A hot-rolled steel sheet includes a specific chemical composition, and includes a microstructure represented by, in vol %: retained austenite: 2% to 30%; ferrite: 20% to 85%; bainite: 10% to 60%; pearlite: 5% or less; and martensite: 10% or less. A proportion of grains having an intragranular misorientation of 5° to 14° in all grains is 5% to 50% by area ratio, the grain being defined as an area which is surrounded by a boundary having a misorientation of 15° or more and has a circle-equivalent diameter of 0.3 μm or more.

A hot-stamping formed body has a predetermined chemical composition and a microstructure including, by area ratio, 90% to 100% of martensite and 0% to 10% of a remainder in the microstructure. In the microstructure, a region in which an average GAIQ value in a unit grain is 60,000 or more is 30 area % or more, and a number density of carbides having a circle equivalent diameter of 0.20 μm or more is 50/mm.sup.2 or less.

Provided is an abrasion-resistant steel plate excellent in both abrasion resistance and wide bending workability. An abrasion-resistant steel plate comprises a specific chemical composition, wherein a volume fraction of martensite at a depth of 1 mm from a surface of the abrasion-resistant steel plate is 90% or more, a number density of TiC precipitates of 0.5 μm or more in equivalent circular diameter at a depth of 1 mm from the surface is 400/mm.sup.2 or more, hardness at a depth of 1 mm from the surface is 360 HBW 10/3000 or more in Brinell hardness, and a transverse direction hardness difference is 30Hv10 or less in Vickers hardness, the transverse direction hardness difference being defined as a difference in the hardness at a depth of 1 mm from the surface between two points adjacent at intervals of 10 mm in a transverse direction of the abrasion-resistant steel plate.

A method for producing a case-hardened martensitic stainless steel article includes: providing an article comprised, at least in part, of a martensitic stainless steel, carburizing the article within a temperature range of 1625° F.-1680° F. (885° C.-916° C.), and then carbo-nitriding the article within a temperature range of 1575° F.-1625° F. (857° C.-885° C.). An article, such as a bearing ring, comprising such a case-hardened martensitic stainless steel is also disclosed.

Ferritic stainless steel that has excellent formability and ridging resistance and can be produced with high productivity is provided. The ferritic stainless steel has: a predetermined chemical composition; a microstructure containing ferrite crystal grains which satisfy at least one of a C concentration of 2C.sub.C or more and an N concentration of 2C.sub.N or more, the ferrite crystal grains having a volume fraction with respect to a whole volume of the microstructure of 5% or more and 50% or less, where C.sub.C and C.sub.N are respectively C content and N content in the steel in mass %; and a Vickers hardness of 180 or less.

A material and method are disclosed such that the material can be used to form functional metal pieces by producing an easily sintered layered body of dried metal paste. On a microstructural level, when dried, the metal paste creates a matrix of porous metal scaffold particles with infiltrant metal particles, which are positioned interstitially in the porous scaffold's interstitial voids. For this material to realize mechanical and processing benefits, the infiltrant particles are chosen such that they pack in the porous scaffold piece in a manner which does not significantly degrade the packing of the scaffold particles and so that they can also infiltrate the porous scaffold on heating. The method of using this paste provides a technique deposition/removal process.

The invention relates to a method for producing a flat steel product made of a medium manganese steel having a TRIP/TWIP effect. The aim of the invention is to achieve an improvement in the yield strength when a sufficient residual deformability of the produced flat steel product is obtained. This aim is achieved by the following steps: cold rolling a hot or cold strip, annealing the cold-rolled hot or cold strip at 500 to 840° C. for 1 minute to 24 hours, temper rolling or finishing the annealed hot or cold strip to form a flat steel product having a degree of deformability between 0.3% and 60%. The invention further relates to a flat steel product produced according to said method and to a use thereof.

Disclosed is a steel composition including specified ranges of Ni; Mo; Co; Mo+Co+Si+Mn+Cu+W+V+Nb+Zr+Ta+Cr+C; Co+Mo; Ni+Co+Mo; and traces of Al; Ti; N; Si; Mn; C; S; P; B; H; O; Cr; Cu; W; Zr; Ca; Mg; Nb; V; and Ta in specified ranges; the remainder being iron and impurities. The inclusion population, as observed by image analysis over a polished surface measuring 650 mm.sup.2 if hot-formed or hot-rolled; and measuring 800 mm.sup.2 if cold-rolled, does not contain non-metallic inclusions of diameter >10 μm, and, in the case of a hot-rolled sheet, does not contain more than four non-metallic inclusions of diameter 5-10 μm over 100 mm.sup.2, the observation being performed by image analysis over a polished surface measuring 650 mm.sup.2.

A method of producing a CoFe alloy strip is provided. The method comprises hot rolling a CoFe alloy to form a hot rolled strip, followed by quenching the strip from a temperature above 700° C. to a temperature of 200° C. The CoFe alloy comprises an order/disorder temperature T.sub.o/d and a ferritic/austenitic transformation temperature T.sub.α/γ, wherein T.sub.α/γ>T.sub.o/d. The method further comprises cold rolling the hot rolled strip, after cold rolling, continuous annealing the strip at a maximum temperature T.sub.1, wherein 500° C.<T.sub.1<T.sub.o/d, followed by cooling at a cooling rate R.sub.1 of at least 1 K/s in the temperature range of T.sub.1 to 500° C., and after continuous annealing, magnetic annealing the strip, or parts manufactured from the strip, at a temperature between 730° C. and T.sub.α/γ.

Provided is a material for a cold-rolled stainless steel sheet having a chemical composition containing, by mass %, C: 0.01% to 0.05%, Si: 0.02% to 0.75%, Mn: 0.1% to 1.0%, P: 0.04% or less, S: 0.01% or less, Cr: 16.0% to 18.0%, Al: 0.001% to 0.10%, N: 0.01% to 0.06% and the balance being Fe and inevitable impurities. The material has a metallographic structure including a martensite phase having an area ratio of 5% to 50% and the balance being a ferrite phase. A ferrite phase in portions extending from surface layers of front and back surfaces of a steel sheet has an average grain diameter of 20 μm or more and 50 μm or less, and a ferrite phase in a central portion of the sheet includes an unrecrystallized ferrite phase.