at least one heat sink, and between the gas and the metal component, characterised in that the cooling gas comprises at least one protective inert gas. The invention further relates to an apparatus for performing the process.

The present disclosure provides a method for preparing a steel alloy sheet to enhance flatness. The method includes, inter alia, heating a steel alloy material to a first temperature that is greater than a full-austenitization point for the steel alloy material; holding steel alloy material at the first temperature for a period greater than or equal to about 1 second to less than or equal to about 10,000 seconds to from a precursor steel sheet; air quenching the precursor steel sheet to a second temperature that is less than the first temperature and greater than martensitic transformation starting temperature for the steel alloy material; and cooling the precursor steel sheet to room temperature to prepare the steel alloy sheet. The steel alloy material includes greater than or equal to about 0.5 wt. % to less than or equal to about 6 wt. % of chromium.

The present disclosure provides a method for preparing a steel alloy sheet to enhance flatness. The method includes, inter alia, heating a steel alloy material to a first temperature that is greater than a full-austenitization point for the steel alloy material; holding steel alloy material at the first temperature for a period greater than or equal to about 1 second to less than or equal to about 10,000 seconds to from a precursor steel sheet; air quenching the precursor steel sheet to a second temperature that is less than the first temperature and greater than martensitic transformation starting temperature for the steel alloy material; and cooling the precursor steel sheet to room temperature to prepare the steel alloy sheet. The steel alloy material includes greater than or equal to about 0.5 wt. % to less than or equal to about 6 wt. % of chromium.

A bearing assembly, particularly refrigerant lubricated bearing assembly, having at least an inner ring and an outer ring, which are rotatable to each other. At least one bearing ring is made from a nitrogen-alloyed stainless steel having a nitrogen (N) content of more than 0.6 wt.-%. A method for manufacturing such a bearing ring is also provided.