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Volume 33, Issue 4
Displaying 1-8 of 8 articles from this issue
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Hochiyo Sakaki1964 Volume 33 Issue 4 Pages 335-342
Published: April 25, 1964
Released on J-STAGE: August 05, 2011
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Shin'ichi Kaku1964 Volume 33 Issue 4 Pages 343-348
Published: April 25, 1964
Released on J-STAGE: August 05, 2011
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Discussion of Some Factors Affecting the Weld PerformanceTsuneo Toyooka1964 Volume 33 Issue 4 Pages 349-356
Published: April 25, 1964
Released on J-STAGE: August 05, 2011
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Uichi Hashimoto, Hiroshi Kihara, Yoshio Ando1964 Volume 33 Issue 4 Pages 357-363
Published: April 25, 1964
Released on J-STAGE: August 05, 2011
JOURNAL FREE ACCESSThe first nuclear power station in Japan (Advanced Calder Hall type, 166 MW electric) is now under construction at Tokaimura.
Construction of several new nuclear power stations will begin within a few years and also building project of the first nuclear powered ship (6500 G.T.) has been started in 1963.
Al-killed steel plates 8094 mm thick were manually welded for Tokai reactor pressure vessel and its steam raising units were constructed with 5474 mm thick boiler plates using both submerged arc and manual welding. JPDR is a small BWR (12.5 MW electric), and the inner surface of its pressure vessel was stainless steel cladded by submerged arc process.
Researches on the welding of the nuclear reactor have been extensively carried out by Japan Welding Engineering Society and also each industrial plant is doing its own researches. The study on the effect of irradiation on the properties of materials has been just started.View full abstractDownload PDF (5622K) -
Properties of Weld Metal for Ferrite Stainless Steel (18% Cr steel)Toshikage Ikkai, Fuminori Watanabe1964 Volume 33 Issue 4 Pages 364-373
Published: April 25, 1964
Released on J-STAGE: August 05, 2011
JOURNAL FREE ACCESSHigh Chromium steels have been used for chemical plants as heat-and corrosion resistance steel. As one of ferrite stainless steele of this kind' we can mention an 18 % Cr steel used at the temperature of 550°C to 700°C.
This steel has such drawbacks as the cold notch shortness, coarse crystal grain, blittleness at 475°C, sigma phase formation etc., and cannot easily be welded. Almost this most of these steels have been, therefore, manually welded.
In order to achieve the automatic welding, we have recently made on trial the bonded fluxes which are added with specific alloy components, investigated various weldability and jointing prope, rties of the submerged arc weld metal by means of the above fluxes, and also examined several brittleness phenomena, which seemed to be problematic in the use of welded apparatus.
The test results can be summarized as follows.
(1) As for the bonded flux, H 430 for 18 Cr steel, DC reverse polarity should be used in welding.As this flux is characterized by low hydrogen, the removal of slag is somewhat difficult.
(2) Crystal grains of the submerged arc welded metal could be microrefined according to JIS 6-7 by virtue of Al, Ti and Cb effects.
(3) The most important problematic point in welding the 18 Cr steel is that the transition temperature is high, and the impact value at room temperature is low. When all the deposit metal was tempered at 750 °C, its impact value at 15 °C was very good, i.e., approximately 8kg·m/cm2.
(4) The weld metal shall be preheated at 200 °C to 250 °C to abate the stress caused by rapid heating and quenching in time of welding, and prevent the crack. Air Cooling at 750 °C 2h is desirable for the heat treatment after welding.
(5) The 475 °C brittleness of the deposit metal becomes remarkable, when age-treatment is carried out for 1800h. At 300 °C, the impact value reduces to 3 kg-m/cm2.View full abstractDownload PDF (4396K) -
Toyoo Maeda, Toshio Yada1964 Volume 33 Issue 4 Pages 374-382
Published: April 25, 1964
Released on J-STAGE: August 05, 2011
JOURNAL FREE ACCESSIn the previous report, a method was proposed to exactly analyse shrinkage distortion due to spot heating on a rectangular plate. However, it was necessary to solve a set of infinite simultaneous equations for every aspect ratio of the plate and for every location of heated point. As this is rather inconvenient to perform, the authors sought for some methods for approximate analyses.
Analytical expression for the displacement due to a shrinkage source in an infinitely long straight zone should give good approximation when the aspect ratio of a rectangular plate exceeds a certain value. It was shown that the effect of the length diminishes quite rapidly. This leads to the conclusion that the shrinkages chiefly depend on the breadth of the plate, while the length has little effect on them.
It may be reasoned that the effect of the edges further away from heated point can be neglected if the heat is applied on a point in the vicinity of an edge or a corner of the plate. Then the principle of reflection may be taken to simplify the problem. In fact, the formulae have been substantially simplified.
The results obtained through the above analyses would contribute to the derivation of simple approximate formulae.View full abstractDownload PDF (435K) -
Toyoo Maeda, Toshio Yada1964 Volume 33 Issue 4 Pages 383-392
Published: April 25, 1964
Released on J-STAGE: August 05, 2011
JOURNAL FREE ACCESSIn the previous reports, an analytical method was proposed to study shrinkage distortion due to spot heating on a rectangular plate. First, a method for exact analysis was presented. Then several methods of approximate anlyses were sought for.
In this report, approximate formulae were deduced by combining the results from the rigorous and the approximate analyses with those of numerical calculations. These formulae are simple and self-explanatory, therefore very convenient to apply in practice. They also lead to a clear understanding of characteristic features of shrinkage distortion in rectagular plates.
For example, the formulae indicate that the shrinkages chiefly depend on the breadth of the plate, while they are little affected by the length. It is also shown that if heat is applied on a point far away from the plate edges, the length of the plate reduces approximately by 27πδ/2bE, where-δ, 2 b and E designate the magnitude of shrinkage source, the breadth and Young's modulus of the plate, respectively. The quantity 2δ/2bE is the fundamental value which appears in all the exact or approximate expressions.
Calculated values from the approximate formulae satisfactorily agreed with experimental ones.
The results obtained through the present investigation are expected to provide a basis for the analysis of shrinkages in any locally heated plates.View full abstractDownload PDF (1888K) -
Kohei Ando, Shunji Nakata1964 Volume 33 Issue 4 Pages 393-398
Published: April 25, 1964
Released on J-STAGE: August 05, 2011
JOURNAL FREE ACCESSThe variation of air pressures P1, P2 of the parts (1), (2) of the cylinder of a spot welder operated through compressed air, as well as the velocity ν and displacement z1 of the piston are calculated under the assumption that the pressure of the air source is maintained constant at the value PH at the inlet (1), Fig. 1.
The results are shown in Figs. 2-5 and in Table 1, in which Fig. 2 is the case when the effect of moving mass M is assumed to be zero and Fig. 6 is the case when the gravity effect is taken into consideration.
With the time constant Ta2 as defined in equ. (1), variations of P1, P2, v and z1 are related to time t in dimensionless forms as shown in the figures, the parameters being the dimensionless acceleration (equ. (9)), and the ratio of the effective sectional areas S1. S2 of air circuits (1), (2). The boundary conditions are shown in the figures, V10 being the initial volume of (1) and V0 the sum of volume of (1) and (2) : V0=V1+V2=V10+ V20.
When the piston moves at the velocity ν0 as defined in equ. 5, the pressure P2 does not vary, and the air in (2) is discharged through S2 at sound velocity (See equ. (7)). This velocity is taken as the denominator of the dimensionless velocity.
It is interesting to note that the accelerating force, which is proportional to (P1-P2) or (γ1-γ2) in dimensionless expression, decreases when J (or M) is decreased, and the time tm required for the piston to reach the bottom (i.e. V1=V0, z1=z0) varies only in small range even when j (or M) is changed in wider range.
Calculation was made by the step-by-step method, i.e. dγ1, dγ2, dν/ν0, dz1/z0 corresponding to dt/ Ta2 were calculated from equ. (11), (12) and (18).
It is assumed that equation (6) holds true for the whole range of P2.View full abstractDownload PDF (411K)
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