A method for repairing a damaged portion of a steel member that includes at least one of a coating and a plating. The method includes applying to the damaged portion of the steel member a coating composition to produce a repair coating. The coating composition includes nickel, chromium, and carbon.

Methods and compositions are provided for improving metal dusting corrosion, abrasion resistance and/or erosion resistance for various materials, preferably for applications relating to high-temperature reactors, including dense fluidized bed reactor components. In particular, cermets comprising (a) at least one ceramic phase selected from the group consisting of metal carbides, metal nitrides, metal borides, metal oxides, metal carbonitrides, and mixtures of thereof and (b) at least one metal alloy binder phase are provided. Ceramic phase materials include chromium carbide (Cr.sub.23C.sub.6). Metal alloy binder phase materials include β-NiAl intermetallic alloys and Ni.sub.3Sn.sub.2 intermetallic alloys, as well as alloys that contain α-Cr and/or γ′-Ni.sub.3Al hard phases. Preferably, bimetallic materials are provided when the cermet compositions are applied using a laser, e.g., a laser cladding method such as high power direct diode (HPDD) laser, or by plasma-based methods such as plasma transfer arc (PTA) welding and powder plasma welding (PPW).

An austenitic alloy based on nickel and having a high chromium content, intended to be used at a given operating temperature between 900° C. and 1150° C., comprises the following elements by mass percentage: chromium between 40% and 45%; iron between 10% and 14%; carbon between 0.4% and 0.6%; titanium between 0.05% and 0.2%; niobium between 0.5% and 1.5%; at least one reactive element, selected from rare earths or hafnium, between 0.002% and 0.1%; silicon between 0% and 1%; manganese between 0% and 0.5%; nickel to balance the alloy elements. In addition, the alloy has a molar fraction of more than 0.1% of secondary carbo-nitrides rich in niobium and/or titanium, after the operating temperature has been applied thereto. The disclosure also relates to a method for designing such an alloy and to a method for validating such an alloy.

A method of ion-plasma application of corrosion-resistant film coatings on articles made from zirconium alloys includes placing articles in a planetary carousel mechanism, heating the articles, and ion-beam etching and surface activation of the articles using water-cooled unbalanced magnetrons. In addition, the surface of the articles is activated using an ion source which generates gas ions with an accelerating voltage of up to 5000 V and with feeding of a bias voltage to the articles. The coating is applied by using unbalanced and balanced magnetrons simultaneously with a residual induction of the magnetic field from 0.03 T to 0.1 T. The coating is applied to articles which are made from zirconium alloys and are placed vertically in a planetary carousel mechanism. The articles are heated in the coating application process to a temperature of 150-600° C., wherein the heaters are accommodated along the entire length of the articles. This produces corrosion-resistant film coatings of uniform thickness along the outer surface of articles made from zirconium alloys and raises productivity due to an increase in the discharge power density of magnetrons.

A method of ion-plasma application of corrosion-resistant film coatings on articles made from zirconium alloys includes placing articles in a planetary carousel mechanism, heating the articles, and ion-beam etching and surface activation of the articles using water-cooled unbalanced magnetrons. In addition, the surface of the articles is activated using an ion source which generates gas ions with an accelerating voltage of up to 5000 V and with feeding of a bias voltage to the articles. The coating is applied by using unbalanced and balanced magnetrons simultaneously with a residual induction of the magnetic field from 0.03 T to 0.1 T. The coating is applied to articles which are made from zirconium alloys and are placed vertically in a planetary carousel mechanism. The articles are heated in the coating application process to a temperature of 150-600° C., wherein the heaters are accommodated along the entire length of the articles. This produces corrosion-resistant film coatings of uniform thickness along the outer surface of articles made from zirconium alloys and raises productivity due to an increase in the discharge power density of magnetrons.

A high hardness and temperature-resistant alloy is disclosed, and comprises 10-40 atomic percent Co, 30-56 atomic percent Cr, 10-40 atomic percent Ni, 6-13 atomic percent C, 0-8 atomic percent Mo, and 0-8 atomic percent W. Moreover, the elemental composition of the high hardness and temperature-resistant alloy can further comprise at least one additive element, such as Pb, Sn, Ge, Si, Zn, Sb, P, B, Mg, Mn, V, Nb, Ti, Zr, Y, La, Ce, Al, Ta, Cu, and Fe. Experimental data reveal that, the high hardness and temperature-resistant alloy can still show a property of hardness greater than HV100 in 900 degrees Celsius. Therefore, experimental data have proved that the high hardness and temperature-resistant alloy has a significant potential for applications in the manufacture of hot working die metals, components (e.g., turbine blade) for high temperature applications, and devices (e.g., aeroengine) for high temperature applications.

A high hardness and temperature-resistant alloy is disclosed, and comprises 10-40 atomic percent Co, 30-56 atomic percent Cr, 10-40 atomic percent Ni, 6-13 atomic percent C, 0-8 atomic percent Mo, and 0-8 atomic percent W. Moreover, the elemental composition of the high hardness and temperature-resistant alloy can further comprise at least one additive element, such as Pb, Sn, Ge, Si, Zn, Sb, P, B, Mg, Mn, V, Nb, Ti, Zr, Y, La, Ce, Al, Ta, Cu, and Fe. Experimental data reveal that, the high hardness and temperature-resistant alloy can still show a property of hardness greater than HV100 in 900 degrees Celsius. Therefore, experimental data have proved that the high hardness and temperature-resistant alloy has a significant potential for applications in the manufacture of hot working die metals, components (e.g., turbine blade) for high temperature applications, and devices (e.g., aeroengine) for high temperature applications.

Provided in one embodiment is a method, comprising: sintering a plurality of nanocrystalline particulates to form a nanocrystalline alloy, wherein at least some of the nanocrystalline particulates may include a non-equilibrium phase comprising a first metal material and a second metal material, and the first metal material may be soluble in the second metal material. The sintered nanocrystalline alloy may comprise a bulk nanocrystalline alloy.

Provided in one embodiment is a method, comprising: sintering a plurality of nanocrystalline particulates to form a nanocrystalline alloy, wherein at least some of the nanocrystalline particulates may include a non-equilibrium phase comprising a first metal material and a second metal material, and the first metal material may be soluble in the second metal material. The sintered nanocrystalline alloy may comprise a bulk nanocrystalline alloy.

The purpose of the present invention is to provide an alloy product which has both of high corrosion resistance enough to withstand severe corrosive/high-temperature environments and mechanical properties equivalent to or better than those of stainless steel, and which can be produced at lower cost than a Ni-based alloy. The Cr—Fe—Ni-based alloy product of the present invention is a product produced using a Cr—Fe—Ni-based alloy containing Cr as a largest-content component, wherein the product has such a microstructure that a dual-phase structure having a ferrite phase and an austenite phase coexisting therein serves as a matrix phase and an L1.sub.2-type Ni-based intermetallic compound phase is dispersed and precipitated in the austenite phase.