Showing papers on "Submerged arc welding published in 1996"

Dilution in single pass arc welds

Abstract: A study was conducted on dilution of single pass arc welds of type 308 stainless steel filler metal deposited onto A36 carbon steel by the plasma arc welding (PAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), and submerged are welding (SAW) processes. Knowledge of the arc and melting efficiency was used in a simple energy balance to develop an expression for dilution as a function of welding variables and thermophysical properties of the filler metal and substrate. Comparison of calculated and experimentally determined dilution values shows the approach provides reasonable predictions of dilution when the melting efficiency can be accurately predicted. The conditions under which such accuracy is obtained are discussed. A diagram is developed from the dilution equation which readily reveals the effect of processing parameters on dilution to aid in parameter optimization.

Optimisation of submerged arc welding process parameters in hardfacing

Abstract: In this paper, a feedforward neural network is used to model submerged arc welding (SAW) processes in hardfacing. The relationships between process parameters (arc current, arc voltage, welding speed, electrode protrusion, and preheat temperature) and welding performance (deposition rate, hardness, and dilution) are established, based on the neural network. A simulated annealing (SA) optimisation algorithm with a performance index is then applied to the neural network for searching the optimal process parameters. Experimental results have shown that welding performance can be enhanced by using this new approach.

Welding process for drawn ARC stud welding

Abstract: The invention relates to a welding process for drawn arc stud welding wherein after ignition of the main current electric arc, the latter's voltage (U) is measured and, depending upon the measured voltage, the current flow of the continued main current electric arc and/or the dipping movement of the parts which are to be welded together, is regulated or controlled.

Gas tungsten arc welding flux

Abstract: An easy to apply flux for increasing the penetration of gas tungsten arc welding of stainless steel substantially independent of flux thickness and variations in composition from heat to heat of stainless steel includes a flux consisting of reagent or laboratory grade TiO or TiO 2 (about 50%), Cr 2 O 3 (about 40%), and SiO 2 (about 10%) in a liquid carrier, preferably of methyl ethyl ketone. The flux is easy to apply, increases penetration of the weld, decreases bead width, and increases weld cross sectional area.

Apparatus for implanting metal ions in metals and ceramics

Abstract: A metal ion implanting apparatus according to the present invention includes a vacuum vessel also serving as an anode, a holder for holding a substrate to be processed, a plurality of arc evaporation sources, a plurality of arc power supplies and a bias power supply. Each of the plurality of arc evaporation sources has a cathode including at least one of metal and a metal compound. The cathode evaporates cathode substance by arc discharge between the cathodes and the vacuum vessel also serving as the anode. Each of the plurality of arc power supplies supply an arc discharge voltage between the cathode of the arc evaporation source corresponding to the arc power supply and the vacuum vessel with the cathode as a negative side. The bias power supply for applying a negative pulse-like bias voltage on a base of a potential of the vacuum vessel to the holder and the substrate held by the holder.

The effect of small changes in flux basicity or the acicular ferrite content and mechanical properties of submerged arc weld metal of Navy HY-100 steel

Abstract: The effect of small differences in flux basicity on the microstructure and mechanical properties of submerged arc weld metal of Navy HY-100 steel has been investigated. It was found that an increase in the flux basicity index from 2.5 to 3.0 (calculated by the formula proposed by Tuliani, Boniszewski and Eaton, 1969, Weld. Met. and Fab. 37 (8): 327-329) led to a decrease in the total oxygen content of the weld metal from 0.034 to 0.027 wt-%. This decrease in weld metal oxygen content led to increasing average nonmetallic inclusion size and an increased propensity for acicular ferrite formation, which were found to increase both the strength and toughness of the weld metal. These results suggest that careful control of the chemistry of both the filler metal and flux is necessary to produce consistently high strength and toughness in weld metal during the submerged arc welding of HY-100 steel.

Method for the plasmic arc-welding of metals

Abstract: The present invention relates to a method for the plasmic welding of metals using a direct-polarity straight electrical arc. This method uses as plasma generating medium the water vapour instantaneously formed in the burner under the action of the thermal energy emitted by the pilot arc on the anode nozzle. The plasmic flow thus generated may be controlled by changing the pilot arc intensity.

Method for welding

Abstract: The method concerns welding of workpieces (10) displaced relative to welding energy sources. These sources comprise at least one high-energy radiation source (11) such as a laser producing a weld seam (12) via formation of a vapour capillary (13), and at least one other energy source (14) producing an electric arc (16) which simultaneously lands within the weld zone (15). During welding the two energy sources are kept apart so that the arc (16) lands either within the joint region heated by the high-energy radiation and not cooled down to the surrounding temperature, or within the joint region not yet undergone welding.

The Effect of Welding Process on the Chi Phase Precipitation in As-welded 317L Weld Metals

Abstract: Three multipass 317L welds were prepared using submerged arc welding (SAW), flux-cored arc welding (FCAW) and manual metal arc welding (MMA), respectively. A microstructural study was undertaken by trepanning 3 mm discs from specific positions in the weld gap, and examining the thinned specimens by transmission electron microscopy (TEM). It was found that, in addition to Chi phase precipitation detected in the regions where overlapping of the welding passes occurred, the large heat input for each welding pass can also induce Chi phase precipitation during the cooling of the welding pool. The mechanical properties showed that there were few differences resulting from the three processes. The intermetallics which formed due to high heat input passes did not appear to have a particularly harmful effect on the mechanical properties.

Weld metal for high strength cr-mo steels and submerged arc welding method

Abstract: (57) [Summary] (Modified) [PROBLEMS] High-strength Cr-Mo steel weld metal effective for welding high-strength Cr-Mo steel (Cr: 2.00 to 3.25 wt%, Mo: 0.90 to 1.20 wt%). And the provision of a submerged arc welding method. A weld metal of high strength Cr-Mo steel is C: 0.04 to 0.14% by weight, Si: 0.05 to 0.40% by weight, M n: 0.50 to 1.30% by weight, Cr: 2.00 to 3.25% by weight, Mo: 0.90 to 1.20% by weight, V: 0.05 to 1.00% by weight, and N: 0.015% by weight or less, the balance consisting of Fe and inevitable impurities, and of the inevitable impurities, P: 0.01 0% by weight or less, Ni: 0.40% by weight or less, Al + Ti: 0.0 18% by weight or less, S: 0.010% by weight or less, Sn: 0.010% by weight or less, As: 0.010% by weight or less, Sb: 0.010% by weight or less, and O: less than 0.045% by weight, and 10 hours at a temperature of 625 ° C. In the residue obtained by electrolytic extraction from only the weld metal raw material after the stress relieving annealing, the content of V is 65 wt% or less, and the (Fe content / Cr content) in the residue is 2.0 or less. is there.

Recycling SAW slag proves reliable and repeatable

Abstract: Submerged arc welding (SAW) slag is recycled by taking the fused part of the slag after welding and processing it in a manner that allows it to be reused for the same SAW operation. This slag recycling process has been around the welding industry for many years, and trial-and-error experimentation through the years has made it a reliable and accepted process. Two major reasons why a welding manufacturer would consider the use of recycled submerged arc welding slag are cost savings and the environment. The cost of processing recycled slag is less than the purchase of new flux from the manufacturer. Many times this can amount to savings of 50% or greater. Savings can also be realized by eliminating the need to collect the slag and have it removed to an approved landfill. Environmentally, recycling slag minimizes the use of nonrenewable resources such as minerals, and it reduces the mass of material that must be sent to a landfill. It should be noted, though, that in most recycling processes there is some loss in weight, and not all the slag is processed into reusable flux. Also, there is magnetic separation during processing in which magnetic impurities are removed and disposedmore » of as waste. An average for this loss is 25% of the total weight processed. To realize all of the advantages of recycling, it is essential that the process is performed properly and according to the standards established by industry. Below are steps required for recycling slag as established by two standards setting organizations.« less

Continuous cathodic Arc sources

Abstract: Publisher Summary All the cathodic arc source components and connections need to be designed to handle the high currents required to sustain an arc. Cathode spots (CS) spontaneously extinguish, and can be characterized by an average lifetime, which increases with the arc current. The lifetime is a strong function of cathode material, and is generally longer for the more volatile materials. In addition, the lifetime is a function of the electrical circuit, electrode geometry, and applied magnetic field. As a rule of thumb, the arc current for sustained arcing should be at least as large as the cathode spot splitting current. The energy of the vacuum arc discharge is concentrated in the CS region where practically all the drop of the applied voltage occurs. This energy is removed conductively from the cathode, is spent on electron emission, and leaves the near-cathode region in the kinetic energies of ions and in the thermal energy of electrons moving to the anode. The chapter discusses three categories of control strategies for confining the arc spot to the desired cathode surface. The first two utilize a magnetic field and the acute-angle rule for arc spot drift. The third simply covers all but the desired cathode surface with an insulating material, or electrically isolated metal shields. It is mentioned that coating systems based on the cathodic arc have been used successfully in a great number of applications.

Method for repairing gas turbine blade

Abstract: PROBLEM TO BE SOLVED: To prevent development of a weld crack and to improve soundness of a repaired part in repairing by cladding by welding the deteriorated part at the tip end of a gas turbine blade, by flowing a fluid into the cooling ventilating hole inside the blade, and welding while cooling or heating in accordance with the kinds of repair, composition of the blade material, etc. SOLUTION: A cladding by welding zone 3 is formed by generating arc 6 between the deteriorated part 2 at the tip end of a gas turbine blade and a welding electrode 5. While the welding method can use any welding heat source such as TIG arc, plasma arc and laser, a gas or liquid inlet port 8 connected to a ventilating hole in the blade is provided in the lower end of the blade 1 at the time of welding, so that a cooling gas, heating gas or cooling water is supplied. In the heat affected zone of the base material at the time of welding, expansion and contraction incident to the heat history causes a tensile stress; hence, the heating or cooling speed of the heat affected part is adjusted by the fluid flowing in the ventilating hole in the gas turbine blade 1, relaxing the tensile stress and suppressing the development of a high temperature crack. COPYRIGHT: (C)1998,JPO

Method of igniting a welding arc

Abstract: A method is indicated for igniting a welding arc between a fixed electrode and a metal workpiece to be welded, whereby a covering protective gas is supplied by a nozzle that extends into the welding area. Before a welding power source is switched on for the welding arc, an auxiliary arc supplied by an auxiliary power source is ignited, which ignites the welding arc after the welding power source is switched on. To better ionize the welding area and ensure the ignition of the auxiliary welding arc, a high-frequency electric arc is produced in the welding area between the nozzle and the workpiece by means of a pulse generator which produces high-frequency high-voltage pulses.

A microstructural study of phosphorus segregation and intergranular fracture in neutron irradiated submerged-arc welds

Abstract: Accelerated irradiation experiments have been carried out on submerged-arc welds to obtain validation of trend curves built up from surveillance results. This was done by withdrawing surveillance specimens and re-irradiating them in higher flux positions. One batch, from weld HS, showed a significantly higher increase in the Charpy {Delta}T{sub 40J} value than that for weld LS at a similar dose. Work done to explain this difference is described in this paper. Selected Charpy specimens were examined using a shielded scanning electron microscope to determine the fracture modes present. Regions of mixed cleavage, micro-void coalescence (MVC) and intergranular failure (IGF) were found on HS weld specimens fractured in the transition region. The IFG was confined to certain regions within each weld bead. Significantly less IGF was found on LS weld specimens. Sub-fracture surface matchstick specimens were removed from embrittled regions and fractured within a scanning Auger microscope. IGF occurred in these specimens, and phosphorus was found to be the main grain boundary segregant. The levels of phosphorus increased with increasing neutron dose. No other embrittling element was consistently found at any significant level, but carbon was also found on grain boundary surfaces in some cases. The grain boundary coverage of phosphorusmore » was determined for each weld at several neutron dose levels.« less

Method for welding steel, and manufacture of steel

Abstract: PURPOSE: To improve the efficiency of the arc welding of steel, and to provide an excellent large steel structure member with improved quality of the heat- affected zone. CONSTITUTION: The steel of 800-1400 deg.C in temperature and 10-200mm in thickness is welded by the gas shielded arc welding method or the submerged arc welding method with the condition of 10-60mm in the groove root face, and 3-30kJ/mm in the heat input. The steel of high temperature can be efficiently welded by the large heat input welding, and the amount of the welding material can be reduced. The steel whose weld zone is assimilated to the base metal can be obtained by rolling the welded steel.

Method of fabricating high strength and high toughness large-diameter welded steel pipe

Abstract: Utilizing a low-oxygen welding flux, and a low carbon welding wire, seam welding is conducted by submerged arc welding so that the resulting weld metal has a chemical composition, in which P WM value defined as below is in a range of from 0.18 to 0.33, and a micro-structure containing acicular ferrite not less than 55% by area ratio: P.sub.WM =P.sub.cm +3.19Ti-1.020 where, P.sub.cm =C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5B Furthermore, when cracking resistance is required, submerged arc welding is conducted such that the chemical composition of the weld metal satisfies P rh value of less than 2.8, in addition to fulfilling the above conditions: P.sub.cm =C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5B.

Automatic tracking device for longitudinal ring clearence of submerged-arc welding barrel

Abstract: The utility model relates to an automatic tracking device for longitudinal ring clearances of a submerged-arc welding barrel. A mechanical-electrical integration system controlled by a closed ring is composed of a contact tracking sensor 7, a microcomputer control system 8, a repeating motor 2, a driving power for the repeating motor, a three-dimensional follower, and a submerged-arc welding head section 6. Different positions of the contact tracking sensor 7 are adaptable to various welding grooves to finish the submerged-arc weld of the longitudinal ring clearances inside and outside the barrel. The inside diameter of the minimum workpiece of inner longitudinal ring clearances in working condition is 650 mm, and a tracking error is 0.5 mm. Each dimensional regulating range of the three-dimensional follower is bigger than 120 mm. The automatic tracking device for longitudinal ring clearances of a submerged-arc welding barrel adopts the repeating motor to drive an adjusting mechanism directly, and adopts a unique roller guide mechanism and a linear sliding bearing guide mechanism. The automatic tracking device for longitudinal ring clearances of a submerged-arc welding barrel has the advantages of unique structure, long service life, convenient regulation, high precision, small size, low resistance, stable adjustment, and long term work. The automatic tracking device for longitudinal ring clearances of a submerged-arc welding barrel solves the problem of the ring clearances of a barrel unable to be tracked. Devices of the automatic tracking device for longitudinal ring clearances of a submerged-arc welding barrel can also be used in other welding methods.

Shielding gas and heat transfer effeciency in plasma arc welding

Abstract: Variable polarity plasma arc welding is widely used in the aerospace industry for producing high-quality welds on aluminum. In plasma welding the arc is produced in a narrow stream of plasma gas while workpiece shielding is accomplished by a lower velocity but higher flow rate stream of shielding gas that surrounds the arc. This paper will show that on aluminum welds both the melt zone and the heat-affected zone are appreciably decreased by this flow of shielding gas. Moreover, the amount of cooling is changed by the detailed shape of this flow as well as the flow rate. On the other hand, it will be shown that excessively high shielding flow rates can cause undercutting from contamination in the shielding gas.

Submerged arc welding method for one side surface

Abstract: PURPOSE: To obtain the sound penetration bead even in a high speed welding by improving particularly backing flux in the submerged arc welding for the one side surface in a high speed. CONSTITUTION: The submerged arc welding method for one side surface uses a copper plate and the flux as the backing and three or more pieces of the electrodes. The wire diameter of the first electrode is made to be 4.0-4.8mm and the wire diameter of the second electrode followed to the first electrode is made to be 4.8-6.4mm. The current of the first electrode is 1400-1800 A, and at the time of setting of I1 for the current of the first electrode and I for the second electrode these currents are made to be 0.4-I1 bulk density is spread on the steel plate at 4-6mm thickness and welded at 1.0-2.0m/min speed. The inclination of the first electrode is made to be 0-15 deg. retreating angle and the inclination of the second electrode is made to be 0-15 deg. advancing angle.

Process monitoring and on-line modelling of the gas metal arc welding process

Abstract: PROCESS MONITORING AND ON-LINE MODELING OF THE GAS METAL ARC WELDING PROCESS This Abstract is brief description o f a thesis on the development o f methods for the Process Monitoring and On-line Modeling o f the Gas Metal Arc Welding Process (GMAW). Progress in development o f Advanced Process and Equipment for GMAW, especially in Automated and Mechanised Welding, requires clear understanding o f the physical phenomena o f the Welding Process [1]. The objective o f this thesis is to design and develop modem experimental facilities capable o f providing instrumentation and photography to record welding phenomena, so as to allow a thorough study o f die physical welding processes. The thesis initially describes the development o f an Experimental Facility for Monitoring die Gas Metal Arc Welding (GMAW) Process. The Facility described consists o f : a) Weld Testing Facilities. b) A Physical Testbed with a Weld Table moving under a stationary GMAW Gun. c) Electronic Monitoring o f the GMAW Parameters including Weld Voltage (V), Weld Current (I), Wire Feed Rate(WFR) and Weld Travel Speed (TS). d) Computer Control o f GMAW Parameters including Weld Voltage, Wire Feed Rate and Weld Travel Speed. e) Weld Visualisation using High Speed Photography with a Communications Link from the High Speed Camera to the Electronic Monitoring System allowing the Camera, when it commences its diming run, to trigger the Electronic Monitoring System, thereby enabling time-correlated Electronic Data and Visual Images to be obtained. The thesis next describes in detail the Weld Testbed and Electronic Monitoring System in terms o f Electronic Hardware, Software Algorithms for Weld Monitoring, Algorithms for Weld Parameter Control and two Graphical User Interface (GUI’s) Packages developed for the Viewing and Analysis o f Weld Data. These Software Packages are: a) ‘Shortmon’: A package for Viewing and Analysing the Parameter Traces o f short bursts o f Welding Data ( < 2 seconds). b) ‘Longmoir : A package for Viewing and Analysing the behaviour and stability o f Weld Parameter Settings over longer welding periods (up to 120 seconds). Both o f the above described Packages also include Computer Controlled Setting o f Weld Parameters. ‘Longmon’ also allows in-weld alteration o f Weld Parameters thus enabling the effects o f Weld Parameter variation to be studied. The verifification o f the MWEF as a facility for GMAW Control Strategy development was achieved through a series o f experimentation in which process irregularities were induced and monitored in Real-time. The next Stage o f the thesis describes the development o f a Graphical User Interface (GUI) for On-line Modeling o f the Welding Process in a single weld run utilising Weld Parameter Feedback for a range o f Computer Controlled Weld Parameter Settings. An important research interest is the development o f Strategies and Models for die effective Real-time Control o f the Welding Gun Standoff (L) (also often referred to as ‘Contact-tip to Workpiece Distance’). The On-line Modeling Package has therefore been initially developed to generate Least-Squares Models of: I = ffV,W FR,L) and also L = f(V,I,WFR) which are intended for use as Real-time Estimators for Current and Standoff Control. This work is funded by die Cooperative Research Centre (CRC) for Materials Welding and Joining as part o f Project 93/12 which is a collaborative research effort in the area o f Welding Automation between the University o f Wollongong, The University o f Sydney and the CSIRO Division o f Applied Physics (Sydney). Please Note that Welding Visualisation with High Speed Photography was developed by Dr. Wee King Soh and Mr. Heman Ratio whilst the Welding Testbed and the Electronic Monitoring and Control o f the Welding Process was developed by the Author under the supervision o f Professor Michael W est

Welding low thermal expansion alloys for aircraft composite tooling

Abstract: To save weight in commercial aircraft and help military jets evade radar detection, aircraft designers specify the use of composite materials. These new designs have resulted in the use of low-expansion materials for aircraft composite tooling because they keep their dimensions during curing. However, the Fe-Ni low-expansion alloys have long presented problems during welding. When matching composition filler metals were used to match the coefficient of thermal expansion (CTE), cracking problems occurred. Filler metal compositional changes to eliminate cracking disturbed the CTE match of the weld with the base metal. A recently developed welding consumable appears to eliminate those problems. With the development of this new filler metal, high-quality crack-free welds can now be obtained with high deposition rates. Since there is a more closely-matched CTE, weldments and tools should provide longer service because of minimal effects from thermal fatigue. There have been reports of vacuum leaks in tools using the Mn-Ti filler metal, which could be directly attributable to the mismatching CTE. Using Nilo filler metal CF36 eliminates weld hot-cracking problems and provides good thermal fatigue resistance due to its excellent CTE match with the base metal, Nilo alloy 36.

Submerged arc welding method of high current density

Abstract: PROBLEM TO BE SOLVED: To reduce fusion failure by specifying a welding current density with respect to a welding wire diameter in the submerged arc welding of a carbon steel plate. SOLUTION: In the submerged arc welding of the carbon steel plate, welding is performed by setting the welding current density to 130 to 165A/mm 2 for a welding wire diameter 2.4mm, 80 to 105A/mm 2 for a welding wire diameter 3.2mm and 60 to 75A/mm 2 for a welding wire diameter 4.0mm. The welding current density is a value obtained by dividing a welding current value by a cross-sectional area of a welding wire. Since a current to be used is high, a depth of penetration can be properly controlled, and the fusion failure can be remarkably reduced. COPYRIGHT: (C)1998,JPO

Apparatus for controlling arc deflection in an arc furnace

Abstract: An arc control apparatus for a DC arc furnace provides an additional magnetic field which prevents a discharged arc from shifting outward at an arc generating point due to the influences of a magnetic field generated by a feeder circuit, thus directing the arc discharge vertically downward. The arc control apparatus includes an arc furnace in which an object to be melted is disposed. A movable electrode is disposed in the arc furnace for movement relative to the object. A feeder circuit including a power supply and a feeding conductor is connected to the movable electrode and the arc furnace for supplying a voltage therebetween from the power supply through the feeding conductor to generate an arc whereby the object is dissolved. An auxiliary coil is disposed outside and in the vicinity of the arc furnace and connected to the feeder circuit for generating a counter magnetic field in a direction to cancel a magnetic field which is generated at a point of generation of the arc by means of the feeder circuit.

A simulation model for estimating probabilities of defects in welds

Abstract: In recent work for the US Nuclear Regulatory Commission in collaboration with Battelle Pacific Northwest National Laboratory, Rolls-Royce and Associates, Ltd., has adapted an existing model for piping welds to address welds in reactor pressure vessels. This paper describes the flaw estimation methodology as it applies to flaws in reactor pressure vessel welds (but not flaws in base metal or flaws associated with the cladding process). Details of the associated computer software (RR-PRODIGAL) are provided. The approach uses expert elicitation and mathematical modeling to simulate the steps in manufacturing a weld and the errors that lead to different types of weld defects. The defects that may initiate in weld beads include center cracks, lack of fusion, slag, pores with tails, and cracks in heat affected zones. Various welding processes are addressed including submerged metal arc welding. The model simulates the effects of both radiographic and dye penetrant surface inspections. Output from the simulation gives occurrence frequencies for defects as a function of both flaw size and flaw location (surface connected and buried flaws). Numerical results are presented to show the effects of submerged metal arc versus manual metal arc weld processes.

Three electrode two layer submerged arc welding of thick plate

Abstract: PURPOSE: To achieve high efficiency welding by executing large heat input two layer/two pass welding of a thick plate exceeding 50mm thickness. CONSTITUTION: In executing full penetration one side three electrode submerged arc welding to a thick plate with two passes, welding of a second layer is executed while satisfying conditions in the following, (1) pole distance (dNT) (mm) between M pole and T pole; 30-130, (2) M pole current/T pole current; 0.5-1.2, (3) shortest distance (b) mm on base material surface from groove end of one side to M pole end part; t/9-t/3, (4) shortest distance (c) (mm) on base material surface from groove end of other side to T pole end part; t/8-t/2, here (t) is a groove width (mm) on base material surface.

Two-electrode horizontal fillet welding submerged arc welding method for t-joint

Abstract: PURPOSE: To provide a two-electrode horizontal fillet welding submerged arc welding method of a T-joint to manufacture a welded wide flange shape with excellent efficiency by achieving the fillet welding under the prescribed welding conditions with a web in the horizontal position. CONSTITUTION: In a single layer fillet welding of a T-joint where a web is a thick steel prattle, a web 1 is in the horizontal position, and the fillet welding is achieved under the conditions where the diameter of L-pole wire: 3.2-6.4mm, the diameter of T-pole wire: 3.2-7.0mm, the ratio of the L-pole current to the T-pole current: 0.6-1.0, the voltage of L-pole: VL<=45V, the voltage of T-pole: VT<=50V, the angle of tiltation (a) of l,pole electrode: 3-30 deg., the angle of tiltation (b) of T-pole: 3-35 deg., the angle (c) of L-pole electrode: -10 to +10 deg., the angle (d) of tiltation of T-pole electrode: 0-30 deg., the distance between L-pole and T-pole: 10-120mm, the shortest distance between the L-pole and the flange: 0-10mm, and the shortest distance between the T-pole and the flange: 1-13mm. The web 1 is the thick steel plate exceeding 16mm and up to 32mm in thickness, and the fillet welding is achieved by the partial penetration method without groove.

Production of clad welded steel pipe

Abstract: PURPOSE: To provide a process for efficient production of a clad welded steel pipe having decreased defects. CONSTITUTION: This method for producing the clad welded steel pipe by working a clad steel plate to a pipe stock shape and welding a base metal part of carbon steel, etc., and a clad metal part of a high alloy, etc., to the pipe stock, in which method the welding on the clad metal part side of the base metal part is executed by using a flux having a groove angle of 90 to 120 deg. and bulk density of and by a submerged arc welding method specifying the welding speed, welding current value and welding voltage to optimum ranges according to the number of electrodes. As a result, smooth and good weld beads free from slag inclusion are obtd. without inducing the contamination of the base metal part and the clad metal parts with each other at the time of welding.