JOURNAL OF THE JAPAN WELDING SOCIETY
Online ISSN : 1883-7204
Print ISSN : 0021-4787
ISSN-L : 0021-4787
Volume 24 , Issue 5-6
Showing 1-8 articles out of 8 articles from the selected issue
• S. Ito, K. Honda
1955 Volume 24 Issue 5-6 Pages 183-188
Published: 1955
Released: December 10, 2009
JOURNALS FREE ACCESS
An useful formula of the temperature distribution during flash and butt welding has been established and the relationship between welding variables have become clear and the optimum welding conditions can be obtained easily.
If the heat flow is linear, the material is infinite and the clamp displacement velocity is constant, the following relationships have been acquired by using the theory of thermal conductivity.
For the initial current
θ=qt1/2/chp√π{e-w2-√πw(1-erf w)}
For the constant velocity flash welding
θ=4q/cpv√π{e-vX/4h2∅(√vl/8h2, vX/8h2)}
where q is the heat generation, t is the welding time, h is the heat diffusibility, c is the specific heat, x p is the density, w=x/2ht1/2, X is the distance from the instantaneous flashing surface, x is the distance from the initial contact surface, erf w=2/√π∫ω0 e-ξ2dξ, l is the burn-off distance, v is the clamp displacement velocity.
By comparing these formula with the experimental data, the following conclusions have been obtained.
1) The effective heat generation is proportional to the clamp displacement velocity.
2) Influence of the heat radiation and cooling effect at clamps cannot be neglected
3) There is an upper limit in the temperature distribution and this maximum temperature distribution can be represented by
4) Regarding the flashing surface temperature as a standard, the temperature distribution curves can be obtained according to various clamp displacement velocities and burn-off distances only by calculations without any assumptions.
• H. Suzuki
1955 Volume 24 Issue 5-6 Pages 188-195
Published: 1955
Released: June 12, 2009
JOURNALS FREE ACCESS
A mathematical analysis of the flashing operation as well as the nature of the stabilized temperature distribution during flashing, has led to an introduction of a new set of parameters with which any temperature distribution with any material will be satisfactorily correlated into a single, standard distribution form. The correlation of experimental data so far obtained with aluminum alloys, steels and molybdenum, seems to be quite satisfactory.
A method of predicting the amount of critical burn-off which is necessary to establish the stabilized temperature distribution has bnen proposed, as well as a new procedure for predetermination of satisfactory flashing conditions for any material.
The effect of the flashing variables, such as the material constants, specimen size, flashing velocity or acceleration of flashing, and the initial clamping distance, on the stabilized temperature distribution has been discussed.
With the help of the present theoretical analysis of flashing operation, a better understanding of the flashing operation and the nature of the temperature distribution during flashing may be obtained.
The full report has been published in English March 1954 by Transportation Technical Research Institute.
• H. Kihara, T. Kusuda, K. Iida, I. Nakamura
1955 Volume 24 Issue 5-6 Pages 195-207
Published: 1955
Released: June 12, 2009
JOURNALS FREE ACCESS
Some experiments were made to determine the effects of peeping on the residual stress relieving and the properties of the peened weld metal for the low-temperature brittleness in the butt weld joints, , which were prepared from two plates of 1200×500×19mm. by manual welds. Details of the specimens and the conditions of welding and peening are shown in Fig. 1, 2 and Table 1-5, respectively.
The residual stresses as welded and after peened were mesured by three methods successibly, for the purpose of increasing the reliability of the measured data.
Electric resistance strain gauges were fastened on the plates, as shown in Fig. 4, which then was drilled as follows:
1. One Hole Relaxation
2. Two Hole Relaxation
3. Plug Relaxation
4. Slit Relaxation
Austrian tests were conducted as the extensive experiments to research the effects of peening on the low temperature brittleness of the weld metal.
Measured residual stresses are shown in Fig. 5-8, and the results of Austrian Tests conducted at the range of -650°C... -70°C are shown in Table 6, respectively.
Summary results of measured longitudinal residual stresses are shown in Table 7.
Fig. 8 represents the summary of longitudinal mean stress resulted from the various peeping conditions. Except for the specimen No. 2, in Fig. 8, longitudinal stresses were considerably reduced by peeping compared with the as-welded specimen, namely in the specimen No. 3, peening lowered the longitudinal stress of 28 kg/mm2 tension.
The following conclusions appear to be warranted:
1. The first laver shall not be peened.
2. Peening of the last layer should be considered a dangerous practice which greatly increases the hazard of low temperature brittleness.
3. Hot peening confers the undesirable effects on the properties of weld metal.
4. The welds shall not be over peened.
5. As the stress relieving procedur, peening only the last layer by 2-in. stroke is even effective.
6. Transverse stresses were lowerd to some extent by peening.
• M. Otani
1955 Volume 24 Issue 5-6 Pages 207-211
Published: 1955
Released: June 12, 2009
JOURNALS FREE ACCESS
• N. Nagai, H. Suemitsu, T. Owa
1955 Volume 24 Issue 5-6 Pages 211-215
Published: 1955
Released: December 10, 2009
JOURNALS FREE ACCESS
The effects of the width of the "Synthetic Impact Test" specimen are investigated. Width of the specimen are changed from 0.4cm to 1.0cm. By these tests the brittle parts of the Heat-affected zone can be recognized from the appearences of the fractures. As the results of these experiments followings are known:
1) The impact value changes approximately linearly with the width of the specimen when the notch shape is not so severe.
2) In this impact test the side of parent plate creavage first, so that the brittle range of the Heataffected zone can be recognized.
• [in Japanese]
1955 Volume 24 Issue 5-6 Pages 216-219
Published: 1955
Released: June 12, 2009
JOURNALS FREE ACCESS