A substrate steel of the comprising from 0.01 to 0.60 wt. % of La, from 0.0 to 0.65 wt. % of Ce; from 0.06 to 1.8 wt. % of Nb up to 2.5 wt. % of one or more trace elements and carbon and silicon may be treated in an oxidizing atmosphere to product a coke resistant surface coating of MnCr.sub.2O.sub.4 having a thickness up to 5 microns.

A nickel-base alloy welding material according to an embodiment comprises: Cr (chromium) larger than 30.0% and less than or equal to 36.0% by mass; C (carbon) less than or equal to 0.050% by mass; Fe (iron) larger than or equal to 1.00% and less than or equal to 3.00% by mass; Si (silicon) less than or equal to 0.50% by mass; Nb (niobium)+Ta (tantalum) less than or equal to 3.00% by mass; Ti (titanium) less than or equal to 0.70% by mass; Mn (manganese) larger than or equal to 0.10% and less than or equal to 3.50% by mass; Cu (copper) less than or equal to 0.5% by mass, and a remainder is Ni and unavoidable impurities.

An objective of the invention to provide an alloy article that exhibits even better mechanical properties and/or even higher corrosion resistance than conventional high entropy articles without sacrificing the attractive properties thereof, a product formed of the alloy article, and a fluid machine having the product. An alloy article according to the invention has a predetermined chemical composition comprising: Co, Cr, Fe, Ni and Ti, each within a range of 5 atomic % or more and 35 atomic % or less; Mo within a range of more than 0 atomic % and less than 8 atomic %; an element with a larger atomic radius than the atomic radiuses of Co, Cr, Fe and Ni within a range of more than 0 atomic % and 4 atomic % or less; and a balance of inevitable impurities.

A heterogeneous composition is disclosed, including an alloy mixture and a ceramic additive. The alloy mixture includes a first alloy having a first melting point of at least a first threshold temperature, and a second alloy having a second melting point of less than a second threshold temperature. The second threshold temperature is lower than the first threshold temperature. The first alloy, the second alloy, and the ceramic additive are intermixed with one another as distinct phases. An article is disclosed including a first portion including a material composition, and a second portion including the heterogeneous composition. A method for forming the article is disclosing, including applying the second portion to the first portion.

A nickel-chromium casting alloy comprising, in weight percent, up to 0.8% of carbon, up to 1% of silicon, up to 0.2% of manganese, 15 to 40% of chromium, 0.5 to 13% of iron, 1.5 to 7% of aluminum, up to 2.5% of niobium, up to 1.5% of titanium, 0.01 to 0.4% of zirconium, up to 0.06% of nitrogen, up to 12% of cobalt, up to 5% of molybdenum, up to 6% of tungsten and from 0.01 to 0.1% of yttrium, remainder nickel, has a high resistance to carburization and oxidation even at temperatures of over 1130 C. in a carburizing and oxidizing atmosphere, as well as a high thermal stability, in particular creep rupture strength.

An Ni-based alloy solid wire for welding has a composition comprising specific amounts of Cr, Ti, Nb, C, S, Mn and Fe, where Mo+W, P, Si, Al, Ca, B, Mg, Zr, Co, O, H, and N are controlled to specific amounts, ([Ti]+[Nb])/[C] is 80 to 150, and the balance is Ni and inevitable impurities. [Ti], [Nb], and [C] represent the contents of Ti, Nb, and C (mass %), respectively.

The present invention relates to alloys used to prepare steel pipes i.e. tubes for use in chemical engineering applications. In particular, the invention relates to low carbon aluminium steel alloys and pipes made from such alloys. They may be used in plant such as ethylene cracker furnaces that need to be able to withstand elevated temperatures oxidation and carburisation for extended periods of time, the alloy been able to develop a pure, stable and continuous aluminium oxide layer on it surface when in service which is protective and anti-coking

An Ni-based alloy pipe for nuclear power has a chemical composition consisting of, in mass percent: C: 0.015 to 0.030%, Si: 0.10 to 0.50%, Mn: 0.10 to 0.50%, P: 0.040% or less, S: 0.015% or less, Cu: 0.01 to 0.20%, Ni: 50.0 to 65.0%, Cr: 19.0 to 35.0%, Mo: 0 to 0.40%, Co: 0.040% or less, Al: 0.30% or less, N: 0.010 to 0.080%, Ti: 0.020 to 0.180%, Zr: 0.010% or less, and Nb: 0.060% or less, the balance: Fe and impurities, and satisfying [(NTi14/48)d.sup.34000] in relation to an average grain diameter, wherein a standard deviation of grain diameters is 20 m or less, and a hardness of insides of grains is 180 HV or more.

A method of welding using a weld filler additive and a weld filler additive are provided. The method includes the step of welding the component with a filler additive comprising a sufficient amount of each of W, Co, Cr, Al, Ti, Mo, Fe, B, C, Nb, and Ni, the component including a hard-to-weld base alloy. The method further includes the step of forming an easy-to-weld target alloy on a surface of the component from the welding.

The present invention provides a Co-free heat-resistant alloy for a hearth metal member that has properties superior to or equal to those of Co-containing heat resistant steel. The heat-resistant alloy for a hearth metal member according to the present invention is a heat-resistant alloy used in a hearth metal member of a steel heating furnace, the heat resistant alloy containing: 0.05% to 0.5% of C; more than 0% and 0.95% or less of Si, where 0.05% C+Si1.0%; more than 0% and 1.0% or less of Mn; 40% to 50% of Ni; 25% to 35% of Cr; 1.0% to 3.0% of W; and 10% or more of Fe and inevitable impurities as the balance, with all percentages being in mass %. The heat-resistant alloy for a hearth metal member may further contain 0.05% to 0.5% of Ti and/or 0.02% to 1.0% of Zr, with all percentages being in mass %