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.

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.

The present invention relates to a soft magnetic alloy containing: Ni, and at least one element selected from the group consisting of Al, Si and V, with the balance being Fe and inevitable impurities, in which, when the content of Ni and the total content of Al, Si and V are expressed by [Ni] and [M], respectively in mass %, and a relationship between [Ni] and [M] is plotted, the coordinate ([Ni], [M]) is present in a region surrounded by the straight lines A, B, C, D, and E.

The present invention relates to a soft magnetic alloy containing: Ni, and at least one element selected from the group consisting of Al, Si and V, with the balance being Fe and inevitable impurities, in which, when the content of Ni and the total content of Al, Si and V are expressed by [Ni] and [M], respectively in mass %, and a relationship between [Ni] and [M] is plotted, the coordinate ([Ni], [M]) is present in a region surrounded by the straight lines A, B, C, D, and E.

This disclosure is related to high yield strength steel where yield strength can be increased without significantly affecting ultimate tensile strength (UTS) and in some cases, higher yield strength can be obtained without significant decrease in ultimate tensile strength and total elongation.

This disclosure is related to high yield strength steel where yield strength can be increased without significantly affecting ultimate tensile strength (UTS) and in some cases, higher yield strength can be obtained without significant decrease in ultimate tensile strength and total elongation.

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.