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Volume 27, Issue 2
Displaying 1-10 of 10 articles from this issue
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[in Japanese]1958 Volume 27 Issue 2 Pages 62-64
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSDownload PDF (1509K) -
1958 Volume 27 Issue 2 Pages 65-70
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSDownload PDF (7680K) -
M. Ozawa, T. Morita, K. Omura1958 Volume 27 Issue 2 Pages 71-75
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSFor the purpose of investigating the influence of oxygen upon the characteristics of consumption of cathode in arc, some experiments have been carried out concerning iron, copper, aluminum, and nickel in oxyargon.
The results are summarized as follows :
1) The apparatus including the flow-meter and mixer of gas, which makes it possible to introduce the small quantity of oxygen (0.1-20%) into argon, has been designed.
2) The consumption-rate of iron has the minimum value in the vicinity of 10% oxygen in argon.
3) The consumption-rate of copper has also the minimum value in the range of 2-10% oxgen in argon.
4) The consumption-rates of nickel and aluminum decrease with the increase of oxygen in argon.
5) The maximum value of consumption-rate of nickel, which corresponds to the minimum value of melting-point at 0.22% of oxygen in argon, could be detected.
(6 According to the standard-diagrams of equilibrium-state of metal-oxygen, the analysis have been made about the characteristics of consumption-rate of cathode in arc.View full abstractDownload PDF (408K) -
M. Ozawa, T. Morita, K. Omura1958 Volume 27 Issue 2 Pages 76-80
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSThough the studies about the consumptions of coated electrodes in welding arc have been made by many researchers, their results are still not enough to analyze the phenomena of consumptions.
It is author's aim to investigate the influences of coating materials upon the melting-characteristics of electrodes in arc.
Some experiments have been performed about the following kinds of coating materials ;
a) H3BO3, Al2O3, BaCO3, CaCO3, and other uni-component coating materials.
b) Illmenite, cellulose, Titanium, low hydrogen, high hematite type, and all of that which include Fe-Mn.
c) Model electrodes.
The results are summarized as follows;
a) The melting-characteristics of cathode are much influenced by the kinds of coating materials, while those of anode are not.
b) The introduction of Fe-Mn into coatings acts to increase the melting-rate of cathode.
c) Generally speaking, a oxydizing agent invites the decrease of melting-rate of cathode and a reducing agent does the increase of it.View full abstractDownload PDF (323K) -
J. Ito1958 Volume 27 Issue 2 Pages 81-85
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSIn the previous report 1 and 2, results of abrasion testing by Quartz sand in a current of water, using shooting type testing apparatus, against fixed specimens. In this report, results of tests using rotating type testing apparatus are described. The metals to be tested are simple stirring fingers, driven around in a pot with quartz sand and water.
From the results of experiments, relation of hardness and abrasion resistance No. of various metals are reported. Resistance No. of Carbon steels and low alloy steels increase almost in proportion to their hardness.
But High Mn steel and High speed steel show good abrasion resistance, however brass does not show good abrasion resistance, for their hardness.
And other abrasion phenomena are also described together.View full abstractDownload PDF (3138K) -
K. Ishihara, M. Iwasa1958 Volume 27 Issue 2 Pages 86-91
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSPowder-cutting method is currently in wide use with success for cutting stainless steel quickly. The use of this method, however, presents some difficulty with cutting and welding operation of 18-8 stainless steel where the heat affected zone within the temperature range of about 500 to 800°C. develops carbide precipitation which is liable to intergranular corrosion. On this account it become essential in manufacturing work to know the extent of influence exerted by heat on the power-cut stainless steel or whether additive heat effect would exist due to subsequent welding operation. Since the powder-cut edge has uneven surface and thick covering of oxide films, it also become necessary to determine to what extent the surface should be treated before welding.
Research from which the results reported here were obtained was undertaken to get information in respect to the effect of heat in powder-cutting and welding on 18-8 stainless steel of 12 mm thickness and effect of surface treatment after cutting on its weldability. The followings summarize the results of the writer's tests and observations.
(1) Heat-affected areas from powder-cutting is relatively very small as compared with that of welding.
(2) When welding is done following the powder-cutting, the heat effect from the powder-cutting was not added to that produced by welding.
(3) In The case of manual arc welding and submerged arc welding, the surface tseatment after powdercutting will have almost negligible effect on mechanical properties of the welded joint. Consequently, light grinding or shotblasting of the surface after hammering slugs is all that is necessary before welding.
(4) In the case of inert gas metal arc welding, the slug at the joint will have considerable influence. In this case, the powder-cut surface should be cleaned with special attention, and preferably with machining.View full abstractDownload PDF (4139K) -
Effects of Welding ConditionsH. Sekiguchi, M. Inagaki, M. Sato1958 Volume 27 Issue 2 Pages 92-98
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSTo make clear the effects of welding conditions on the micro structure and hardness in welding heat-affected zone of high tensile Mn-Si steel, authors have studied cooling phenomena at that zone in the neighbourhood of fusion line.
According to the first report, there was no variation in cooling curves and hardnesses unless the specimens were smaller than 150 mm in width under reported conditions. Therefore, we have continued the investigation on the effect of thickness and welding conditions using certain larger specimens and got some relations between cooling curve of heat-affected zone and the microstructure of the part with maximum hardness.
Each effect of plate thickness, proceeding rate of bead and welding current is significant, but the decrease of bead length does not change the cooling curve seriously, if it exceed sixty or seventy percent of plate length. The electrode type has also a considerable effect on the cooling curve.
Critical cooling curves, which start to allow each appearance of intermediate transformation structure, ferrite and pearlite, have been decided with microscopic investigation (Fig. 9).
And authors proposed that the welding conditions should be selected suitably in the light of above mentioned curves of a given steel, in order to prevent an occurrence of very hardened part in the heat-affected zone by welding.View full abstractDownload PDF (6645K) -
In Case of Single-V-Butt and T-JointH. Sekiguchi, M. Inagaki, M. Sato1958 Volume 27 Issue 2 Pages 99-104
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSAuthors made a series of investigation on structure and hardness of heat-affected zone, welding with single-V-butt and T-joint which are used generally in welding industries.
In this report the softening effect caused by subsequent welding in the neighbourhood of the first pass was examined. On the other hand, an investigation for completely welded specimens was made in case of above mentioned joints.
In single-V-butt joint, the maximum hardness of heat-affected zone was observed in the neighbour-hood of last pass, while in the neighbourhood of root pass softening was caused with the heat effect of subsequently welded passes.
In T type fillet joint, softening was little and the hardness of heat-affected zone was lowered slightly, when the microstructure consisted of martensite mostly. The relation between cooling curves and microstructure in the heat-affected zone of T-joint agreed with that of the second report on high tensile Mn-Si steel (Fig. 9). With reference to hardness, however, lower values were comfirmed in this report, and this fact is considered to be attributable to the use of coated electrode of low hydrogen type.
Among all the welded joints investigated, the heat-affected zone of single fillet T-joint showed the highest hardness on account of rapid cooling, and the heat-affected zone of single bead, manually arc welded, shown next higher value. The hardness of that of single bead submerged arc welded, or single-V-butt joint manually arc welded was lower.View full abstractDownload PDF (4482K) -
S. Morita, S. Goda, M. Ishikawa, J. Imamura1958 Volume 27 Issue 2 Pages 105-108
Published: January 25, 1958
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSIn the production of high tensile weldable steels having the tensile strength over 60 kg/mm2, the allowable ranges of the compositions are quite narrow or the no small scale of heat-treatment equipments are required for quenching and tempering after rolling. In order to avoid these troubles, the authors tried the cooling of materials within the range of Ar3 to Ar1 and from the temperature slightly above Ar1 down to the room temperature. According to the results obtained by this experiment, the strength increases exponentially and the elongation decreases, with the increase of cooling rate. Impact value is restored within the range of the moderate cooling rate at Ar3-Ar1, but decreases continuously with decreasing the rate from the temperature slightly above Ar1.
Consequently, the accelerated cooling at Ar3-Ar1 instead of air cooling during the normalizing operation is effective owing to the recovery of impact value.View full abstractDownload PDF (3201K) -
S. Morita, T. Ito, T. Yonei, M. Fujimoto1958 Volume 27 Issue 2 Pages 109-113
Published: January 25, 1958
Released on J-STAGE: December 10, 2009
JOURNAL FREE ACCESSThis paper reports the effect of post-heating on the bending test result in manual arc welding of the rail joint when the joint type, the electrode type, and prenehting conditions are properly determined.
The results are summarized as follows:-
1. A satisfactory joint can be obtained when low hydrogen electrodes (E 7016, E 8016) are applied to shovel shape joints, preheating bases and webs of rails at 400°C, and head at 200°C. And applying the post-heating at 600°C for 30min. directly after welding has an appreciable effect on improving joint ductility.
2. Statistically no significant difference could be observed between the breaking load of as welded and of post-heated weld joints in head up bending test with 1 m. span length, but the bending deflection and the fracture energy obviously show the excellence of the post-heated weld joint. Therefore, it is proper to adopt the bending deflection or the fracture energy as a criterion of the bending test in addition to the breaking load.
3. As a result of this experiment, the authors propose to adopt the fracture energy over 3000 kg-m or the deflection over 45mm in addition to the breaking load over 90 tons as the tentative standard of manual arc weld joint of 50 kg/m P. S. rail.
4. C% and Ceq% of the rail materials seem to have a considerable effect on the bend ductility of the weld joints.View full abstractDownload PDF (3603K)
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