When a rod-shaped workpiece (W) having an outer peripheral surface with a circular cross section is inductively heated to a quenching temperature while being conveyed at a predetermined velocity along an axial direction of the rod-shaped workpiece (W), the rod-shaped workpiece (W) being currently conveyed is heated to a predetermined temperature equal to or lower than the quenching temperature by a first heating coil (2A), which is electrically connected to a first high-frequency power supply (3) and has a constant output. Then, the rod-shaped workpiece (W) being currently conveyed is heated so as to be maintained at the quenching temperature by a second heating coil (2B), which is electrically connected to a second high-frequency power supply (4) and has a constant output.

When a rod-shaped workpiece (W) having an outer peripheral surface with a circular cross section is inductively heated to a quenching temperature while being conveyed at a predetermined velocity along an axial direction of the rod-shaped workpiece (W), the rod-shaped workpiece (W) being currently conveyed is heated to a predetermined temperature equal to or lower than the quenching temperature by a first heating coil (2A), which is electrically connected to a first high-frequency power supply (3) and has a constant output. Then, the rod-shaped workpiece (W) being currently conveyed is heated so as to be maintained at the quenching temperature by a second heating coil (2B), which is electrically connected to a second high-frequency power supply (4) and has a constant output.

A steel alloy is disclosed that provides a unique combination of strength, toughness, and fatigue life. The steel alloy has the following composition in weight percent:

TABLE-US-00001 C about 0.15 to about 0.30 Mn about 1.7 to about 2.3 Si about 0.7 to about 1.1 Cr about 1.85 to about 2.35 Ni about 0.5 to about 0.9 Mo + W about 0.1 to about 0.3 Cu about 0.3 to about 0.7 V + 5/9 Nb about 0.2 to about 0.5
The balance of the alloy is iron, usual impurities, and residual amounts of other elements added during melting for deoxidizing and/or desulfurizing the alloy. A hardened and tempered steel article made from the alloy is also disclosed.

A steel alloy is disclosed that provides a unique combination of strength, toughness, and fatigue life. The steel alloy has the following composition in weight percent:

TABLE-US-00001 C about 0.15 to about 0.30 Mn about 1.7 to about 2.3 Si about 0.7 to about 1.1 Cr about 1.85 to about 2.35 Ni about 0.5 to about 0.9 Mo + W about 0.1 to about 0.3 Cu about 0.3 to about 0.7 V + 5/9 Nb about 0.2 to about 0.5
The balance of the alloy is iron, usual impurities, and residual amounts of other elements added during melting for deoxidizing and/or desulfurizing the alloy. A hardened and tempered steel article made from the alloy is also disclosed.

The present disclosure relates to a steel, a steel structural part, an electronic device, and a steel structural part preparation method. An example steel includes Fe with a weight percentage of ?60.67 wt %, Cr with a weight percentage of 8.01 wt % to 8.99 wt %, Ni with a weight percentage of 6 wt % to 7 wt %, Co with a weight percentage of 15.01 wt % to 15.99 wt %, Mo with a weight percentage of 5.5 wt % to 6.5 wt %, Nb with a weight percentage of ?0.5 wt %, O with a weight percentage of ?0.3 wt %, and C with a weight percentage of ?0.05 wt %.

This application relates to lightweight steels, preparation methods thereof, and steel structural parts and electronic devices that use the lightweight steel. An example light weight steal includes: Fe, in a percentage by weight greater than or equal to 48.18 wt %; Mn, in a percentage by weight of 30.01 wt % to 35.01 wt %; Al, in a percentage by weight of 12.01 wt % to 15.01 wt %; C, in a percentage by weight of 1.0 wt % to 1.5 wt %; and O, in a percentage by weight of 0.03 wt % to 0.3 wt %. This application further provides a steel structural part, an electronic device that use the lightweight steel, and a preparation method of the lightweight steel.

Provided is a rail vehicle axle having an excellent fatigue limit and notch factor. A rail vehicle axle according to the present embodiment has a chemical composition consisting of, in mass %, C: 0.20 to 0.35%, Si: 0.20 to 0.65%, Mn: 0.40 to 1.20%, P: 0.020% or less, S: 0.020% or less, Sn: 0.07 to 0.40%, N: 0.0200% or less, Cu: 0 to 0.30%, Ni: 0 to 0.30%, Cr: 0 to 0.30%, Mo: 0 to 0.08%, Al: 0 to 0.100%, V: 0 to 0.060%, and Ti: 0 to 0.020%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2):
0.58?C+Si/8+Mn/5+Cu/10+Cr/4+V?0.67(1)
Si+0.9Cr?0.50(2) where, each element symbol in Formulae (1) and (2) is substituted by the content (mass %) of a corresponding element.

Provided is a rail vehicle axle having an excellent fatigue limit and notch factor. A rail vehicle axle according to the present embodiment has a chemical composition consisting of, in mass %, C: 0.20 to 0.35%, Si: 0.20 to 0.65%, Mn: 0.40 to 1.20%, P: 0.020% or less, S: 0.020% or less, Sn: 0.07 to 0.40%, N: 0.0200% or less, Cu: 0 to 0.30%, Ni: 0 to 0.30%, Cr: 0 to 0.30%, Mo: 0 to 0.08%, Al: 0 to 0.100%, V: 0 to 0.060%, and Ti: 0 to 0.020%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2):
0.58?C+Si/8+Mn/5+Cu/10+Cr/4+V?0.67(1)
Si+0.9Cr?0.50(2) where, each element symbol in Formulae (1) and (2) is substituted by the content (mass %) of a corresponding element.

A process for reducing film boiling by keeping the quenchant pressure above the vapor pressure of the liquid quenchant, and/or using a controlled quenchant renewal to more uniformly cool the surface of part at the initial moment of contact and apparatuses to conduct the pressure and controlled quenchant renewal are disclosed. It is believed that these processes will improve the heat treating of parts with intricate geometries to provide predictable part distortion. The applicability of the method to gun barrels, tubes, round rings, and hollow axles is explained.

A method for manufacturing an at least sectionally spherical-cap-shaped recess on a drive shaft for a hydrostatic axial piston machine includes whirling of the recess and heat treatment of the recess to form a wear layer. A drive shaft for a hydrostatic axial piston machine includes at least one recess manufactured according to the method. A hydrostatic axial piston machine includes a drive shaft with at least one recess manufactured according to the method.