This paper describes a new nondestructive approach to measuring the brittle transition temperature of several steels by means of hardness testing. The transition temperature in hardness tests is defined as the intersections of the two straight-lines in the plot of the logarithmic Vickers hardness vs. the reciprocal of absolute temperature. The transition temperature of hardness were discussed in comparison with the results of the usual tensile test and a specially instrumented Charpy impact test. It was concluded that the first and second transition temperatures of hardness were equivalent to the ductile transition temperature and brittle transition temperature respectively. The approach has been applied effectively as surveillance measures of (1) distributions of brittle transition temperatures of pre-strained welded steel plates, and (2) increases of the nil ductility transition temperature due to neutron irradiation for nuclear reactor vessel steels.

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Steady-state creep of simply supported circular cylindrical shells with open ends under internal pressure is analysed numerically by the extended Newton method combined with the method of finite-difference. Creep theory of Mises type and power creep law are assumed. Numerical calculation is carried out for long and short shells with creep exponents n=1 through 5. the effect of shell geometry and that o f non-linearity of creep law are elucidated in detail. The numerical results are compared with those of a semi-infinite sandwich shell. The present method of analysis was found to be quite stable, and accurate results were obtained by a few times of iteration.

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The thermo-elastic solutions for the case of one heat source near a circular hole in an infinite elastic plate are given in the steady-state condition using the thermal expansion displacement for "zero stresses". It is assumed that the temperature along the edge of this hole is held at zero degree always. Numerical calculations are done for the temperature distributions near the hold and the stresses along x and y axes.

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The fatigue strength of the press-fiteed shafts is affected by the configuration near the end of fit. In this study, the above problems were investigated from a view point of stress concentration by using the two dimensional photoelasticity. The configuration near the end of fit was decided as follows. The configuration of the hub was kept constant while shafts were varied as plain and filleted. Furthermore, the relative position between the end of fit and shoulder was varied. Then, it was studied what relations were there among the configuration near the end of fit, the concentration of the bending stresses and the fit pressure, based upon more systematic experiments. The obtained results indicated a good agreement with the results of the bending fatigue tests, and the effects of the overhang quantities and the configuration of the fillet on the stress concentration were clarified.

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Endurance limits and their reliability of larger casting and forgings are statistically discussed on the rotating beam fatigue test results using laboratory-sized specimens obtained from two B&W 98 type crank throws (pin diameter: 868mm, weight: 20 ton, tensile strength: 56 kg/mm²) of which the one is die forged steel and the other is ordinary cast steel. 1) Fatigue life variance of the casting, which is explained in coefficient of variation (standard deviation of fatigue life/mean fatigue life) is about 10% larger than that of the forging. 2) Mean values of endurance limit and standard deviation of the casting, which is determined with staircase method are respectively 22.1 kg/mm² and 2.87 kg/mm², while those of the forging are 28.3 kg/mm² and 1.17 kg/mm²/ Therefore, it should be noted that confidence limit of endurance limit (mean value-standard deviation ×2) of the casting is 16.4 kg/mm², while that of the forging is 26.0 kg/mm²; also(mean value-standard deviation ×3) of the casting is 13.5 kg/mm², and that of the forging is 24.8 kg/mm².

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In a rotor consisting of a drum which rotates around the horizontal axis and represents a rotating ill-balanced mass in itself, an unbalanced mass adhered to the drum's wall under the high speed rotating condition causes large vibration. As counter-measure for this, it is most effective to control the mass so as to be distributed nearly uniformly in the drum during its high speed rotation. for this purpose, we have developed an ABC device which makes use of the distribution of an ill-balanced mass system that can change of itself when the centrifugal force in the drum is smaller than the gravity, and have analyzed the effect of the device statistically. The effectiveness of the device can be stated as P=1-(1-δ)^N The experimental results have been found to agree well with this expression. Furthermore, the ABC device is described in details; it consists of a velocity type detector composed of a spring plate, a mass, and a mercury switch so that it is an amplifier type detector with the use of resonance, and of two time limit circuits. discussion is made from the vibration theoretical view point.

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Treated in this paper is the laminar swirling flow in the hydrodynamic entrance region of a circular pipe, in which the entering flow has uniform axial-and linearly varying tangential-velocity components. The analysis is carried out within the framework of the boundary layer theory, the solutions being obtained by means of an extended form of the finite difference method invented by Leigh and Terril. the following results are obtained from the analysis: (1) The entrance length is significantly increased by the presence of swirl at the entrance section. (2) The additional pressure drop based on the center-line pressure at the entrance section is considerably decreased as the swirl is increased. (3) If the wall temperature is constant, the local Nusselt number is increased by a few percent at a certain distance downstream from the entrance section when Prandtl number is taken as 0.72. (4) The damping coefficients of the swirl show an exponential decay shortly after the entrance section. However, in the immediate neighbourhood of the entrance section, the damping of the swirl is a little faster than the exponential decay.

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Flow inside a diffuser consisting of two curved walls of logarithmic spiral and two parallel flat walls was investigated. Secondary flows and boundary layer growth were measured in detail. A method of calculation for boundary layers and diffuser performance was given. (1) A pair of secondary flow vortices due to flow curvature is recognized. They are intense on the convex wall and very weak on the concave wall. (2) Secondary flows build up typical skewed boundary layers on the side walls. Their velocity profiles are approximately expressed by the formerly known formula for skewed boundary layers of non-decelerating flows. (3) On the side flat wall the boundary layer growth is little, while it is very rapid on the convex wall. It is related with secondary flow conditions. (4) With consideration of these flow phenomena, a method of numerical calculation was given using orthogonal curvilinear coordinates. Effects of inlet boundary layer thickness and Reynolds number were also studied.

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This paper deals with the jet flames of rich propane-air mixtures in a counter air stream. At a constant jet nozzle pressure a stable combustion can be obtained within the appropriate ranges of the air-fuel ratio of the jets and the velocity of the counter air streams. In order to examine the fundamental characteristics of the flames, the behaviour of some typical flames within the stability curve is studied by means of visual observation and temperature and concentration measurements. A concept of similar flame based on the temperature profile at the maximum temperature section is introduced and confirmed experimentally. By using this concept a dimensionless flame stability curve can be obtained. The temperature, concentration and heat release rate profiles give a good explanation of the estimated relationship between the flame and flow pattern.

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If a shell or flue is welded to a tube plate by T(tee) joint, remarkable thermal stress will occur at the welded parts owing to the temperature difference between shell and flue. Therefore, welded parts shall be inspected by radiographic examination precisely, but it is not so easy to carry out this examination because of complexity of such a boiler. In order to establish an acceptable method of radiographic examination, author made the test plates by the same welding procedure as applied for actual boilers, and examined the welded parts radiographically at various conditions. Authors has also studied on the relationship between film exposure and thickness of welded part to keep sufficient penetrant performance through the whole length of welded length of welded T joint.

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This investigation has been carried out in order to examine physical properties, mechanical properties, frictional properties and machinability of sintered copper-glass compacts. And it has been also examined if glass added in copper based compacts is useful as a lubricant to prevent a seizure. Specimens are made by being compacted at 4 ton/cm² for 2 min and being sintered at 850°C for 60 min in a vacuum of about 10^-2mmHg. The results are as follows: The bending strength and the tensile strength of the copper-glass compact decrease with the increase of the glass content. The hardness increases up to 20% glass contents, but it becomes small again at 30%. and the amount of wear slightly increases and the seizure load decreases. Smaller amount of wear and larger seizure load are obtained by adding 10% glass contents to a copper-2 graphite compact. Furthermore glass in the compact melts, flows and covers all the surface of the compact. 1% glass in the copper compact makes the turned surface smoother as well, and the chips receive severe deformation.

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