Stainless Steel Films Research Articles

高温水中における18Crステンレス鋼の酸化被膜構造におよぼす冷間加工の影響

Effects of cold working on the structures and chemical compositions of oxide films of 18Cr stainless steel in water at 300°C were investigated.Main results obtained are as follows:After the non-deformed sample had been heated in water at 300°C for 1 hr, oxide films composed of corundum type oxide containing Fe and Cr were formed on the surface of the sample. When the sample deformed 5% or 15% by tension was heated under the same oxidizing condition, oxide films consisting of not only the corundum type but also the spinel type oxides were produced on the surface of the sample and the spinel type oxide in the films increased with increasing tensile strain.The oxide films formed in water at 300°C on the sample which had been deformed 15% by tension and annealed to relieve the stress, were composed of the corundum type oxide only.In the initial stage of the oxidation in high temperature water (150°C), the surface of the sample was covered with oxide films consisting of the corundum type oxide containing Fe and Cr, regardless of whether the sample was deformed by tension or not.

電子顕微鏡によるステンレス鋼不働態皮膜の活性点およびミクロピットの観察

電子顕微鏡によるステンレス鋼不働態皮膜の活性点およびミクロピットの観察

Stainless-steel, nickel and brass protective films produced by cathode sputtering

A standard diode d.c. sputtering system was used for the production of protective films of stainless steel, nickel and brass. Pyrex, low quality steel, sodium chloride crystals and ceramics were used as substrates. The sputtering rate, structure and topography of the films were studied under different sputtering conditions. The composition of the sputtered films was determined by X-ray fluorescence and electron microprobe analysis. Some of these films were also investigated in the temperature range from room temperature to 800°C. An element for the open-ended in-line continuous deposition of protective layers on low quality steel wires was designed. In comparison with the diode d.c. sputtering system, this cylinder-type sputtering apparatus enables 3 to 6 times larger sputtering rates to be achieved.

定電位分極下における不銹鋼のインピーダンスの測定

The present work was conducted to know whether impedance measurement of stainless steel under potentiostatic polarization is possible or not. A semi-conductor type potentiostat and an a.c. bridge were used, and a series equivalent circuit was employed. Converting the obtained data into the parallel equivalent circuit, both parallel capacity and resistance were obtained. The results suggest that the passive film of iron or stainless steel is decreased in thickness or becomes porous before oxygen evolution or transpassive dissolution takes place.

PROCUREMENT AND MAINTENANCE OF GERM-FREE SEINE FOR MICROBIOLOGICAL INVESTIGATIONS.

Germ-free swine were routinely procured by both hysterectomy and hysterotomy (Caesarian section). By means of light-weight portable equipment, piglets could be obtained and transported to the laboratory (without contamination) over distances in excess of 100 miles. The isolators employed in rearing were constructed of stainless steel and flexible plastic film. At weekly intervals, fecal swabs and waste from the floor of the isolator were cultured on blood-agar and in thioglycolate broth, as well as being examined microscopically for the presence of bacteria, yeast, and fungi. The presence of pleuropneumonia-like organisms (PPLO) and viruses in such material was not demonstrable, either by the use of enriched PPLO media or primary porcine-kidney cell cultures. Tissues, body fluids, and cecal contents of piglets sacrificed specifically for microbiological examination were also negative for PPLO, viruses, bacteria, yeast, and fungi. Prenatal infestations by ascarids were not observed. Nutritional problems related to rearing of germ-free piglets, such as hypoglycemia, were not encountered, and the use of an autoclaved commercial sow's milk replacer proved quite satisfactory. The temperature to which piglets were subjected during the first few days of life, however, was very important. The isolator design and application of gnotobiotic techniques to the procurement and rearing of a large germ-free animal such as the pig proved feasible and less difficult than anticipated.

Procurement and Maintenance of Germ-Free Swine for Microbiological Investigations1

Germ-free swine were routinely procured by both hysterectomy and hysterotomy (Caesarian section). By means of light-weight portable equipment, piglets could be obtained and transported to the laboratory (without contamination) over distances in excess of 100 miles. The isolators employed in rearing were constructed of stainless steel and flexible plastic film. At weekly intervals, fecal swabs and waste from the floor of the isolator were cultured on blood-agar and in thioglycolate broth, as well as being examined microscopically for the presence of bacteria, yeast, and fungi. The presence of pleuropneumonia-like organisms (PPLO) and viruses in such material was not demonstrable, either by the use of enriched PPLO media or primary porcine-kidney cell cultures. Tissues, body fluids, and cecal contents of piglets sacrificed specifically for microbiological examination were also negative for PPLO, viruses, bacteria, yeast, and fungi. Prenatal infestations by ascarids were not observed. Nutritional problems related to rearing of germ-free piglets, such as hypoglycemia, were not encountered, and the use of an autoclaved commercial sow's milk replacer proved quite satisfactory. The temperature to which piglets were subjected during the first few days of life, however, was very important. The isolator design and application of gnotobiotic techniques to the procurement and rearing of a large germ-free animal such as the pig proved feasible and less difficult than anticipated.