Abstract: In order to provide rolling bearings of high performance using case hardened stainless steels that are superior to the conventional martensite base stainless steels in terms of corrosion resistance, rolling fatigue strength and wear resistance and which also have high core toughness, at least one member of the rolling bearing selected from among the inner race, the outer race and the rolling elements is made of an alloy steel consisting essentially of less than 0.5 wt % C, 8.0 to 20.0 wt % Cr, 0.1 to 1.5 wt % Mn, 0.1 to 2.0 wt % Si and the balance of Fe and incidental impurity elements; the relationship between the C and Cr contents satisfies 0.04 Cr (wt %)-0.39.ltoreq.C (wt %).ltoreq.-0.05 Cr (wt %)+1.41; the bearing also has a surface layer that is formed by nitriding or carbonitriding at a temperature below Ac.sub.1, subsequent heating at a temperature of 900.degree. to 1,200.degree. C., hardening, a subzero treatment and tempering.

Abstract: A rolling bearing has components of an inner race, an outer race and rolling elements, one of the components being formed of an alloy steel containing 0.1-1.0 wt % of C, 0.1-1.5 wt % of Si, 0.1-1.5 wt % of Mn and 0.1-3.0 wt % of Cr, the alloy steel being carbonitrided and then ground to form a surface layer having a carbon and a nitrogen concentration of 0.6-1.5 wt % and 0.05-0.9 wt %, respectively. The surface layer has an appropriate amount of retained austenite .gamma..sub.R and is sufficiently hard to insure long life even under lubrication in the presence of foreign matter. By optimizing the choice of constituent materials, processing methods and heat treatments for each of the rolling elements and the inner and outer races, rolling bearings that have high performance can be produced at low cost.

Abstract: One of component parts of an inner race, an outer race and rolling elements of a rolling bearing is composed of a bearing material that is prepared by working a high-speed steel, carburizing or carbonitriding the wrought steel in a temperature range from 800.degree. C. to less than 1200.degree. C. and subsequently hardening and tempering the carburized or carbonitrided steel, the steel composing of 0.2 wt %.ltoreq.C.ltoreq.2.3 wt %, Si.ltoreq.1.0 wt %, Mn.ltoreq.1.0 wt %, 2.0 wt %.ltoreq.Cr.ltoreq.7.0 wt %, 1.5 wt %.ltoreq.W.ltoreq.22.0 wt %, Mo.ltoreq.10.0 wt %, 0.5.ltoreq.V.ltoreq.6.0 wt %, Co.ltoreq.18.0 wt %, the balance Fe and incidental impurities. By carburizing or carbonitriding the steel at low temperatures less than 1,200.degree. C.

Abstract: A method of producing a hot-dip galvannealed steel sheet from a very-low-carbon cold-rolled steel sheet containing not less than 0.01 wt % but not more than 0.1 wt % of Ti, by subjecting the cold rolled steel sheet to a process conducted in a continuous hot-dip galvanizing system including a heat treatment, hot-dip galvanizing and a subsequent galvannealing. The method is characterized by the steps of: subjecting the cold-rolled steel sheet to a degreasing and an acid cleaning; subjecting the degreased and acid-cleaned steel sheet to a heat treatment conducted in a reducing gas atmosphere; and cooling the heat-treated steel sheet at a temperature not lower than 380.degree. C. but not higher than the hot-dip galvanizing bath temperature, before the steel sheet is subjected to the hot-dip galvanizing. The very-low-carbon cold- rolled steel sheet contains, besides not less than 0.01 wt % but not more than 0.1 wt % of Ti, not more than 0.005 wt % of C, not less than 0.01 wt % but not more than 0.

Abstract: A steel suitable for a hot working press tool used for a slab width sizing press comprises particular amounts of C, Si, Cr, Mn, Mo, V and N having a specific Cr equivalent, or particular amounts of C, Si, Mn, Mo, V, Cr and Ni having a specified Cr/Ni ratio.