A process for the industrial production of wear-resistant steel pipes having an optimized life. The process includes providing a wear-resistant, hardenable steel sheet in an unhardened or tempered state, shaping the steel sheet into a tubular preform in which two longitudinal edges of the steel sheet are positioned opposite one another with a welding gap extending between the two edges, welding the longitudinal edges by forming a welded seam which closes the welding gap, thereby forming a steel pipe, and heat treating the steel pipe. The heat treatment of the steel pipe includes heating the steel pipe at an average heating rate of 5-400 K/s to a hold temperature which is the Ac3 temperature of the steel and 1100 C., holding the steel pipe at the hold temperature for 1-120 s, and cooling the steel pipe at an average cooling rate of 10-600 K/s to room temperature.

Induction welding process for welding two parts using at least one susceptor including discontinuous conductive elements, and assembly of at least two parts obtained using the induction welding process. An induction welding process can join at least first and second parts, and the process can include a step of positioning at least one susceptor, including discontinuous conductive elements, between the first and second contact faces of the first and second parts, and steps of holding the first and second parts pressed against each other and of producing an electromagnetic field to generate an induced current that engenders heating of the susceptor. An assembly of two parts can be obtained using the process.

Induction welding process for welding two parts using at least one susceptor including discontinuous conductive elements, and assembly of at least two parts obtained using the induction welding process. An induction welding process can join at least first and second parts, and the process can include a step of positioning at least one susceptor, including discontinuous conductive elements, between the first and second contact faces of the first and second parts, and steps of holding the first and second parts pressed against each other and of producing an electromagnetic field to generate an induced current that engenders heating of the susceptor. An assembly of two parts can be obtained using the process.

An electric resistance welded pipe welding device for manufacturing an electric resistance welded pipe that melts both end face portions, of an open pipe having an opening portion extending in a running direction, both the end face portions that face the opening portion each other from both sides and are made of a pipe material, by induced currents generated by an induction heating means and brings the end face portions into contact with each other at a squeeze roll unit while gradually narrowing a gap of the opening portion and welds the end face portions together, the electric resistance welded pipe welding device includes: as the induction heating means, an induction coil composed of a pair of opening-vicinity conductor parts that are extended in the running direction along the end face portions at both sides of the opening portion and are arranged apart from an outer peripheral surface of the open pipe at positions not overlapping the opening portion in a plan view; and a first-portion circulating conductor part that is integrally provided at at least end portions, of the opening-vicinity conductor parts, on the side close to the squeeze roll unit in a longitudinal direction and is arranged apart from the outer peripheral surface of the open pipe so as to circulate around a portion, of the outer peripheral surface of the open pipe, excluding the opening portion.

An apparatus (10) for joining a predetermined geometrical profile shape from a sheet material (SM) includes a positioning assembly (12) including a base member (14) and a frame (16) that is operable to receive the sheet material (SM), to configure the sheet material in a predetermined orientation and to linearly translate the sheet material along a process direction (20). A Z-bar (22) is configured to guide a first longitudinal edge (FE) and second longitudinal edge (SE) of the sheet material (SM) into adjacent alignment along the process direction (20). A welding and forging assembly (60) welds and then forges a seam between the first longitudinal edge (FE) and the second longitudinal edge (SE) of the associated sheet material (SM).

The objective of the present invention is to enable accurate detection of a mismatch during electric resistance welding. This operation monitoring device for high-frequency resistance welding and induction heated welding of an electric resistance welded steel pipe, in which a strip-shaped metal sheet is continuously formed into a cylindrical shape by means of a group of rollers while being conveyed from an upstream side to a downstream side, and in which the two edge portions, in the circumferential direction, of the metal sheet, which are caused to converge into a V-shape, are caused to melt by the application of heat and are caused to abut one another, is characterized by being provided with a means for detecting a mismatch by recognizing a non-uniformity between light-emitting regions of a metal part, on both sides, in the circumferential direction, of the abutting position on an outer surface or an inner surface of the metal plate, on the basis of an image of a region including a V-convergence location, which is a location at which the two edge portions in the circumferential direction converge into said V-shape, and said metal part which is caused to flow out onto the surface of the metal plate by means of an electromagnetic force downstream of the V-convergence location, wherein said image is captured by means of an image capturing device from an outer surface side or an inner surface side of the metal plate that has been formed into said cylindrical shape.

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.

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.

Provided is a rotating body, including: a shaft; and a compressor impeller including: a main body having an insertion hole, which extends from one end to another end side and is configured to receive the shaft inserted therethrough; a boss portion formed at one end side of the main body; and a joint portion, which is formed on an inner peripheral surface of the insertion hole at the boss portion and is welded to the shaft.

Provided is a rotating body, including: a shaft; and a compressor impeller including: a main body having an insertion hole, which extends from one end to another end side and is configured to receive the shaft inserted therethrough; a boss portion formed at one end side of the main body; and a joint portion, which is formed on an inner peripheral surface of the insertion hole at the boss portion and is welded to the shaft.