A nickel-based alloy is coated with a silicate based nickel aluminide slurry diffusion coating.

Provided is a steel for nitrocarburizing that ensures mechanical workability before nitrocarburizing treatment. A steel for nitrocarburizing comprises: a chemical composition containing, in mass %, C: ≥0.02% and <0.15%, Si: ≤0.30%, Mn: 1.5-2.5%, P: ≤0.025%, S: ≤0.06%, Cr: 0.5-2.0%, Mo: 0.005-0.2%, V: 0.02-0.20%, Nb: 0.003-0.20%, Al: >0.020% and ≤1.0%, Ti: >0.0050% and ≤0.015%, N: ≤0.0200%, Sb: 0.0030-0.010%, with a balance being Fe and inevitable impurities, satisfying Expression (1) or (2); and a steel microstructure where an area ratio of bainite phase is >50%, a prior austenite grain size is ≤100 μm, ≥300/μm.sup.2 Ti precipitates with an equivalent circular particle size of ≤30 nm disperse, Sb segregates to prior austenite grain boundaries.

Provided is a steel for nitrocarburizing that ensures mechanical workability before nitrocarburizing treatment. A steel for nitrocarburizing comprises: a chemical composition containing, in mass %, C: ≥0.02% and <0.15%, Si: ≤0.30%, Mn: 1.5-2.5%, P: ≤0.025%, S: ≤0.06%, Cr: 0.5-2.0%, Mo: 0.005-0.2%, V: 0.02-0.20%, Nb: 0.003-0.20%, Al: >0.020% and ≤1.0%, Ti: >0.0050% and ≤0.015%, N: ≤0.0200%, Sb: 0.0030-0.010%, with a balance being Fe and inevitable impurities, satisfying Expression (1) or (2); and a steel microstructure where an area ratio of bainite phase is >50%, a prior austenite grain size is ≤100 μm, ≥300/μm.sup.2 Ti precipitates with an equivalent circular particle size of ≤30 nm disperse, Sb segregates to prior austenite grain boundaries.

A method of coating an alloy substrate includes providing an alloy substrate that includes less than 0.3 wt. % of diffusible elements; introducing one or more diffusible elements into the alloy substrate to thereby form a diffusible-element-containing alloy substrate; and introducing the diffusible-element-containing alloy substrate to a material reactive with the one or more diffusible elements.

A lining structure for a refractory vessel contains a first layer containing refractory material; a second layer, in communication with and parallel to the first layer, containing a metal layer or component; and a third layer, in communication with and parallel to the second layer, containing refractory material. The metal component in the second layer contains filled transverse passages, between the surface of the second layer in contact with the first layer and the surface of the second layer in contact with the third layer, producing support structures to maintain the structural integrity of the refractory vessel in use.

A lining structure for a refractory vessel contains a first layer containing refractory material; a second layer, in communication with and parallel to the first layer, containing a metal layer or component; and a third layer, in communication with and parallel to the second layer, containing refractory material. The metal component in the second layer contains filled transverse passages, between the surface of the second layer in contact with the first layer and the surface of the second layer in contact with the third layer, producing support structures to maintain the structural integrity of the refractory vessel in use.

Composite structures having a reinforced material intermingled with a substrate wherein the reinforced material includes titanium monoboride, titanium diboride, or a combination thereof.

Methods of forming an environmental barrier coating are disclosed. A method includes disposing a powder-based coating on a substrate, heat-treating the powder-based coating at a temperature greater than 800 C. and less than 1200 C. to form a porous coating that includes surface-connected pores, infiltrating at least some of the surface-connected pores of the porous coating with an infiltrant material to form an infiltrated coating, and sintering the infiltrated coating at a temperature greater than 1200 C. and less than 1500 C. to form the environmental barrier coating on the substrate.

Methods of forming an environmental barrier coating are disclosed. A method includes disposing a powder-based coating on a substrate, heat-treating the powder-based coating at a temperature greater than 800 C. and less than 1200 C. to form a porous coating that includes surface-connected pores, infiltrating at least some of the surface-connected pores of the porous coating with an infiltrant material to form an infiltrated coating, and sintering the infiltrated coating at a temperature greater than 1200 C. and less than 1500 C. to form the environmental barrier coating on the substrate.

At least a part of a burner for a catalytic reactor is coated with a silicate based nickel aluminide slurry diffusion coating.