Abstract:
A process for buttwelding metal workpieces (12) having bevelled joint preparations using an automatic GTAW welder (20) using filler wire (32) includes preparing the bevelled workpieces (12) with bevelled joint areas having minimal land thickness at the root extremities; placing the prepared workpiece joint sections together with an open gap between their adjacent root extremities, the gap having a minimum dimension that avoids harmful compression stress between the workpieces due to weld shrinkage and a maximum dimension that avoids filler wire penetration of the gap; fusion welding the open root area of the adjacent workpieces (12) with a root pass weld using an automatic GTAW welder (20) supplied with filler wire (32) and a shield gas including 1 to 10 % hydrogen and the balance inert gas; and then promptly overlaying the root pass weld with at least one additional filler weld pass using an automatic GTAW welder (20) supplied with filler wire (32) and hydrogen-free shield gas.
Abstract:
A friction agitation joining apparatus for joining a plurality of abutted members includes rotatable chucking portions for chucking opposite ends of the abutted members while axially pressing the members, a supporting roller for supporting the members, a driving motor for rotating the abutted members about an axis thereof, and a joining device having a rotatable probe disposed adjacent to an abutted portion of the abutted members. The probe softens and agitates the abutted portion of the abutted members to join them in accordance with a rotation thereof.
Abstract:
The present invention is to provide a stainless steel pipe preventing a gas to be supplied from being contaminated so as to maintain high degree of purity and the stainless steel pipe having a superior corrosion resistance so appropriate as to supply a gas for manufacturing semiconductor. According to the present invention, there are provided a stainless steel pipe and a joining method thereof joined by a butt welding, the stainless steel pipe comprising a joining portion 1 having a butt joining portion 2, the butt joining portion having an outer butt joining portion 2a in an outer wall surface portion 3 joined by a butt welding with penetration welding portion W and, an inner butt joining portion 2b in an inner wall surface portion joined in solid-state without being melted, such that the joining portion comprises the butt joining portion joined by the butt welding with partial penetration.
Abstract:
A heating furnace tube, a method of using the same and a method of manufacturing the same which have been developed with a view to eliminating inconveniences occurring when a carbon-containing fluid is made to flow in the heating furnace tube. The heating furnace tube which comprises a rare earth oxide particle distributed iron alloy containing 17-26 wt.% of Cr and 2-6 wt.% of Al. The method of manufacturing this heating furnace tube which comprises the steps of forming or inserting an insert metal on or into at least one of a joint end portion of one heating furnace tube element and that of the other heating furnace tube element, bringing these two joint end portions into pressure contact with each other directly or via an intermediate member, and diffusion welding the two heating furnace tube elements to each other by heating the insert metal.
Abstract:
A general-purpose jig is provided which includes a base, a locational holding device mounted on the base and having a tripod robot that includes three expansion actuators, and a clamp attached to the locational holding device. The position of the clamp can be changed by changing the length of each of the expansion actuators, depending upon an object to be held, according to a command from a control device. The locational holding device may further include a three-axis rotary unit located between the clamp and the tripod robot. The posture of the clamp can be kept constant by controlling the three-axis rotary unit while the clamp is being moved by the expansion actuators.
Abstract:
Die Erfindung betrifft ein Verfahren sowie eine Vorrichtung zum automatischen Protokollieren der Erstellung eines Rohrnetzes, das durch Verbinden von Rohrteilen hergestellt wird, wobei vor einem Verbindungsvorgang rohrteilspezifische Daten der miteinander zu verschweißenden Rohrteile erfaßt und in einem Speicher zusammen mit einer fortlaufenden, den jeweiligen Verbindungsvorgang eindeutig identifizierenden Kennzeichnung abgelegt werden. Es ist weiterhin vorgesehen, daß für die in einem Verbindungsvorgang miteinander zu verschweißenden Rohrteile des Rohrnetzes jeweils eine zu dem jeweiligen Rohrteil des Rohrnetzes eindeutig gehörende Identifikationskennung generiert wird, die zusammen mit der den Verbindungsvorgang identifizierenden Kennzeichnung in dem Speicher abgelegt wird.
Abstract:
The invention concerns a method for assembling electroconductive parts by electric current heating. Said method is characterised in that it consists in moving forward electrodes (10, 20) with different polarities, towards the parts (30, 40) to be assembled, and in contacting said electrodes with at least one of the parts (30) to be assembled, current being applied to said electrodes (10, 20). Thus, the electroconductive parts (30, 40) are locally heated and assembled by the current flowing through them to pass from one electrode to the other. The invention also concerns a device for implementing said method and its use for assembling hollow parts, tubes or large dimension objects with sheet metal or other hollow parts.
Abstract:
A bonding method capable of easily securing a joint of a two-phase stainless steel having a high strength and a high corrosion resistance comprises the steps of applying cold working to at least a portion of a two-phase stainless steel near a butt and end face to set yield strength of the worked portion to (1.3 x[minimum necessary yield strength for joint] - 10) kgf/mm3, inserting an insert material having a melting point of not higher than 1,150 °C and a thickness of 10 to 80 νm into the joint portion, pressurizing at a pressurizing force of 0.5 to 2 kgf/mm2 while shielded by a nitrogen gas containing 0 to 80 vol % of argon, heating the portion near the joint to a temperature higher than the melting point of the insert material and less than the melting point of a base metal, retaining the temperature for at least 120 seconds, setting the portion to be heated to at least 800 °C or at least 600 °C to not greater than 20 mm or not greater than 40 mm, respectively, setting a cooling rate from the bonding temperature to 400 °C to 50 to 150 °C/sec, and forming the joint having a ferrite ratio of 30 to 70 vol %.
Abstract:
Submerged arc welding is performed in a single layer on both sides so that chemical composition of weld metal produced in seam welding using steel sheet, a low oxygen flux and a low carbon based weld wire provides a structure which contains PWM defined by a formula PWM = Pcm + 3.19Ti - 1.020 and being in the range of 0.18 to 0.33, and in which acicular ferrite has an area ratio of 55 % or more. Further, for an application requiring a crack resistance, submerged arc welding is performed so that in addition to the above condition, chemical composition of weld metal contains Prh defined by a formula Prh = Cr + Cu + Ni + 2Mo + 10V + 7Nb + 5Ti and being 2.8 or less.
Abstract:
A bonded pipe produced by using the liquid phase diffusion process in which the pipe ends of pipes to be bonded are butted with an insert material lower in melting point than the pipe material against each other, wherein the thickness is increased in such a manner that the outside diameter of the butted portion is expanded and the inside diameter thereof is reduced. A method for bonding pipes in which pipe ends of the pipes are butted through an insert material lower in melting point than the pipe material against each other, and the butted portion is heated to and held at a holding temperature higher than the melting point of the insert material, whereby the insert material is diffused in liquid phase into the pipe material, characterized in that at the time point when the outer pipe face temperature of the above-mentioned butted portion reaches a value which is not less than the A1 critical temperature of the pipe material and not more than the holding temperature in the process for raising the temperature of the pipe material, the application of a pressure in the pipe axial direction capable of plastically deforming the butted portion to the above-mentioned butted portion is started to increase the thickness of the butted portion.