Bead Appearance Research Articles

ショッププライマー塗装鋼の溶接性

The object of this study was to investigate the effect of coating thickness on the weldability of the steel coated with a shop primer, and finding a shop primer for giving the highest weldability of steel in the T-type fillet welding under the worst welding conditions.Experiments were conducted on 11 kinds of shop primers giving high weldability of steel in butt welding.The shop primers employed were as follows: 5 kinds of organic zinc primers, 4 kinds of non-zinc primers, and each one kind of inorganic zinc primer and wash primer.The coating thicknesses of primers were about 15, 30, and 60μ. Blank tests were conducted on uncoated steel plates for reference.Arc welding process was conducted with a gravity type arc welder by T-type fillet welding.Welding operation test, bead appearance test, and T-type fillet weld bending test were conducted on these test pieces.The results obtained were as follows:(1) The arc of welding was more difficult to be generated with the increase in coating thickness of primer. The generation became impossible at more than about 30μ in non-zinc primers and a wash primer. Therefore, it was reguired to remove the primers in the arc starting zones for the welding of these coated steels.(2) The removal of spatter was easier with the increase in coating thickness of primer, but the arc stability, slag detachability, bead appearance, etc. became worse. As the result, the crack sensitivity in bending test became higher. In particular, a kind of organic zinc primer prepared by the combination of an epoxy resin and minium, and a kind of non-zinc primer containing a large quantity of chrome yellow displayed such a tendency.(3) The welding speed and deposition rate were lower with the increase in coating thickness of primer. In particular, non-zinc primers displayed such a tendency.(4) In general, the weldability of these steels coated with primers seemed to turn lower at about 30μ of coating thickness in T-type fillet welding process. Therefore, sufficient control of coating thickness of primer was needed in shop coating.

水中溶接に関する研究(第1報)

Underwater welding was experimentally carried out in a water box by coated electrodes and semiautomatic CO2 welding. And It was investigated the occurrence of blowhole was affected by various welding parameters.The following results were obtained:1) Sound deposited metal and welded joints were obtained under flat, horizontal and vertical positions from every coated electrode except the low hydrogen type one. Kinds of power sources and water proofing coatings of electrodes had no special effect on appearance and soundness of bead.2) Welded joints by coated electrodes were superior in tensile strength but inferior in ductility to the mild steel base metal.3) It was difficult to get a sound weld metal by low hydrogen type electrode under water. Blowholes in weld metal were remarkable in all welding current and arc voltage ranges.4) It was also considerably difficult to obtain a weld metal quite free from blowholes by underwater semiautomatic CO2 welding.

Fibromuscular hyperplasia of the carotid artery; in a case associated with an arteriovenous malformation.

FIBROMUSCULAR hyperplasia is an intrinsic arterial lesion which often has a characteristic string of beads appearance on angiograms. Most commonly found in the renal arteries of young and middle aged female patients, it is felt to be the most common form of several related conditions, including periarterial stenosis and internal stenosis and classified under the term fibrous dysplasia. Harrison et al 1 describe them as a group of related idiopathic nonarteriosclerotic arterial lesions producing disruptive and hyperplastic changes in the arterial wall, particularly involving the elastica, smooth muscle, and elements of the media, which result in various types of stenosis with or without aneurysm. The relative infrequency of fibromuscular hyperplasia in the cranial vessels is reflected by the finding of Houser and Baker 2 of 16 cases in 5,000 angiograms. In fact, there have only been a few reports of the disease in the carotid arteries

サブマージアーク・タンデム方式におけるビード形成に関する研究

Studies on the bead formation have been carried out in the case of two electrodes submerged arc tandem method.It has been made clear that two arcs have their own functions in bead formation; that is, the lead-arc has the function of Digging the base-metal and the trial one that of Regulating the bead appearance.Taking these functions into consideration, the possibility of high speed welding has been examined with five kinds of tandem methods.As the result of it, it is found out that the deflection of the trail arc chiefly influences the bead appearance, and that the bead appearance is beautiful even in the high speed range if only the trail arc is deflected in the welding direction.When an alternating current is used, the phase angle between two arc-currents is very important, and when a direct current is used, attention must be paid to the earth position; that is, start side or end side.It means that the bead appearance is governed by the interaction between the magnetic fields of the arcs and the current through the base metal.

ショッププライマーを塗装した鋼の溶接性, ガス切断性について

In order to develop a shop primer for giving the highest weldability and gas-cutting ability of steels, experiments were conducted on the steel coated with various kinds of shop primers.The employed shop primers included 70 kinds. Their groups and kinds were as follows:20 kinds……prepared by the combinations of various resins and pigments22 kinds……prepared by the combinations of phenoxy resins and various pigments6 kinds……prepared by various PVC (volume concentration of pigment) value4 kinds……prepared by various compositions of solvents6 kinds……for various coating thicknesses12 kinds……for several commercial shop primersThe coating thickness of primers was about 25μ, except for the above 6 kinds which were in the range of 10-40μ.Blank tests were conducted for reference on the uncoate3 steel.Arc welding was carried out by manual and butt weld.Welding usability test and bead appearance test, X-ray inspection, tension test, roller bending test of the weld zone, and gas cutting ability test were carried out on these test pieces.The results obtained were as follows:1) Phenoxy resins showed considerably superior weldability of steel; but chlorinated rubber resins, acrylic resins, and pigment of lead type were inferior. Generally speaking, the effects of shop primers on weldability of steel seemed to be somewhat different according to the combinations between resins and pigments.2) Non zinc shop primers, D and E, showed the highest weldability and cutting ability among 70 kinds of the primers.3) The commercial shop primers showed superior weldability to trial primers.4) Chlorinated rubber resins showed the lowest gas cutting ability. Phenoxy, alkyd, and ketone resins showed fairly high cutting ability.5) The commercial shop primers, except for those of zinc rich type, showed fairly high gascutting ability.6) The effects of coating thickness of weld on welding and gas-cutting were not observed in such a narrow range of 10-40μ.

TIGアークにおけるビード形成におよぼす磁場の影響

Experiments show that bead appearance becomes discontinuous (abnormal) when welding velocity increases over a certain high limit, other variables (welding current, arc voltage, etc.) being kept constant.Hicken and Jackson report that the bead appearance becomes continuous when arc is deflected to welding direction with use of transverse magnetic field.We have been interested in the above-mentioned experimental results.In order to find out their important factors, using transverse or longitudinal magnetic field, we have observed in detail the phenomena which have been brought about when all welds are being deposited on the mild steel with TIG arc.As the result, we have found out the following facts.(A) When magnetic field is not applied, molten metal is pushed down with plasma jet and molten layer in the bottom of pool becomes gradually thin in proportion to the increase of welding velocity. This thin molten layer tends to solidify instantly when the arc foot moves sometimes to another spot according to the arc character. This results in the formation of a naked solid surface in the bottom of the pool. This naked solid surface disturbs the free flow of the molten metal in the pool and the bead becomes discontinuous.(B) When arc is deflected to welding direction with use of transverse magnetic field, molten metal is pushed forward and the molten pool is always full of molten metal. (See Fig. 6 (a))(C) When magnetic direction is reversed, molten metal is positively blown away with plasma jet.This causes the formation of a naked solid surface in the pool more easily than (B) and consequently the bead becomes discontinuous. (See Fig. 6 (b))(D) When the longitudinal magnetic field is applied, molten metal rotates in the pool and so be naked solid surface is covered with molten metal.In the case of (A), bead appearance begins to become abnormal at the velocity of 200 mm/min.In the case of (B), bead appearance is always continuous for all the velocities in our experimental range.In the case of (C), bead appearance begins to become abnormal at the velocity of 120 mm/min.In the case of (D), bead appearance begins to become abnormal at the velocity of 280 mm/min.After all, it has become obvious that the naked solid surface causes the bead to be abnormal.

Addition of nitrogen to shield gas (He) in MIG welding of aluminum alloys

In the previous paper it was reported that grains in bead of MIG welded aluminum alloys were refined and welding cracks were decreased by the addition of nitrogen to argon gas.However, the welding usability was lowered by the addition of nitrogen; i.e., the stability of arc was made poor and the appearance of bead was made irregular.In order to avoid the above defects, He-N2 mixed gas was used for MIG welding of the specimens instead of Ar-N2 mixed gas.The following results were obtained.(1) Arc was made more stable and the appearance of bead was also made better in He-N2 than in Ar-N2 gas.(2) The depth of penetration was increased by the addition of nitrogen.(3) The grains in bead were refined by MIG welding in He-N2 as well as in Ar-N2 gas, when Al-Zn-Mg alloys containing small amounts of titanium and zirconium (which are powerful elements for grain refining) were used for the parent metal.(4) Welding cracks were decreased in inert gases containing nitrogen for the welding of Al-Zn-Mg alloys.

高張力鋼の溶接性に対するショッププライマーの影響について

The effects of Shop Primer on the weldability of high tension steel were investigated. The Shop Primer employed included 3 kinds; i.e., an organic zinc primer and 2 kinds of wash primer, and the thickness of the coated layers was about 10 and 20μ, respectively. Concurrently, the weldability of uncoated high tension steel was also investigated. The arc welding was processed by manual weld in each case.On each of these specimens, examinations were made for welding workability, bead appearance, X-ray transmission, analysis of zinc content in the deposited metal, X-ray diffraction of coated bead slag, and macro- and micro-structure and static mechanical strength of the weld zone.The results were as follows:(1) Organic zinc primer or wash primer could satisfactory be used for priming coat, when the welding was processed under the following proper conditions.a) The steel plate was properly beveled.b) The spacing between included angles was considerable.c) The arc length was properly maintained.(2) It seems that organic zinc primer had the most excellent weldability among various types of Shop Primer with respect to rust preventive and corrosion resistant properties. Accordingly, it was concluded to be an effective Shop Primer.

Preparation of Metallic Promethium

A method is described for purification of Pm by reduction of PmF/sub 3/ in vacuo. Processed Pm from the Isotopes Division of Oak Ridge National Laboratory, used as starting material, contained approximates 50 C (60 mg) of Pm/ sup 147/together with about 50 mg Sm, 40 mg Nd, and about 7 mg Am /sup 241/. The lanthanides were separted on Dowex 50 x 12 by elution with 0.5M ammonium alpha - hydroxyisobutyrate at pH 3.5 and 87 deg C. The Am was separated by absorption on Dowex 1 x 10 and elution of the Pm with SM ammonium thiocyanate. After this separation, the purplish pink solution of Pma in HNO/sub 3/ still contained about 17 C of Pm/sup 147/, and aliquot portions, each of 100 mu l, were removed from it. The purplish pink PmF/sub 3/ was precipitated with HF, washed several times with distilled water, centrifuged, and the supernatant solution pipetted off. After drying for two days over P/sub 2/O/sub 5/, the PmF/sub 3/ had shrunk to a compact pellet. The pellet was transferred to the inner basket of a tantalum crucible system, and approximates 10 times its wt of pure Li was placed in the outer crucible; themore » whole unit was then closed with a tantalum stopper and suspended in the container vessel of a vacuum manifold. At 2.7 x 10/sup -6/ mm Hg pressure the system was heated by means of an induction heater. At 750 deg C, excess Li effused from the crucible system. The crucible was then maintained for periods of 2 min each at 800 deg , 980 deg , and 1090 deg C, and then cooled to room temperature over 1 hr and examined under the microscope. Promethium metal had separated as a solid bead which had fused onto the tantalum wires of the inner container and which had the appearance of a Nd bead obtained under similar conditions. lts mp was 1080 plus or minus 10 deg C. Because of its high radioactivity (940 mC/mg), a glovebox was used for high vacuum operations involving Pm. (BBB)« less

Årupgårdfundet

The Årupgård HoardIn October 1958, in the course of gravel digging at Årupgård near Horsens in Jutland, the pieces of a pottery vessel containing amber beads and copper ornaments were found. The potsherds could be reconstructed, to form an undecorated lugged vase with 5 lugs placed low on the body (Fig. 2). Similar lugged vases are known in Denmark, from settlement sites and peat-bog deposits, but they vary greatly in size, ornamentation and number of lugs 1)-12). Apart from a single lugged vase from Rügen 13) no similar vases are known outside Denmark. The Årupgård vase must have been produced by non-megalithic funnelbeaker people of Jutland in Early Neolithic Period C or in the beginning of the Middle Neolithic 18) 19).The amber in the hoard consists of 271 beads and 177 fragments. They can be divided into unformed lumps with the appearance of natural amber, and cylindrical and conical beads where the amber has been shaped to these forms. Their appearance is shown in Table 1 and Figs. 3-6. All types of beads here represented are known from Early Neolithic times in Denmark 21). To judge by the marks of wear the beads have formed parts of necklaces. 57 amber hoards from this prehistoric period are known on Danish soil, containing greatly varying numbers of beads 23).The copper objects comprise 2 spiral finger-rings, 2 long spiral cylinders, 3 small spiral cylinders and one cylinder of copper sheeting (Fig. 7). In the latter was found pollen susceptible to analysis (p. 17). With its large proportion of Plantago lanceolata this pollen shows that the wearer of the copper ornament spent his (or her) time mainly in a landscape of common-land type.While the pottery vessel and the amber beads must have been produced in Denmark the copper ornaments must have been imported. Of objects of copper about fifty axes are known from unassociated finds on Danish soil 38). At Bygholm, only 4 kms. from Årupgård, the wellknown Bygholm hoard was discovered in 1924 (Fig. 8). At Søby Heath a copper axe and a spiral ribbon of the same metal have been excavated 40), from the Barkær settlement some small fragments of copper sheeting are known 41), and in a grave at Salten the remains of a disc-shaped copper ornament were found 42). The Salten ornament, the Barkær copper and the Årupgård ornaments belong to the non-megalitihic Period C (or perhaps D), and the Bygholm board must be attributed to the Late Dolmen Period 45) or the beginning of the Passage-Grave Period 46), and is thus contemporary with or later than the Årupgård hoard.Copper spiral rings and cylinders of the Årupgård type have been found at many points in Europe, and from the Early Neolithic Period they are particularly known from the Alpine and Danube cultures 48). Spiral rings of copper do not appear to occur within the area of the Southwest European cultures 51). During the following periods spiral rings and cylinders spread over Europe, first in copper and later in bronze, and occur commonly throughout the Bronze Age 52). At Riesebusch, Skarbnice and Stollhof copper hoards have been found which link the Årupgård and Bygholm hoards together typologically. Spectroscopic analysis (Table 2) shows that the copper from Årupgård, Bygholm and Riesebusch originally came from the copper mines at Zwickau, as a similar copper ore with arsenic content can be found there 58). The Årupgård ornaments may have been made at many different places in Europe, though probably within the Alpine or Danube cultures. In this connection attention is particularly paid to the Theiss variants in Saxony, Thuringia, Silecia, Bohemia, Moravia, Poland and Hungary 61). The copper objects must have been conveyed by river routes to the Baltic, and then along the coast to Horsens Fjord 68) 69). They may there have been traded for amber and flint 70) 71). The hoard may have belonged either to a man or a woman 76), and can be either a concealed depot or a votive offering. Bent Sylvest and Inger Sylvest.

塗装面に対する熔接施工について

In order to investigate the weldability of mild steel coated with various paints, we made some experiments and obtained the following summaries ;1. In manual welding (low hydrogen type and ilmenite type) and semi-automatic welding (high iron powder type), several kinds of paints, including wash primer, iron oxide, zinc chromate and new paint (oleoresinous) whose film thickness not exceeding 2 mils, had little effect on the ease of arc start, arc stability, bead appearance and on the result of the radiographic inspection.2. Every paint film having thickness of not less than 5 mils had significant effect on the weldability of mild steel.3. Paint films were very harmful in submerged arc welding, irrespective of kinds of paints or film thickness.4. According to the Lehigh restraint tests, a 2-mil coat of wash primer and new paint (oleoresinous) had no effect but iron oxide and zinc chromate caused a slight rise of crack sensitivity.5. 2-mil coat of four kinds of above-mentioned paints has no detrimental effect on V-notch Charpy impact values of deposited metals, though wash primer lowered them a little.6. Viewing from what we stated above, we may say that wash primer, iron oxide, zinc chromate and new paint (oleoresinous) films, not exceeding a film thickness of 2 mils, have no detrimental effect on the weldability of mild steel in manual welding and semi-automatic welding.

鋼の特殊潜弧熔接

Coated electrodes were laid down along weld seams, over which granular flux was heaped, and arc welding was performed automatically. Coated electrodes used are of the types D4301 (ilmenite), D4312 (rutile), D4313 (rutile), D4316 (lime basic) and D4320 (iron oxide). Two types of granular flux were used.External appearance and radiograph of a weld bead was examined and compared with each other. D4316electrodes gave most beautiful bead free from any type of weld defects.Burn-off rates of electrodes, consumption of granular flux and penetration depth of weld beads were measured. Tensile tests of cross fillet-welded specimens were carried out.

多電極自動熔接におけるArc現象について(第1報)

In the submerged arc welding to analyze the transfer phenomenon of the metal (1) and the fo mation of the crater by arc in the covered flux (2), the X-ray radio photograph and oscilgraphic photograph tests are applied to the single electrode and multiple electrode welding. In taking the X-ray, the constant potential 280 KVP capacity to be used and the selected shutter speed of the photograph for transfering the metal and formation of the crater by arc to be 1/900 sec. and 1/50 sec. respectively. The A.C. welder and D.C. constant potential welder are to be used.Judging from the X-ray radio and oscilograph tests being practiced it is presumed that the transfering metal of the submerged arc welding is transmitted (dropped) irregularly as the fine grain. And the condition of the crater which is made by arc in other works the shape of the weld puddle and the relative positions between the weld puddles and electrodes differ depending upon the welding current, speed, voltage and electrode distance in the case of the multiple electrode process. It also confirms the relation between the shape of the weld puddle and bead appearance and penetration as well as the distribution of the electric current in the parallel connection welding method.

炭酸ガス関口線材アーク熔接法について(第5報)

The C. S. Arc Welding Process does not produce so much quantity of slag as the submerged arc welding process or manual arc welding process with coated electrode, because this process needs no flux. But since the filler wire for this process contains much quantities of deoxidizers, the quantity of deoxi-dation-product is comparatively large. And the product, rised up from the molten weld metal, remains partly on the surface of bead.In case of the multi-pass-welding of thick plates, it is desirable to remove completely this small amount of slag. This slag can be removed by a chipping-hammer, and it is not easy to remove the slag by wire-brushing only. If it will be able to controll the composition of deoxidation-product, the covering and the removal-facility of slag may be improved.In this process, it is unable to controll the properties of weld metal by flux as in cases of the submerged arc welding process and manual arc welding process.Authors intended to controll the weld metal and slag obtained by the C. S. Arc Welding Process by means of adjustment of supplied gas. And they researched experimentally on the effects of oxygen mixed in the supplied gas.According to the results of experiments, they recognized the following facts ;(a) In case of using filler wires having high silicon content, with the increasing of oxygen content of the supplied gas the deoxidation-product changes from silica or silicate saturated with SiO2 to unsaturated molten solution, FeO-MnO-SiO2.(b) The addition of a suitable smount of oxygen to the supplied gas gives good effects on the stability of arc deposition, the facility of removal of thin slag and the improvement of appearance of bead.(c) It is also able to controll the mechanical properties of weld steels by the addition.

Aneurysm of the Pulmonary Artery Due to Schistosomiasis

Schistosomiasis exists in Egypt as: (a) Haematobium, mainly urinary and (b) Mansoni, mainly intestinal. The lungs may be affected as follows: 1) Migration and death of the worms in the lungs leading to a verminous pneumonia (uncommon). 2) The deposition of carried living ova in terminal arteriole, Mansoni causing the most mischief. This leads to parenchymatous, bronchiolar and vascular changes. Endarteritis obliterans with angiomatoid formation and the development of the “bilharzial tubercle” are characteristic. 3) Aneurysmal dilatation of the pulmonary artery and its branches is a late manifestation probably due to a local weakening of the arterial coat from schistosoma ova deposit as well as associated malnutrition aided by increased pulmonary circulating blood volume and a gradual rise of blood pressure in the pulmonary circuit. 4) Dyspnoea is a constant feature in cardiopulmonary schistosomiasis, cyanosis signifies right ventricular strain and/or bronchiolar narrowing. The congested veins may conduct right ventricular pulsations. A pulmonary diastolic murmur may be heard. 5) The radiographic appearance shows enlargement of the right ventricle and the pulmonary artery, and its branches, beading and tortuous appearance of the small vessels. Pseudohoneycoming of the lung parenchyma and exaggerated bronchial shadows make the background. 6) The E. C. G. shows right ventricular hypertrophy with strain when failure sets in.