A heating step, in which a stainless member is heated to a temperature within or above a heating phase-transformation temperature range (Ar) in which the stainless member is phase-transformed, is executed. A cooling step in which the stainless member heated in the heating step is cooled to a temperature below a cooling phase-transformation temperature range (Mr) in which the stainless member is phase-transformed, is executed. In the cooling step, cooling of the stainless member is suppressed in a control temperature range including the cooling phase-transformation temperature range (Mr).

A heating step, in which a stainless member is heated to a temperature within or above a heating phase-transformation temperature range (Ar) in which the stainless member is phase-transformed, is executed. A cooling step in which the stainless member heated in the heating step is cooled to a temperature below a cooling phase-transformation temperature range (Mr) in which the stainless member is phase-transformed, is executed. In the cooling step, cooling of the stainless member is suppressed in a control temperature range including the cooling phase-transformation temperature range (Mr).

The invention relates to a steel for a tool holder. The steel comprises the following main components (in wt. %): C 0.07-0.13 Si 0.10-0.45 Mn 1.5-3.1 Cr 2.4-3.6 Ni 0.5-2.0 Mo 0.1-0.7 Al 0.001-0.06 S0.003

The steel has a bainitic microstructure comprising up to 20 volume % retained austenite and up to 20 volume % martensite.

Provided is a carbonitrided bearing part which has high hardenability and toughness, and is excellent in wear resistance and surface-originated flaking life. A carbonitrided bearing part of the present embodiment has a chemical composition containing, in mass %, C: 0.15 to 0.45%, Si: not more than 0.50%, Mn: 0.40 to 1.50%, P: not more than 0.015%, S: not more than 0.005%, Cr: 0.30 to 2.0%, Mo: 0.10 to 0.35%, V: 0.20 to 0.40%, Al: 0.005 to 0.10%, N: not more than 0.030%, and O: not more than 0.0015%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2). At surface, C concentration is 0.7 to 1.2%, N concentration is 0.15 to 0.6%, and Rockwell hardness HRC is 58 to 65.
1.20<0.4Cr+0.4Mo+4.5V<2.60(1)
2.7C+0.4Si+Mn+0.8Cr+Mo+V>2.20(2)

A martensitic stainless steel alloy is strengthened by copper-nucleated nitride precipitates. The alloy includes, in combination by weight percent, about 10.0 to about 12.5 Cr, about 2.0 to about 7.5 Ni, up to about 17.0 Co, about 0.6 to about 1.5 Mo, about 0.5 to about 2.3 Cu, up to about 0.6 Mn, up to about 0.4 Si, about 0.05 to about 0.15 V, up to about 0.10 N, up to about 0.035 C, up to about 0.01 W, and the balance Fe and incidental elements and impurities. The nitride precipitates may be enriched by one or more transition metals. A case hardened, corrosion resistant variant has a reduced weight percent of Ni, enabling increased use of Cr, and decreased Co.

A martensitic stainless steel alloy is strengthened by copper-nucleated nitride precipitates. The alloy includes, in combination by weight percent, about 10.0 to about 12.5 Cr, about 2.0 to about 7.5 Ni, up to about 17.0 Co, about 0.6 to about 1.5 Mo, about 0.5 to about 2.3 Cu, up to about 0.6 Mn, up to about 0.4 Si, about 0.05 to about 0.15 V, up to about 0.10 N, up to about 0.035 C, up to about 0.01 W, and the balance Fe and incidental elements and impurities. The nitride precipitates may be enriched by one or more transition metals. A case hardened, corrosion resistant variant has a reduced weight percent of Ni, enabling increased use of Cr, and decreased Co.

Alloys, a process for preparing the alloys, and manufactured articles including the alloys are described herein. The alloys include, by weight, about 11.5% to about 14.5% chromium, about 0.01% to about 3.0% nickel, about 0.1% to about 1.0% copper, about 0.1% to about 0.2% carbon, about 0.01% to about 0.1% niobium, 0% to about 5% cobalt, 0% to about 3.0% molybdenum, and 0% to about 0.5% titanium, the balance essentially iron and incidental elements and impurities.

Alloys, a process for preparing the alloys, and manufactured articles including the alloys are described herein. The alloys include, by weight, about 11.5% to about 14.5% chromium, about 0.01% to about 3.0% nickel, about 0.1% to about 1.0% copper, about 0.1% to about 0.2% carbon, about 0.01% to about 0.1% niobium, 0% to about 5% cobalt, 0% to about 3.0% molybdenum, and 0% to about 0.5% titanium, the balance essentially iron and incidental elements and impurities.

Provided is a blade material having high strength. The blade material contains, in % by mass, 0.5 to 0.8% of C, 1.0% or less of Si, 1.0% or less of Mn, 11 to 15% of Cr, and 0.1 to 0.8% of V, the remainder includes Fe and inevitable impurities, and has a thickness of 0.5 mm or less, wherein the structure of the blade material as observed after polishing the surface thereof has ferrites and carbides, the carbides have an average particle diameter of 0.5 m or less, and a proportion of carbides containing V in the carbides is 50% or less in terms of a proportion in an area of a field of view.

A hot-pressed steel sheet member includes: a specific chemical composition; and a steel microstructure represented by, in area %, ferrite: 10% to 70%, martensite: 30% to 90%, and a total area ratio of ferrite and martensite: 90% to 100%. 90% or more of all Ti in steel precipitates, and a tensile strength of the hot-pressed steel sheet member is 980 MPa or more.