摘要:
According to the present invention, penetrators can be adequately determined as flaws. In particular, a welded zone of a pipe is subjected to ultrasonic flaw detection at least in a pipe axial direction, and the quality of the pipe is evaluated using observed values in units of a predetermined area in a pipe thickness direction and the pipe axial direction. The length of one side of the predetermined area is an ultrasound beam width or more and a pipe thickness or less. The quality of the pipe can be evaluated while shifting the predetermined area in the pipe axial direction by using an average value of the observed values within the predetermined area. The length of one side of the predetermined area can be made an ultrasound beam width or more and a pipe thickness or less.
摘要:
A method for manufacturing an electric resistance steel pipe having a good toughness at a welded portion is provided, the method being capable of stably manufacturing an electric resistance welded steel pipe having a desirable toughness at a welded portion although a steel strip serving as a base material has a dimensional variation. Groove shapes and are applied to edges and of an open pipe, an edge shape monitor continuously captures images of the edges and immediately before electric resistance welding, and the captured images are input to an arithmetic processing unit for image processing.
摘要:
The present invention has a structure capable of detecting the scattered-type penetrator having oxides each with the size of several μm sparsely and widely dispersed. Specifically, the structure includes a wave transmission unit 6 for transmitting an ultrasonic wave to the welded surface of the welded portion 2 in a pipe axial direction of the pipe 1 such that the beam width of a transmission beam 8 is brought into a range from 0.5 mm to 2.5 mm, and a wave reception unit 7 for receiving at least a portion of the reflection wave (reception beam 9) at the welded surface. The wave transmission unit 6 and the wave reception unit 7 include transmission/reception units formed of different groups of transducer elements on at least one or more array probes 5 arranged in the circumferential direction of the pipe.
摘要:
An ultrasonic flaw detection is performed to a welded portion 2 of a pipe body 1, a defect detection threshold value is determined based on the signal intensity difference between the total area of the defects existing in the region of an ultrasonic beam on a welded surface and an artificial defect, and a quality control of the pipe body is performed based on the defect detection threshold value. An equivalent defect diameter is determined from the defect density on the welded surface of the welded portion of the pipe body in a pipe axis direction and the area of the ultrasonic beam on the welded surface based on the total area of the defects existing in the region of the ultrasonic beam, and the defect detection threshold value is determined based on the equivalent defect diameter and the signal intensity difference of the artificial defect.
摘要:
According to the present invention, penetrators can be adequately determined as flaws. In particular, a welded zone of a pipe is subjected to ultrasonic flaw detection at least in a pipe axial direction, and the quality of the pipe is evaluated using observed values in units of a predetermined area in a pipe thickness direction and the pipe axial direction. The length of one side of the predetermined area is an ultrasound beam width or more and a pipe thickness or less. The quality of the pipe can be evaluated while shifting the predetermined area in the pipe axial direction by using an average value of the observed values within the predetermined area. The length of one side of the predetermined area can be made an ultrasound beam width or more and a pipe thickness or less.
摘要:
A method for manufacturing an electric resistance steel pipe having a good toughness at a welded portion is provided, the method being capable of stably manufacturing an electric resistance welded steel pipe having a desirable toughness at a welded portion although a steel strip serving as a base material has a dimensional variation. Groove shapes and are applied to edges and of an open pipe, an edge shape monitor continuously captures images of the edges and immediately before electric resistance welding, and the captured images are input to an arithmetic processing unit for image processing.
摘要:
An ultrasonic flaw detection is performed to a welded portion 2 of a pipe body 1, a defect detection threshold value is determined based on the signal intensity difference between the total area of the defects existing in the region of an ultrasonic beam on a welded surface and an artificial defect, and a quality control of the pipe body is performed based on the defect detection threshold value. An equivalent defect diameter is determined from the defect density on the welded surface of the welded portion of the pipe body in a pipe axis direction and the area of the ultrasonic beam on the welded surface based on the total area of the defects existing in the region of the ultrasonic beam, and the defect detection threshold value is determined based on the equivalent defect diameter and the signal intensity difference of the artificial defect.
摘要:
The present invention has a structure capable of detecting the scattered-type penetrator having oxides each with the size of several μm sparsely and widely dispersed. Specifically, the structure includes a wave transmission unit 6 for transmitting an ultrasonic wave to the welded surface of the welded portion 2 in a pipe axial direction of the pipe 1 such that the beam width of a transmission beam 8 is brought into a range from 0.5 mm to 2.5 mm, and a wave reception unit 7 for receiving at least a portion of the reflection wave (reception beam 9) at the welded surface. The wave transmission unit 6 and the wave reception unit 7 include transmission/reception units formed of different groups of transducer elements on at least one or more array probes 5 arranged in the circumferential direction of the pipe.
摘要:
There is provided a method for manufacturing a laser welded steel pipe in which the status of laser welding is accurately assessed, and the assessment is used to modify welding conditions, so that laser welded steel pipes can be manufactured at a high yield rate and in a stable manner. Irradiation point(s) of laser beam(s), with which the longitudinal edges are irradiated from the side of the outer surface, are monitored from the side of the inner surface of an open pipe, and then conditions of welding with the laser beam(s) are assessed to be kept unchanged if any keyhole is found penetrating out of the inner surface of the open pipe, or modified if no keyhole is found penetrating out of the inner surface of the open pipe.
摘要:
There is provided a method for manufacturing a laser welded steel pipe in which the status of laser welding is accurately assessed, and the assessment is used to modify welding conditions, so that laser welded steel pipes can be manufactured at a high yield rate and in a stable manner. Irradiation point(s) of laser beam(s), with which the longitudinal edges are irradiated from the side of the outer surface, are monitored from the side of the inner surface of an open pipe, and then conditions of welding with the laser beam(s) are assessed to be kept unchanged if any keyhole is found penetrating out of the inner surface of the open pipe, or modified if no keyhole is found penetrating out of the inner surface of the open pipe.