To manufacture a high-quality welded pipe, there is provided a welded pipe manufacturing apparatus for manufacturing a welded pipe by bending a metal plate and welding butting end portions of the metal plate. The welded pipe manufacturing apparatus includes a bending unit that bends the metal plate, a light emitter that emits directional light to an inner surface of the metal plate bent by the bending unit, an image capturing unit that captures light emitted by the light emitter and reflected by a surface of the metal plate, and an adjustment assistance unit that assists adjustment of the bending unit in accordance with a shape of the reflected light.

Provided is a welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured. This welding monitoring apparatus includes an image capturing unit that captures images of a region including the V-convergence region in time series; and an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.

A method of forming a tubular structure includes mechanically pickling a metal strip. The metal strip includes opposing first and second surfaces. The method also includes stippling indicia onto the first surface of the metal strip. The indicia includes an informational pattern. The method further includes forming the metal strip into a tubular structure such that the first surface forms an interior surface of the tubular structure.

This disclosure relates to a method for manufacturing a double pipe, including: a primary roll forming step of forming bending portions on both sides of a strip for an external pipe in a longitudinal direction; a stacking step of stacking a strip for an internal pipe on the strip for the external pipe; a secondary roll forming step of mechanically coupling the strip for the external pipe and the strip for the internal pipe; a forming step of forming the strip for the external pipe and the strip for the internal pipe, mechanically coupled to each other, into a pipe shape; a welding step of bonding the bending portions on both sides of the strip for the external pipe, and the strip for the internal pipe, which are formed into the pipe shape; and a heat treatment step of heat-treating bonded portions of the strip.

An apparatus and a process is disclosed for applying a boron coating to a thin foil. Preferably, the process is a continuous, in-line process for applying a coating to a thin foil comprising wrapping the foil around a rotating and translating mandrel, cleaning the foil with glow discharge in an etching chamber as the mandrel with the foil moves through the chamber, sputtering the foil with boron carbide in a sputtering chamber as the mandrel moves through the sputtering chamber, and unwinding the foil off the mandrel after it has been coated. The apparatus for applying a coating to a thin foil comprises an elongated mandrel. Foil preferably passes from a reel to the mandrel by passing through a seal near the initial portion of an etching chamber. The mandrel has a translation drive system for moving the mandrel forward and a rotational drive system for rotating mandrel as it moves forward. The etching chamber utilizes glow discharge on a surface of the foil as the mandrel moves through said etching chamber. A sputtering chamber, downstream of the etching chamber, applies a thin layer comprising boron onto the surface of the foil as said mandrel moves through said sputtering chamber. Preferably, the coated foil passes from the mandrel to a second reel by passing through a seal near the terminal portion of the sputtering chamber.

An electric resistance welded steel pipe for manufacturing a hollow stabilizer has a Lankford value in a pipe longitudinal direction of from 0.7 to less than 1.0. The electric resistance welded steel pipe is subjected to cold bending and then to a heat treatment including quenching and tempering to manufacture a stabilizer. The cold bending is cold rotary draw bending. When bent with a bend radius of from 1.0 times to 3.0 times an outer diameter of the pipe before cold bending, a flattening ratio is from 0% to 10%, a thickness reduction rate on a bending outside and a thickness increase rate on a bending inside are from 0% to 10%, and additionally, a circumferential length change of a bending center portion is from 0% to 10%. A Vickers hardness of the stabilizer after the heat treatment is adjusted to from 400 HV to less than 580 HV.

Provided is a welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured. This welding monitoring apparatus includes an image capturing unit that captures images of a region including the V-convergence region in time series; and an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.