A stabilizer formed by using a metal bar having a solid structure and configured to reduce a displacement between right and left wheels, including a torsion part extending in a vehicle width direction, being capable of a torsional deformation, and having a diameter of 10 to 32 mm, is provided. The stabilizer has a chemical composition containing at least C: 0.15% by mass or more to 0.39% by mass or less, Mn, B, and Fe, and also has a metal structure 90% or more of which is a martensite structure.

The invention provides a production method for stabilizers which produces with high productivity in a compact production line, without tempering. The production method for stabilizers of the invention includes: forming a steel bar material containing at least C: 0.15 wt % to 0.39 wt %, Mn, B and Fe into a product shape by bending; and quenching the bent steel bar material in a medium having a heat transfer coefficient higher than or close to that of water.

The invention provides a production method for stabilizers which produces with high productivity in a compact production line, without tempering. The production method for stabilizers of the invention includes: forming a steel bar material containing at least C: 0.15 wt % to 0.39 wt %, Mn, B and Fe into a product shape by bending; and quenching the bent steel bar material in a medium having a heat transfer coefficient higher than or close to that of water.

A vibropeening apparatus comprises a main frame, an enclosure receivable within the main frame, a rotary drive mechanism, and an article to be vibropeened. The enclosure defines an internal volume, the internal volume accommodating a vibropeening bed. The article is positioned within the internal volume, and the rotary drive mechanism is to configured to impart a rotary motion to the enclosure within the main frame.

A vibropeening apparatus comprises a main frame, an enclosure receivable within the main frame, a rotary drive mechanism, and an article to be vibropeened. The enclosure defines an internal volume, the internal volume accommodating a vibropeening bed. The article is positioned within the internal volume, and the rotary drive mechanism is to configured to impart a rotary motion to the enclosure within the main frame.

Improved steel compositions and methods of making the same are provided. More particularly, the present disclosure provides high manganese (Mn) steel having enhanced strength and/or performance at cryogenic temperatures, and methods for fabricating high manganese steel compositions having enhanced strength and/or performance at cryogenic temperatures. The advantageous steel compositions/components of the present disclosure improve one or more of the following properties: strength, toughness, elastic modulus, thermal expansion coefficient and/or thermal conductivity. In general, the present disclosure provides high manganese steels tailored to resist wear and/or deformation at cryogenic temperatures.

A fluid end having a longitudinal bore less than about 36 inches in diameter has an internal surface that is cold-worked to have compressive stresses of at least 15 ksi (103.42 MPa) beneath the metal surface up to about 40 mils (1.016 mm).

A tool for cold-working a metal substrate of a longitudinal bore having a diameter less than about eight inches includes a deflector tip configured to direct accelerated shot having diameters on average not larger than 100 mils (2.54 mm) toward a surface of the metal substrate at an angle between about 70 degrees and about 85 degrees relative to the surface, thereby providing increased compressive stresses in the metal substrate.

A tool for cold-working a metal substrate of a longitudinal bore having a diameter less than about eight inches includes a deflector tip configured to direct accelerated shot having diameters on average not larger than 100 mils (2.54 mm) toward a surface of the metal substrate at an angle between about 70 degrees and about 85 degrees relative to the surface, thereby providing increased compressive stresses in the metal substrate.

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.