A Ni—Cr—Fe alloy with improved resistance to stress corrosion cracking in nuclear environments, the alloy comprising 23-28 wt % Cr, 25-35 wt % Ni, <0.03 wt % C, <0.70 wt % Si, <1.0 wt % Mn, <0.015 wt % S, >0.35 wt % Ti, 0.15-0.45 wt % Al, <0.75 wt % Cu, and balance Fe and incidental impurities. The alloy may be used in steam generator tubing of a nuclear reactor. A method of producing an article includes: providing the alloy as disclosed herein; forming the alloy into the article by cold working the alloy to 20%; and heat treating the article.

A Ni—Cr—Fe alloy with improved resistance to stress corrosion cracking in nuclear environments, the alloy comprising 23-28 wt % Cr, 25-35 wt % Ni, <0.03 wt % C, <0.70 wt % Si, <1.0 wt % Mn, <0.015 wt % S, >0.35 wt % Ti, 0.15-0.45 wt % Al, <0.75 wt % Cu, and balance Fe and incidental impurities. The alloy may be used in steam generator tubing of a nuclear reactor. A method of producing an article includes: providing the alloy as disclosed herein; forming the alloy into the article by cold working the alloy to 20%; and heat treating the article.

A bolt of the present invention has a composition comprising: 0.50 mass % or greater and 0.65 mass % or less of carbon (C), 1.5 mass % or greater and 2.5 mass % or less of silicon (Si), 1.0 mass % or greater and 2.0 mass % or less of chromium (Cr), 0.2 mass % or greater and 1.0 mass % or less of manganese (Mn), 1.5 mass % or greater and 5.0 mass % or less of molybdenum (Mo), wherein a total amount of phosphorous (P) and sulfur (S) as impurities is 0.03 mass % or less, the remaining is iron (Fe), and the bolt comprises an iron based oxide film with a film thickness of 3 μm or greater and 20 μm or less on the surface thereof. The bolt has excellent delayed fracture resistance and reliably provides a fastening axial force.

A bolt of the present invention has a composition comprising: 0.50 mass % or greater and 0.65 mass % or less of carbon (C), 1.5 mass % or greater and 2.5 mass % or less of silicon (Si), 1.0 mass % or greater and 2.0 mass % or less of chromium (Cr), 0.2 mass % or greater and 1.0 mass % or less of manganese (Mn), 1.5 mass % or greater and 5.0 mass % or less of molybdenum (Mo), wherein a total amount of phosphorous (P) and sulfur (S) as impurities is 0.03 mass % or less, the remaining is iron (Fe), and the bolt comprises an iron based oxide film with a film thickness of 3 μm or greater and 20 μm or less on the surface thereof. The bolt has excellent delayed fracture resistance and reliably provides a fastening axial force.

A metal powder for powder metallurgy contains Fe as a principal component, Ni in a proportion of 5 mass % or more and 20 mass % or less, Si in a proportion of 0.3 mass % or more and 5 mass % or less, and C in a proportion of 0.005 mass % or more and 0.3 mass % or less, and when one element selected from the group consisting of Ti, V, Y, Zr, Nb, Hf, and Ta is defined as a first element, and one element selected from the group and having a higher group number in the periodic table than that of the first element or having the same group number in the periodic table as that of the first element and a higher period number in the periodic table than that of the first element is defined as a second element.

The present invention relates to material utilized for heavy construction machinery, vehicle frames, reinforcing members, and the like, and more specifically to a high-strength steel sheet having excellent impact resistance and a method for manufacturing same.

The present invention relates to material utilized for heavy construction machinery, vehicle frames, reinforcing members, and the like, and more specifically to a high-strength steel sheet having excellent impact resistance and a method for manufacturing same.

An inoculant for the manufacture of cast iron with spheroidal graphite is disclosed, the inoculant has a particulate ferrosilicon alloy having between 40 and 80% by weight of Si, 0.02-8% by weight of Ca; 0-5% by weight of Sr; 0-12% by weight of Ba; 0-10% by weight of rare earth metal; 0-5% by weight of Mg; 0.05-5% by weight of Al; 0-10% by weight of Mn; 0-10% by weight of Ti; 0-10% by weight of Zr; the balance being Fe and incidental impurities in the ordinary amount, wherein the inoculant additionally contains, by weight, based on the total weight of inoculant: 0.1 to 15% by weight of particulate rare earth metal oxide(s) and at least one of from 0.1 to 15% of particulate Bi.sub.2O.sub.3, and/or from 0.1 to 15% of particulate Bi.sub.2S.sub.3, and/or from 0.1 to 15% of particulate Sb.sub.2O.sub.3, and/or from 0.1 to 15% of particulate Sb.sub.2S.sub.3, and/or from 0.1 to 5% of one of more of particulate Fe.sub.3O.sub.4, Fe.sub.2O.sub.3, FeO, or a mixture thereof, and/or from 0.1 to 5% of one of more of particulate FeS, FeS.sub.2, Fe.sub.3S.sub.4, or a mixture thereof, a method for producing such inoculant and use of such inoculant.

An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4≤0.4*Cr+Si≤3.2 (wherein element symbols denote measurements of respective element contents by weight %).

An aspect of the present invention relates to a cold-rolled steel plate for hot forming, which is excellent in corrosion-resistance and spot-weldability, contains, by weight %, C: 0.1-0.4%, Si: 0.5-2.0%, Mn: 0.01-4.0%, Al: 0.001-0.4%, P: 0.001-0.05%, S: 0.0001-0.02%, Cr: 0.5% to less than 3.0%, N: 0.001-0.02%, and a balance of Fe and inevitable impurities, satisfying formula (1) below, and includes an Si amorphous oxidation layer continuously or discontinuously formed at a thickness of 1 nm-100 nm on the surface thereof. Formula (1): 1.4≤0.4*Cr+Si≤3.2 (wherein element symbols denote measurements of respective element contents by weight %).