This cooling device includes a first cooling mechanism and a second cooling mechanism. The first cooling mechanism includes a first nozzle disposed to be aligned with a heating coil on a downstream side and whose injection direction of a refrigerant is a first injection direction, a second nozzle disposed to be aligned with the first nozzle on a downstream side and whose injection direction of the refrigerant is a second injection direction intersecting the first injection direction, a first valve selectively switching a supply destination of the refrigerant between one and the other of the first nozzle and the second nozzle, and a first control unit controlling the first valve. The second cooling mechanism includes a third nozzle disposed on a side opposite to the first nozzle and the second nozzle with the extension line sandwiched therebetween and whose injection direction of the refrigerant is a third injection direction forming an angle of 20 degrees or more and 70 degrees or less with respect to a bent inner circumferential surface of a bent portion.

According to the present invention, there is provided a cooling apparatus for a steel material in which one portion in a longitudinal direction of an elongated steel material (10) is heated while the steel material is fed in the longitudinal direction in a state where one end portion of the steel material is gripped, and the one end portion is moved in a two-dimensional or three-dimensional direction so as to form the steel material into a predetermined shape including a bent portion and thereafter to cool a heated portion including the bent portion. The cooling apparatus includes a first cooling apparatus (22) that ejects a first cooling medium to the heated portion, and a second cooling apparatus (23) that is disposed on a downstream side from the first cooling apparatus when viewed along a feeding direction of the steel material, and that ejects a second cooling medium to the heated portion. A plurality of the second cooling apparatuses are disposed along the feeding direction, and flow rates of the second cooling media can be controlled independently of each other. According to the configuration, it is possible to reduce the insufficient quenching of the steel material.

A method for manufacturing a bent member, the method includes feeding an elongated steel material in a longitudinal direction with one end portion of the steel material as a head, performing high-frequency induction heating to one portion of the steel material in the longitudinal direction by being supplied high-frequency power to form a high-temperature portion, bending the steel material by applying a bending moment in an arbitrary direction to the high-temperature portion to form a bent portion, and injecting a cooling medium to the bent portion to cool the bent portion. The bending includes forming the bent portion having a ratio R/W which is equal to or lower than a predetermined value, where the ratio R/W is a ratio obtained by dividing a bending radius R [mm] of the bent portion on a centroid line of the steel material by a dimension W [mm] in a bend direction in a cross-section of the steel material orthogonal to the centroid line, slowing down a feeding speed of the steel material less than V1, where the V1 is the feeding speed of the steel material while forming the bent portion having the ratio R/W which is more than the predetermined value, and reducing the high-frequency power supplied while forming the high-temperature portion less than Q1, where the Q1 is the high-frequency power supplied while forming the bent portion having the ratio R/W which is more than the predetermined value.

In one embodiment, a method for manufacturing a pipe bend is disclosed, comprising: heating, with an induction coil, a first annular band of a wall of a first end portion of a moving pipe; directing quenching fluid toward an outer and inner surface of the first annular band; heating a second annular band of a wall of a bend portion of the moving pipe; directing the quenching fluid toward an outer and inner surface of the second annular band; decreasing a speed of the pipe while moving the induction coil from stationary and maintaining a relative speed between the pipe and the induction coil substantially constant; heating a third annular band of a wall of a second end portion of the pipe while moving the induction coil; and directing the quenching fluid toward an outer surface and an inner surface of the third annular band while moving the induction coil.

According to the present invention, there is provided a cooling apparatus for a steel material in which one portion in a longitudinal direction of an elongated steel material (10) is heated while the steel material is fed in the longitudinal direction in a state where one end portion of the steel material is gripped, and the one end portion is moved in a two-dimensional or three-dimensional direction so as to form the steel material into a predetermined shape including a bent portion and thereafter to cool a heated portion including the bent portion. The cooling apparatus includes a first cooling apparatus (22) that ejects a first cooling medium to the heated portion, and a second cooling apparatus (23) that is disposed on a downstream side from the first cooling apparatus when viewed along a feeding direction of the steel material, and that ejects a second cooling medium to the heated portion. A plurality of the second cooling apparatuses are disposed along the feeding direction, and flow rates of the second cooling media can be controlled independently of each other. According to the configuration, it is possible to reduce the insufficient quenching of the steel material.

A heat treatment apparatus of one aspect of the present disclosure includes: a feed device that feeds a heat treatment workpiece downstream in a feed direction along a heat treatment workpiece pass-line; a heating device that includes a heating coil disposed downstream of the feed device in the feed direction and encircling the pass-line; a cooling device that is disposed adjacent to the heating coil, downstream of the heating coil in the feed direction, and encircling the pass-line; and a gas supply device that is disposed upstream of the heating coil in the feed direction, directly connected to the heating coil and encircling the pass-line, and that includes a plurality of gas compartments configured by internally partitioning the gas supply device in the feed direction.

To provide a technique capable of preventing or suppressing fatigue failure of a vehicle underbody part material by 3DQ. A vehicle underbody part material relating to this disclosure includes: a quenched and bent steel pipe; and a plating film layer provided on a surface of the steel pipe and containing 30 mass % or more of Al and having an AlFe alloy existing in a surface thereof.

The present invention includes: a conveying mechanism (110) that conveys a workpiece (200) in the longitudinal direction; a supporting mechanism (120) that is arranged on the downstream side in the conveyance direction of the workpiece (200) from the conveying mechanism (110); and a heating mechanism (130) that is arranged on the downstream side in the conveyance direction of the workpiece (200) from the supporting mechanism (120) and heats the workpiece (200), in which the supporting mechanism (120) is formed to include support rolls (121) that abut on an outer surface of the workpiece (200) and each include a hollow structure (122) allowing a cooling medium to pass therethrough therein.

A bending apparatus has (a) a first manipulator which feeds a hollow metal blank of closed cross section in its lengthwise direction, (b) a second manipulator which supports a first support means disposed at a first position and a metal blank while feeding it, a heating means disposed at a second position downstream of the first position in the blank feed direction for heating all or part of the circumference of the blank, and a cooling means disposed at a third position downstream of the second position for cooling a portion of the heated blank, and (c) a third manipulator which constitutes a second support means disposed at a fourth position downstream of the third position in the feed direction of the blank and which moves two-dimensionally or three-dimensionally while supporting at least one location of the metal blank to bend the metal blank into a desired shape.

A system is provided for manufacturing a pipe bend, including: a securement structure including a securement device configured to secure a first end of a pipe and a pivot arm coupled to the securement device and configured to pivot about a pivot point to introduce a bend in the pipe; an induction ring configured to heat an annular band of a wall of the pipe; a first quenching ring configured to direct a first quenching fluid toward an outer surface of the heated annular band in the wall of the pipe; a second quenching ring configured to direct a second quenching fluid toward an inner surface of the heated annular band in the wall of the pipe; and a processor configured to control release of the first quenching fluid and the second quenching fluid such that the first quenching fluid reaches the outer surface and the second quenching fluid reaches the inner surface substantially concurrently.