It is the aim of this paper to report on experimental study on highly effective method of annealing stainless steel plate to give it proper tension as spring material. Hereunder are summarized the results of our study. (1) The stainless steel plate is to be annealed in the following method. Its tension is to be first reduced to 30% by cold rolling, and then the plate is to be annealed at 400-650°C of temperature in non-oxidative atmosphere, under tension not exceeding 20% of tensile strength. (2) The springs made of stainless steel processed in the above mentioned method have about twice as much strength in fatigue strength and spring limit as copper alloyed springs, and the steel thus annealed, being productive of high resilient mechanism, is fit for production of all varieties of springs. (3) The passivation of stainless steel treated in the above mentioned procedure is to be made in solution of 30% HNO 3+1% HF at about 30°C temperature.
An apparatus for tensile testing of metallic materials under constant high hydrostatic pressure up to 15000kg/cmcm2 has been designed and constructed. This apparatus is so devised that during the tensile test two plungers each of diameter of 30mm are fixed in a high pressure cylinder, held fast together so as to keep the pressure inside the cylinder constant, and that the specimen which is attached to the lower plunger will be pulled by the shift of position of the cylinder to these plungers. The fluctuation in pressure during the test is so small that it is not detectable by the ordinary manganin pressure gauge. The change of the pressure is workable during the test, in case it is desirable by using a couple of Bridgman type tensile yokes and making the lower plunger, which is released of the specimen, shift its position by itself. In this case the fluctuation in pressure increases, but it remains within 100kg/cmcm2. The load is measured by a magnetostrictive load cell set in the high pressure chamber, The ongation of the specimen is obtained by measuring the movement of the cylinder. The dimension of the specimen is 3-5mm in diameter and 30-40mm in gauge length. The maximum load applicable to the specimen is 1000kg.
Two kinds of low alloy steel of about 100kg/mmmm2 in tensile strength were put to tests: their specimens, notched and unnotched respectively as well as fatigue cracked, to the fatigue test of low pulsation cycle of tensile, and their fatigue cracked specimens in the range of 16 to 60mm in diameter to the static tensile test. The results of the tests are given as follows. (1) The fatigue strength of the unnotched specimens scarcely drops lower than their tensile strength till the pulsation of 104 cycles is reached, whereas of the specimens, both notched and cracked, the static strength, though higher than their tensile strength, decreases linearly with increasing number of pulsation cycles. (2) Fatigue strength of notched specimens after inititating crack on notch root coincides with that of fatigue cracked specimen. (3) Critical stress intensity factor KIC is constant independently of apecimen size and crack depth, when the external diameter of specimens is above 25mm. (4) Thefi nal fracture of low cycle fatigue occurs in the fatigue cracked specimens, within the diameter range of constant KIC, when their stress intensity factor KI reaches KIC. But when the diameter of are below this range the fracture condition of the low cycle fatigue does not coincide mechanically with that of Fracture Mechanics.
In a series of studies on the strength of inhomogeneous metallic materials, the authors have conducted an investigation on the macroscopic and X-ray elastic modulus of cast iron, and reported the experimental results in the previous papers. It has been suggested that the shape of graphite has little influence on the value of X-ray elastic modulus, but that the value of macroscopic elastic modulus is remarkably varied with the change in its shape. It is very interesting and significant to predict, from the known elastic moduli of component materials, the macroscopic and X-ray elastic modulus of inhomogeneous metallic materials, such as cast iron, powder metallurgy products and two phases alloys. In this paper report is made of the analytical treatment concerning the elastic modulus for inhomogeneous metallic materials which was carried out, using the simple mechanical models, and the calculated results are presented with reference to the experimental results obtained with cast iron. It is assumed that aninhomogeneous metallic material is composed of the cube-shaped unit structures, and that the unit structure contains a particle of B-phase floated in the matrix of A-phase. This unit structure is divided into two columns, one of which is composed of only A-phase and the other is composed of A- and B-phase. The condition of constant stress or constant strain is supposed as combining these two columns. Furthermore, the latter column is sub-divided into two parts, one of which consists of A-phase and the other B-phase, and the condition of constant stress or constant strain is also assumed as bond between these two parts. The analytical calculation of cast iron has been made assuming that the graphite particle is cube-shaped in spheroidal graphite cast iron, and plate-shaped in flake graphite cast iron, and that the value of elastic modulus is zero for the graphite particle. Good correlation is obtained between the analytical and the experimental results of these two sorts of cast iron. This analytical treatment is considered to be applicable also to powder metallurgy products, two phases alloys such as (α+β) brass, and so on.
It has been shown by Warren and Averbach that the coherently diffracting domain size and the micro strain contributions to the broadening of the line profile can be separated by application of Fourier series method. However, this method requires at least two orders of the same reflection which are not necessarily obtained in many cases. Garrod and Auld, Krishnan et al. have suggested, and carried out, to separate the domain size and the micro strain by application of the approximation method which can be analysed from a single reflection only. In the present study, the value of the domain size and the micro strain obtained from a single reflection only were compared with those obtained by the Warren and Averbach method, by using (111), (222), (200) and (400) reflections of electrodeposited nickel. Moreover, the results obtained by Fourier series method were compared with those obtained by the half-value breadth method. The results obtained are summarized as follows. (1) The domain size on (111), (20) reflections, determined from the intercept of -lnAL/L vs. L where <D>e>>L, agree with those obtained by Warren and Averbach method within the experimental errors, but it is found not to be possible to determine the domain size on (222), (400) reflections. (2) It is found to be possible to determine the domain size on the first and the second order reflection from-(dALdL)L→0=1/<D>e, where L→0, ADL, l0≅1 and the results approximate comparatively to those obtained by Warren and Averbach method within the experimental errors. (3) It is found that the mean value of the r.m.s. strain calculated by equations and approximate comparatively to those obtained by Warren and Averbach method except for the large L values of (111), (200) reflections. (4) Comparing the domain size and the micro strain obtained by the half-value breadth method and Warren and Averbach method, the half-value breadth method gives the larger value for the domain size and also shows a little larger value for the micro strain, when the r.m.s. strain obtained by Warren and Averbach method are considered over the average domain size.
It is recognized that electrodeposits are similar in microstructure to the microcrystals produced by cold work and the crystals with high internal stress and preferred orientation. In order to obtain the knowledge of microstructures in chromium, electrodeposited from a chromic acid plating bath as a function of bath temperature, the X-ray diffraction line profiles of its deposits were analysed by Fourier series method which was practicable by using a single reflection only. The information on micro strain, coherently diffracting domain size was obtained from the Fourier cosine coefficients. Moreover, the effect of unresolved Kα line profile and Kα1 line profile separated by Rachinger's graphical method on the r.m.s. strain and the domain size were examined. From the experimental results, the following conclusions have been derived. (1) The value of r.m.s. strain obtained by using unresolved Kα line profile is a little larger than that in the case of Kα1 diffraction line profile separated by Rachinger's graphical method, but the domain she is slightly small in the case where unresolved Kα line profile was used. (2) It is found that the r.m.s. strains in electrodeposited chromium analysed on the (211) diffraction line profiles have decreased with increasing bath temperatures, in the range of 40 to 70°C, and again increased at 75°C. The influence of bath temperature on the stored energy and the dislocation density derived from the mean squared strain show a similar tendency as the r.m.s. strain. The coherently diffracting domain size in electrodeposited chromium on the (211) diffraction line profile has increased with increasing bath temperature, in the range of 40 to 70°C, and again decreased at 75°C. (3) The reflecting plane dependence of the r.m.s. strain and the domain size in electrodeposited chromium obtained from bath temperature of 60°C have been investigated on the three planes of (110), (200) and (211). It is found that the r.m.s. strain has increased in the order (200), (211), (110) and the domain siza in (211) plane is smaller than that in the case of (110) and (200) planes, but between the domain size in (110) and (200) planes, no marked difference has been recognized.
Density of glasses in the systems As-Se, As-Se-S, As-Se-Te and As-Se-Tl were measured as functions of composition and annealing. Some thermal expansion measurements were also conducted. The results obtained are summarized as follows: (1) The density of the As-Se glass increases with increasing concentration of As up to its maximum at about 42 atomic per cent As, and then decreases (Fig. 1). (2) The effect of the third component X (X=S, Te and Tl) added to the As2Se3 glass on the density change is seen in Fig. 2. (3) Contraction-expansion curves at constant temperatures of the As-Se glass are shown in Figs. 3-6 for temperatures ranging from 108° to 165°C. Implication of the results as to the constitution of the chalcogenide glasses was discussed based on the molar volume conception.
The influences of solvents and electrolytes on the yield, electrical conductivity, strength and eccentricity in the cataphoretic deposition of alumina were investigated. The cataphoretic suspension was composed of alumina powder, electrolytes, alcohol and water. The deposition was made by applying ground potential on the coating electrode and positive potential on the opposite electrode. The results are summarized as follows: (1) Hamaker's formula on cataphoretic deposition holds good even in the case in which electrolytes are added to the cataphoretic suspension. (2) Addition of water to the cataphoretic suspension containing alcohol as solvent increased the cataphoretic yield and electrical conductivity. The suspension containing 50%/50% alcohol-water gave good yield and presented smooth deposition surface. (3) The addition of nitrates saw better cataphoretic deposition than the addition of sulfate and acetate. Especially, the addition of aluminium nitrate (Basic) in combination with magnesium nitrate saw most stable and effective deposition. (4) Aluminium nitrate (Basic) increased hardness of alumina deposition after sintering, and decreased its ductility, while magnesium nitrate, on the contrary, decreased its hardness and increased its ductility. Their combination is therefore recommended. (5) The eccentricity of alumina deposition on coil decreased as the electrical conductivity of suspension increased.
The films of BaTiO3 were prepared by two types of evaporating methods. The films made by these methods were baked in air at various temperatures for different length of time. Their composition was checked by means of X-ray diffractometer. In the case of the films which were not at all baked, no BaTiO3 was seen at all. When these films were baked gradually from a low temperature to higher temperatures, turned into tetragonal phases at 1200°C. The above phasic changes took place regardless of difference in substrate temperatures used (250°C-500°C), and were not affected by either of the evaporating methods applied. The crystal formation of BaTiO3 was closely related to the evaporation rate, and was little influenced by the temperatures of the tungsten heater.