A nanocrystalline bainitic steel consisting of, by weight percentage: 0.3% to 0.6% carbon; 9.0% to 20.0% nickel; up to 10% cobalt; 1.0% to 4.5% aluminium; up to 0.5% molybdenum; up to 0.5% manganese; up to 0.5% tungsten; up to 3.0% chromium; and the balance being iron and impurities.

An R-T-B based permanent magnet includes main phase grains composed of R.sub.2T.sub.14B type compound. R is a rare earth element. T is iron group element(s) essentially including Fe or Fe and Co. B is boron. The magnet contains at least C, Ga, and M selected from Zr, Ti, and Nb in addition to R, T, and B. B is contained at 0.71 mass % to 0.88 mass %. C is contained at 0.15 mass % to 0.34 mass %. Ga is contained at 0.40 mass % to 1.40 mass %. M is contained at 0.25 mass % to 2.50 mass %. A formula (1) of 0.14≦[C]/([B]+[C])≦0.30 and a formula (2) of 5.0≦[B]+[C]−[M]≦5.6 are satisfied, where [B], [C], and [M] are respectively a content of B, C, and M by atom %.

This ferritic stainless steel sheet contains, by mass %: C: 0.001% to 0.020%; Si: 0.01% to 4.00%; Mn: 0.01% to 3.00%; P: 0.010% to 0.040%; S: 0.0001% to 0.0100%; Cr: 10.0% to 15.0%; N: 0.001% to 0.020%; Al: 0.50% to 10.0%; and either one or both of Ti: 0.05% to 0.40% and Nb: 0.05% to 0.40%, with the balance being Fe and unavoidable impurities, in which Cr/(Si+Al) is 10.0 or less, and a specific gravity is 7.6 g/cm.sup.3 or less.

The present invention discloses a rare earth permanent magnet and a method for preparing same. The material of the rare earth permanent magnet has a heavy rare earth element volume diffusion phenomenon at a depth of 5 μm to 100 μm from the surface of the magnet to the interior of the magnet along the magnetic field orientation direction, thereby forming a volume diffusion layer region; the volume diffusion layer region is divided into magnet units having a volume of 10*100*5 μm, and the concentration difference of the heavy rare earth elements of the magnet units at different positions in the volume diffusion layer is below 0.5 at %. The present invention provides a sintered NdFeB magnet of high intrinsic coercive force Hcj on the premise of not influencing the remanence Br and the maximum magnetic energy product (BH)max of products. In the method for preparing the rare earth permanent magnet, microwave heat treatment is performed on a blank magnet coated with heavy rare earth source slurry in a vacuum condition. This method can effectively improve the heating efficiency, reduce the heat treatment time, lower the energy consumption, and reduce the production cost of the magnet.

The present invention relates to a high entropy alloy having more improved mechanical properties by controlling contents of additive elements in a NiCoFeMnCr 5-element alloy to control stacking fault energy, thereby controlling stability of a γ austenite phase to control a transformation mechanism, wherein the stacking fault energy is controlled in a composition range of Ni.sub.aCo.sub.bFe.sub.cMn.sub.dCr.sub.e (a+b+c+d+e=100, 1≦a≦50, 1≦b≦50, 1≦c≦50, 1≦d≦50, 10≦e≦25, and 77a−42b−22c+73d−100e+2186≦1500), and thus, the γ austenite phase exhibits a twin-induced plasticity (TWIP) property or a transformation induced-plasticity (TRIP) property in which the γ austenite phase is subjected to phase transformation into an ε martensite phase or an α′ martensite phase, under stress, thereby having improved strength and elongation at the same time to have excellent mechanical properties.

A drill string component, in particular a drilling collar component, an MWD component, or an LWD component for use in oilfield technology and particularly in deep drilling, is provided. A method of making a drill string component, and a steel alloy useful in making a drill string component, are also provided.

The seamless steel pipe according to the present disclosure includes a chemical composition consisting of, in mass %, C: 0.030% or less, Si: 1.00% or less, Mn: 1.00% or less, P: 0.030% or less, S: 0.0050% or less, Al: 0.001 to 0.100%, N: 0.0500% or less, O: 0.050% or less, Ni: 3.00 to 6.50%, Cr: more than 10.00 to 13.40%, Mo: 0.50 to 4.00%, V: 0.01 to 1.00%, Ti: 0.010 to 0.300%, and Co: 0.010 to 0.300%, with the balance being Fe and impurities, and satisfying Formula (1), and a microstructure containing, in volume ratio, 80.0% or more of martensite, wherein a depassivation pH of an inner surface is 3.50 or less.

Cr+2.0Mo+0.5Ni+0.5Co≥16.0  (1)

A Cr-based stainless steel sheet includes: 0.020 mass % or less of C; 1.00 mass % or less of Si; 1.00 mass % or less of Mn; 0.040 mass % or less of P; 0.0030 mass % or less of S; 10.0 to 18.0 mass % of Cr; 0.020 mass % or less of N; 0.10 mass % or less of Al; and one or both of 0.5 mass % or less of Nb and 0.5 mass % or less of Ti; in which a texture in a sheet surface satisfies (i) and (ii) below. (i) In the sheet surface, an area ratio of crystal grains ({211}±10-degree-oriented grains) whose orientation difference between a normal direction of the surface and a {211}-plane orientation is 10 degrees or less is less than 30%. (ii) For the {211}±10-degree-oriented grains, a length in a rolling direction and a length in a sheet width direction are each less than 0.15 mm on average.

Elements formed from magnetic materials and their methods of manufacture are presented. Magnetic materials include a magnetic alloy material, such as, for example, an Fe-Co alloy material (e.g., the Fe-Co-V alloy Hiperco-50(R)). The magnetic alloy materials may comprise a powdered material suitable for use in additive manufacturing techniques, such as, for example direct energy deposition or laser powder bed fusion. Manufacturing techniques include the use of variable deposition time and energy to control the magnetic and structural properties of the materials by altering the microstructure and residual stresses within the material. Manufacturing techniques also include post deposition processing, such as, for example, machining and heat treating. Heat treating may include a multi-step process during which the material is heated, held and then cooled in a series of controlled steps such that a specific history of stored internal energy is created within the material. Magnetic elements may include, for example, motors, generators, solenoids and swtiches, sensors, transformers, and hall thrusters, among other elements.

Rare earth-containing alloy flakes and a sintered magnet made of the same are provided, which alloy flakes are useful in the production of sintered magnets of which Br and HcJ may be excellent and well-balanced according to the Dy and/or Tb content. The rare earth-containing alloy flakes are R-TM-A-M-type alloy flakes which have a particular composition, and a structure having a Nd.sub.2Fe.sub.14B main phase and a boundary phase, the Fe content in the boundary phase is not more than 10 mass %, and a ratio of the total content (b) of Dy and Tb in the boundary phase to the total content (a) of Dy and Tb in the main phase is higher than 1.0, and are useful as a sintered magnet material.