A paramagnetic stainless steel with a chemical composition may include iron and, by weight: 20≤Cr≤40%; 3≤Ni≤20%; 0≤Mn≤15%; 0≤Al≤5%; 3≤Mo≤15%; 0≤W≤5%; 0≤Cu≤2%; 0≤Si≤5%; 0≤Ti≤1%; 0≤Nb≤1%; 0≤C≤0.1%; 0≤N≤0.5%; 0≤S≤0.5%; 0≤P≤0.1%, and optionally impurities, each at a concentration of less than or equal to 0.5%. The steel may have a hardness in a range of from 575 to 900 HV10. A part, in particular a timepiece component, may be made from or include this steel.

A secondary cooling control method for reinforcing surface solidification structure of microalloyed steel continuous casting bloom includes: in situ observing precipitation behavior of secondary phase particles of the microalloyed steel, and determining a concentrated precipitation temperature range; cooling the microalloyed steel at different cooling rates, obtaining a particle size and a volume fraction of the secondary phase particles of the microalloyed steel at different cooling rates; determining an optimal average cooling rate; determining an optimal average cooling rate r; determining an optimal average cooling rate; and determining an optimal average cooling rate range through intersection of the three optimal average cooling rates whereby the continuous casting secondary cooling is optimized. The present invention can enhance the surface solidification structure of continuous casting bloom and reduce surface and subsurface cracks of the microalloyed steel continuous casting bloom.

A secondary cooling control method for reinforcing surface solidification structure of microalloyed steel continuous casting bloom includes: in situ observing precipitation behavior of secondary phase particles of the microalloyed steel, and determining a concentrated precipitation temperature range; cooling the microalloyed steel at different cooling rates, obtaining a particle size and a volume fraction of the secondary phase particles of the microalloyed steel at different cooling rates; determining an optimal average cooling rate; determining an optimal average cooling rate r; determining an optimal average cooling rate; and determining an optimal average cooling rate range through intersection of the three optimal average cooling rates whereby the continuous casting secondary cooling is optimized. The present invention can enhance the surface solidification structure of continuous casting bloom and reduce surface and subsurface cracks of the microalloyed steel continuous casting bloom.

A rolled steel sheet, for press hardening is provided, having a chemical composition where Ti/N>3.42, and the carbon, manganese, chromium and silicon contents satisfy:

[00001]$2.6C+\frac{\mathrm{Mn}}{5.3}+\frac{\mathrm{Cr}}{13}+\frac{\mathrm{Si}}{15}\ge 1.1\%.$

The sheet has a nickel content Ni.sub.surf at any point of the steel in the vicinity of the surface over a depth Δ, such that: Ni.sub.surf>Ni.sub.nom, Ni.sub.nom denoting the nominal nickel content of the steel, and such that, Ni.sub.max denoting the maximum nickel content within Δ:

[00002]$\frac{\left({\mathrm{Ni}}_{\max }+{\mathrm{Ni}}_{\mathrm{nom}}\right)}{2}\times \left(\Delta \right)\ge 0.6,$

and such that:

[00003]$\frac{\left({\mathrm{Ni}}_{\max }-{\mathrm{Ni}}_{\mathrm{nom}}\right)}{\Delta }\ge 0.01$

and the surface density of all of the particles D.sub.i , and the surface density of the particles D.sub.(>2 μm) larger than 2 micrometers satisfy, at least to a depth of 100 micrometers in the vicinity of the surface of said sheet:

D.sub.i+6.75 D.sub.(>2 μm)<270

D.sub.i and D.sub.(>2 μm) being expressed as number of particles per square millimeter, and said particles denoting all the oxides, sulfides, and nitrides, either pure or combined such as oxysulfides and carbonitrides, present in the steel matrix.

The present invention relates to steel sheet realizing both formability and weldability. The steel sheet of the present invention is characterized in that at a surface layer part of a region down to 30 μm from the surface of the steel sheet in the sheet thickness direction, Si oxide grains are present in 3000 to 6000/mm.sup.2 in number density, an average of natural logarithms of the particle sizes of the Si oxide grains measured in μm units is −2.0 to −1.2, the standard error of the natural logarithms of the particle sizes is 0.6 or less, and the number of Si oxide grains with deviations of the natural logarithms of the particle sizes from the average larger than 2 times the standard error is 5% or less of the total number of Si oxide grains and at a position of ½ of the thickness of the steel sheet, the number density of the Si oxide grains is 1000/mm.sup.2 or less.

A highly corrosion-resistant austenite stainless steel that, even when exposed to temperatures in a range in which a σ phase is precipitated and corrosion resistance varies greatly, the stainless steel remains corrosion resistant, the steel consisting of, in mass %: C: 0.005 to 0.030%, Si: 0.05 to 0.30%, Mn: 0.05 to 0.40%, P: 0.005 to 0.050%, S: 0.0001 to 0.0010%, Ni: 22.0 to 32.0%, Cr: 19.0 to 28.0%, Mo: 5.0 to 7.0%, N: 0.18 to 0.25%, Al: 0.005 to 0.100%, Cu: 0.05 to 0.50%, W: not more than 0.05%, Sn: 0.0005 to 0.0150%, Co: 0.030 to 0.300%, B: 0.0005 to 0.0050%, Fe as a remainder and inevitable impurities, in which the stainless steel satisfies the following formula (1), an area ratio of σ phase is not more than 1%, and CPT based on ASTM G48 Method C as corrosion resistance property is not less than 60° C.

0.05≤10[% B]+2[% P]+6[% Sn]+0.03[% Si]≤0.20  (1)

A waste gate component for a turbo charger made of a ferritic steel including C, Cr, Ni, Nb, V, Mn, and optionally Si, and Ti as main alloying elements.

A waste gate component for a turbo charger made of a ferritic steel including C, Cr, Ni, Nb, V, Mn, and optionally Si, and Ti as main alloying elements.

A spring wire which can be cold formed well at diameters of at least 9 mm, but has improved mechanical properties. The spring wire is manufactured from a steel including, in % by weight, C: 0.35-0.42%, Si: 1.5-1.8%, Mn: 0.5-0.8%, Cr: 0.05-0.25%, Nb: 0.020-0.10%, V: 0.020-0.10%, N: 0.0040-0.0120%, Al: ≤0.03% and as the remainder iron and unavoidable impurities, wherein the total content of impurities is limited to at most 0.2% and the impurities include up to 0.025% P and up to 0.025% S. The spring wire is in particular suitable for the manufacture of a tension clamp with optimized usage properties. Also, a method which enables the practice-oriented production of the spring wire.

The present invention relates to a metal alloy, characterized in that it comprises, in percent by weight on the total weight of the alloy, 1-4% of niobium (Nb), 0-0.5% of hafnium (Hf), 27-29% of chromium, 1-5% of nickel (Ni), 0.3-0.45% of carbon (C), 0-2% of tantalum (Ta), 0-2% of titanium, 1-3% of iron, less than 0.5% of manganese (Mn), less than 0.3% of silicon (Si), less than 0.2% of zirconium (Zr), the remainder being cobalt (Co) and unavoidable impurities. This metal alloy has superior mechanical strength characteristics at high temperature which make it suitable for the manufacture of a manufactured article, in particular a spinner, for the production of mineral fibers, such as glass fiber, rock fiber and the like.