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Volume 24, Issue 2-3
Displaying 1-11 of 11 articles from this issue
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S. Ito, K. Honda1955 Volume 24 Issue 2-3 Pages 67-71
Published: 1955
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSFoundamental formulas were derived by the following assumptions.
1. The material and electrode are thermally one body and infinite.
2. The current flows uniformly over the path.
3. The specific heat, density and diffusibility of heat of materials and the mechanical equivalent of heat are constant.
4. The temperature coefficient of the specific resistance and current density are functions of time.
5. The contact resistance distributes uniformly on the surface and keeps constant until it disappears.
6. A thermally neutral.point exists on the center line of the current path because of the cooling effect of the electrode.
Then, from these foundamental formulas, temperature distributions at various stages of spot welding are derived.
At last, the effect of the thermal isolation by the plate surface and the plate end is calculated.View full abstractDownload PDF (296K) -
Effects of Various Welding OperationsH. Sekiguchi, I. Morimoto, T. Maki1955 Volume 24 Issue 2-3 Pages 72-80
Published: 1955
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSIn this research, effects of welding operations on usability of gas welding rod and mechanical properties of gas weld steels were investigated by using the welding rod III containing 1, 37 % Mn and 0.13% Si.
The results obtained are as follows:
1. The mechanical properties of weld steels, which were deposited with layers not exceeding about 5mm in thickness, were excellent.
2. The continuous welding method should hot be adopted.
3. The weld steels deposited with backhand and weaving techniques had very good mechanical properties.View full abstractDownload PDF (13250K) -
M. Okada1955 Volume 24 Issue 2-3 Pages 80-84
Published: 1955
Released on J-STAGE: December 10, 2009
JOURNAL FREE ACCESSIn respect to welding of penstocks, there should be confirmed the conditions of crack free fabrication. Among them, choice of materials is primary importance. Proper preheating and post treatment of welded part are expected to get favorable effect to prevent crack initiation and its propagation.
Rimmed Steel has a higher transition temperature and top part of a rimmed ingot usually shows a considerable seggregation. Under welding process, the top part is apt to bring about some cracks, especially, sulphur cracks sometimes occur in submerged arc welding.
Therefore it has been decided in this specification that steel plates used for should be better than a certain grade as shown in table.
Plate thickness t mm. Kinds of steel
t≤12.7 ship plate(S.M.)
12.7<t≤25.4 ship plate(S.M.W.)
holding composition ratis of Mn/C>2.5
t>25.4 Killed steel plate
Preheating temperature required is above 70°C for the plate thicker than 25.4 mm. post-heating in furnace at temperature 600-650°C shall be applied to the plate of which thickness is more than 25.4 mm. However, if it is impossible to do, local heating such as induction heating may be allowed to use in place of furnace heating with the order's approval.View full abstractDownload PDF (442K) -
M. Watanabe, S. Minehisa, H. Onoe1955 Volume 24 Issue 2-3 Pages 84-89
Published: 1955
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSWe studied the distributions of residual stresses of the seam-welded and circumferentially welded pipes, changing the welding sequence such as shown in Fig. 2. The results of our experiment were shown in Fig. 3-Fig. 6. To compare these results, we adopted the maximum value of the stress, equivalent stress (σeq) defined by the eq. (1) and the triaxiality ratio (Tr) defined by the eq. (3). Fig. 11-Fig. 14 show these values of each specimens.
Generally speaking, the residual stress distributions in the seam-welded pipes are nearly the same as in the butt welded plate, but the stress distributions of the circumferentially welded pipes are not the same as in the butt welded plate. As shown in Fig. 9, effects of bending moment can be considered in the latter cases.View full abstractDownload PDF (433K) -
M. Yoshiki, T. Kanazawa1955 Volume 24 Issue 2-3 Pages 89-94
Published: 1955
Released on J-STAGE: December 10, 2009
JOURNAL FREE ACCESSWe have performed charpy impact tests of specimens with different'notch radius, which were machined .out from three mild steels having 0.22, 0.29, and 0.40% Cu content respectively.
We have obtained the following' facts:
(1) Using the experimental results by Rinebolt & Harris, and Williams to eliminate the effects of C, Mn, and P on the transition temperature, we have found that the transition temperature is lowered, as the Cu content increases (in the range 0.22-0.40%).
(2) The formula formerly proposed by the authors to give the relation between the notch geometry and the transition temperature, or the absorbed energy at low temperature matches fairly well with the present experimental results.
(3) Furthermore we have got a relation between the absorbed energy at 0°C and the transition temperature determined from 2.6 kg-m/cm2 energy level.View full abstractDownload PDF (404K) -
Effects of Base and Deposited MetalsM. Otani1955 Volume 24 Issue 2-3 Pages 94-100
Published: 1955
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSTensile tests were made on welded butt joints with internal defects produced at the root face, left unwelded, of double V grooved joints (Fig. 2). The load was applied perpendicularly to the weld. The sharp transition phenomena reappeard in the presence of such natural defects.
Five charges of structural mild steels, 23 mm thick, and three electrodes with different transition temperatures were used for the test. The dimensions of the root face (G) and reinforcement of weld (δ) were kept constant (G=6 mm, δ=2 mm) and effects of the notch sensitivities of base and deposited metals on the transition temperatures of welded joints were investigated. Of the two transition phenomena, ductility and fracture, only the latter was observable in the temperature range tested. As the result, it was proved that the fracture transition temperature of welded joint (Trs) could be predicted by the equation,
Trs=0.60Trs(B)+0.45Trs(D)-34 (°C),
where Trs(B) and Trs(D) are the 50% shear transition temperatures of base and deposited metals by V-Charpy impact test.View full abstractDownload PDF (3930K) -
Y. Akita, K. Ikeda1955 Volume 24 Issue 2-3 Pages 100-105
Published: 1955
Released on J-STAGE: December 10, 2009
JOURNAL FREE ACCESSA test has been developed to investigate the influence of side opening on brittle crack propagation using H type notched specimens as shown in Fig. 1.
The brittle crack should pass through narrow neck portion between side openings with high rate of propagation Otherwise, the crack cannot progress straight forwards but turns to the one or both side openings.
It is concluded from the results that.
1) There are three modes of brittle crack propagation depending on h, the distance between side opening and center line, i. e. crack line, and temperature.
2) The "hesitating temperature", at which the brittle crack hesitates either to pass straight through neck portion or turn to side opening, is in reverse proportion to log h. By application of this linear relationship to our conception on the mechanism of influeuce of side opening on brittle crack propagation, the well-known relationship between brittle crack speed V and temperature T represented by log V=k/T+K is obtained and crack speed is calculable, then our conception is proved to be reasonably correct.View full abstractDownload PDF (9572K) -
[in Japanese]1955 Volume 24 Issue 2-3 Pages 106-109
Published: 1955
Released on J-STAGE: June 12, 2009
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1955 Volume 24 Issue 2-3 Pages 109-110
Published: 1955
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSDownload PDF (190K) -
[in Japanese]1955 Volume 24 Issue 2-3 Pages 111-112
Published: 1955
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSDownload PDF (3825K) -
[in Japanese], [in Japanese]1955 Volume 24 Issue 2-3 Pages 113-118
Published: 1955
Released on J-STAGE: June 12, 2009
JOURNAL FREE ACCESSDownload PDF (499K)
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