The invention discloses a molten AlSi alloy corrosion resistant composite coating and a preparation method and application thereof. The composite coating layer comprises an aluminized layer and a TiO.sub.2 thin film layer from the surface of a basal body to the external in sequence. The preparation method of the coating layer comprises the following steps: (S1) the surface of a Fe-based alloy is treated; and then, a solid powder permeating agent is adopted to permeate aluminum; (S2) sand-blasting the aluminized Fe-based alloy; (S3) the Fe-based alloy is washed and dried after sand blasting; and (S4) a TiO.sub.2 thin film layer is deposited on the surface of the dried aluminized Fe-based alloy by adopting an atomic layer vapor deposition method.

Powder compositions are described having, as constituents: an aluminum donor powder, an aluminum-containing activator powder comprising at least 50 wt. % KAlF.sub.4, and an inert filler powder. Related methods and coatings are also described.

Powder compositions are described having, as constituents: an aluminum donor powder, an aluminum-containing activator powder comprising at least 50 wt. % KAlF.sub.4, and an inert filler powder. Related methods and coatings are also described.

A method of using a ferrous structural component is described. The method comprises integrating a ferrous structural component into process equipment, where the ferrous structural component comprises an iron alloy body with a modified surface including an aluminized surface layer that comprises one or more iron aluminides. The modified surface of the iron alloy body is exposed to an oxidative environment, thereby forming, as part of the modified surface, a passivating layer comprising aluminum oxide on the aluminized surface layer. The modified surface is also exposed to a process fluid. The exposure to the oxidative environment occurs prior to and/or upon exposure of the modified surface to the process fluid. Due to protection afforded by the passivating layer, the modified surface resists fouling and corrosion while exposed to the process fluid, as exhibited by a substantial absence of carbonaceous deposits on the iron alloy body.

A method of using a ferrous structural component is described. The method comprises integrating a ferrous structural component into process equipment, where the ferrous structural component comprises an iron alloy body with a modified surface including an aluminized surface layer that comprises one or more iron aluminides. The modified surface of the iron alloy body is exposed to an oxidative environment, thereby forming, as part of the modified surface, a passivating layer comprising aluminum oxide on the aluminized surface layer. The modified surface is also exposed to a process fluid. The exposure to the oxidative environment occurs prior to and/or upon exposure of the modified surface to the process fluid. Due to protection afforded by the passivating layer, the modified surface resists fouling and corrosion while exposed to the process fluid, as exhibited by a substantial absence of carbonaceous deposits on the iron alloy body.

A method for converting an existing steam methane reformer (SMR) to produce hydrogen via ammonia cracking is provided. The method can include the steps of: providing the existing SMR, wherein the SMR was formerly used to produce hydrogen from a hydrocarbon feedstock; and improving the nitridation resistance of the inner surface of the equipment by adding a protective layer to an inner surface of equipment to be used in the existing SMR, wherein the equipment is selected from the group consisting of a catalyst tube, feed piping, a feed preheater, process gas heat exchangers, and combination thereof.

A method for converting an existing steam methane reformer (SMR) to produce hydrogen via ammonia cracking is provided. The method can include the steps of: providing the existing SMR, wherein the SMR was formerly used to produce hydrogen from a hydrocarbon feedstock; and improving the nitridation resistance of the inner surface of the equipment by adding a protective layer to an inner surface of equipment to be used in the existing SMR, wherein the equipment is selected from the group consisting of a catalyst tube, feed piping, a feed preheater, process gas heat exchangers, and combination thereof.

The invention relates to a method for coating a component, which is provided for the hot gas duct of a turbomachine, wherein the coating material is applied onto the uncoated component surface in the form of particles in mixture with a binding agent, and the component with the particle-treated binding agent thereupon then undergoes thermal treatment in such a way that the binding agent is released and the coating material remains on the component.

A component with a component (1) of low-alloy steel and/or heat-treatable steel is provided, wherein the component (1) is at least partially coated with an aluminum diffusion layer (10) and an aluminum oxide layer (14) is applied to the aluminum diffusion layer (10), wherein the layer thickness of the aluminum diffusion layer (10) is 1-200 ?m, wherein the aluminum diffusion layer (10) has an aluminum content, based on the total weight of the aluminum diffusion layer, of 10 wt. % above the aluminum content of the steel up to a maximum concentration, wherein the aluminum content in the aluminum diffusion layer (10) increases in the direction of the interface (12) between the aluminum diffusion layer (10) and the aluminum oxide layer (14) from 10% by weight up to the maximum concentration, and wherein the maximum concentration is 11-60% by weight.

Unique and improved chromizing processes are disclosed. The processes involve forming localized chromizing coatings onto selected regions of a substrate. The chromium diffusion coatings are locally applied to selected regions of substrates in a controlled manner, in comparison to conventional chromizing processes, and further in a manner that produces less material waste and does not require diffusion-stop-off masking. Prior to or after a localized slurry chromizing process of the present invention, a layer of a platinum-group-metal (PGM) is applied to produce a PGM-modified chromium diffusion coating onto selected regions of a substrate. A second coating can be selectively applied onto other regions of the substrate.