A method for applying a composition to a substrate, and a downhole component, of which the method includes thermal spraying a layer of the composition onto the substrate, the substrate being provided by a downhole component, the layer resulting from the thermal spraying having a thickness of at least about 0.10 inches and being configured to remain bonded to the downhole component when used downhole in a well, the composition being chromium-free.

A method for applying a composition to a substrate, and a downhole component, of which the method includes thermal spraying a layer of the composition onto the substrate, the substrate being provided by a downhole component, the layer resulting from the thermal spraying having a thickness of at least about 0.10 inches and being configured to remain bonded to the downhole component when used downhole in a well, the composition being chromium-free.

A precipitation-hardened stainless steel alloy is disclosed including, by weight: 14.0-16.0% Cr; 6.0-7.0% Ni; 1.25-1.75% Cu; 0.5-1.0% Mo; 0.40-0.85% Nb; 0.025-0.05% C; up to 1.0% Mn; up to 1.0% Si; up to 0.1% V; up to 0.1% Co; up to 0.1% Sn; up to 0.02% N; up to 0.025% P; up to 0.05% Al; up to 0.008% S; up to 0.005% Ag; up to 0.005% Pb; up to 0.1% As; up to 0.01% Sb; and a balance of Fe. The alloy has a ratio of Nb:(C+N) of at least 15:1.

A precipitation-hardened stainless steel alloy is disclosed including, by weight: 14.0-16.0% Cr; 6.0-7.0% Ni; 1.25-1.75% Cu; 0.5-1.0% Mo; 0.40-0.85% Nb; 0.025-0.05% C; up to 1.0% Mn; up to 1.0% Si; up to 0.1% V; up to 0.1% Co; up to 0.1% Sn; up to 0.02% N; up to 0.025% P; up to 0.05% Al; up to 0.008% S; up to 0.005% Ag; up to 0.005% Pb; up to 0.1% As; up to 0.01% Sb; and a balance of Fe. The alloy has a ratio of Nb:(C+N) of at least 15:1.

A bar-shaped stainless steel product contains, by mass %, 0.001 to 0.030% of C, 0.01 to 4.00% of Si, 0.01 to 2.00% of Mn, 0.01 to 4.00% of Ni, 6.0 to 35.0% of Cr, 0.01 to 5.00% of Mo, 0.01 to 2.00% of Cu, and 0.001 to 0.050% of N. In the product, an F value is 20 or less, a rolling-direction-crystal-orientation RD//<100> fraction is 0.05 or more, and preferably a rolling-direction-crystal-orientation RD//<334> fraction is 0.2 or less. The above RD//<100> fraction means an area ratio of crystal having 25 degrees or less of an orientation difference between a <100> orientation and a rolling direction, and the above RD//<334> fraction means an area ratio of crystal having 10 degrees or less of an orientation difference between a <334> orientation and a rolling direction. F value=700C+800N+20Ni+10Cu+10Mn−6.2Cr−9.2Si−9.3Mo−74.4Ti−37.2A1−3.1Nb+63.2

A bar-shaped stainless steel product contains, by mass %, 0.001 to 0.030% of C, 0.01 to 4.00% of Si, 0.01 to 2.00% of Mn, 0.01 to 4.00% of Ni, 6.0 to 35.0% of Cr, 0.01 to 5.00% of Mo, 0.01 to 2.00% of Cu, and 0.001 to 0.050% of N. In the product, an F value is 20 or less, a rolling-direction-crystal-orientation RD//<100> fraction is 0.05 or more, and preferably a rolling-direction-crystal-orientation RD//<334> fraction is 0.2 or less. The above RD//<100> fraction means an area ratio of crystal having 25 degrees or less of an orientation difference between a <100> orientation and a rolling direction, and the above RD//<334> fraction means an area ratio of crystal having 10 degrees or less of an orientation difference between a <334> orientation and a rolling direction. F value=700C+800N+20Ni+10Cu+10Mn−6.2Cr−9.2Si−9.3Mo−74.4Ti−37.2A1−3.1Nb+63.2

The present disclosure relates to an austenitic stainless alloy comprising in weight % (wt %): C less than 0.03; Si less than 1.0; Mn less than or equal to 1.2; Cr 26.0 to 30.0; Ni 29.0 to 37.0; Mo 6.1 to 7.1 or (Mo+W/2) 6.1 to 7.1; N 0.25 to 0.36; P less than or equal to 0.04; S less than or equal to 0.03; Cu less than or equal to 0.4; balance Fe and unavoidable impurities and to the use thereof and to products made thereof. Thus, the austenitic stainless alloy comprises a low content of manganese in combination with a high content of nitrogen. The present disclosure also relates to the use of said austenitic stainless alloy, especially in highly corrosive environments and to products made of thereof.

The invention relates to a steel for structural components used at elevated temperatures. The steel comprises the following main components (in wt. %): Cr 8.0-14.0 Ni 4.0-14.0 Al 2.5-5.0 C 0.003-0.3 N≤0.06 Mo+W≤4.0 at least one of: Nb 0.01-1.0 Ta 0.01-1.0 Ti 0.01-1.0 Zr 0.01-1.0 Hf 0.01-1.0 Y 0.05-1.0 balance optional elements, Fe and impurities; and the steel composition fulfilling the following condition: Cr(eq)+Ni(eq)≤30; where Cr(eq)=Cr+2Al+1.5(Si+Nb+Ti)+Mo+0.5W; and Ni(eq)=Ni+10(C+N)+0.5(Mn+Cu+Co).

Disclosed is an ultrahigh-strength maraging stainless steel with multiphase strengthening and a preparation method thereof. The stainless steel has a composition in mass percentage as follows: 1.0-5.0% of Co, 6.0-10.0% of Ni, 11.0-17.0% of Cr, 0.3-2.0% of Ti, 3.0-7.0% of Mo, 0.08-1.0% of Mn, 0.08-0.5% of Si, 0.02% or less of C, 0.003% or less of P, 0.003% or less of S, and Fe as a balance.

Disclosed is an ultrahigh-strength maraging stainless steel with multiphase strengthening and a preparation method thereof. The stainless steel has a composition in mass percentage as follows: 1.0-5.0% of Co, 6.0-10.0% of Ni, 11.0-17.0% of Cr, 0.3-2.0% of Ti, 3.0-7.0% of Mo, 0.08-1.0% of Mn, 0.08-0.5% of Si, 0.02% or less of C, 0.003% or less of P, 0.003% or less of S, and Fe as a balance.