Kabushiki Kaisha Kobe Seiko Sho

Kobe Steel, Ltd.

Doryokuro Kakunenryo Kaihatsu Jigyodan

Kazutoshi Shimogori

Hiroshi Satoh

Toshio Fukuzuka

Koki Ikeda

Masao Toyama

Toshio Fukutsuka

Etsuo Yamamoto

Kazuo Fujiwara

Hidetoshi Nishimoto

Kenji Miki

Hirohiko Sakai

Shingo Nomura

Fumio Kamikubo

Yasushi Torii

Hiroshi Sato

Haruo Tomari

Junji Kawahuku

Shoji Miyake

Takenori Nakayama

Katsuyuki Ohtsuka

Tatsuo Hara

Kikuo Morita

Takuo Hosoda

Kiyoshi Sugie

Hitoshi Miyazaki

Ryukichi Mizuno

Mutsuhiro Miyakawa

Kazuichi Kajiwara

Hidetoshi Shimoto

Keiichi Wada

Fumio Kami Kubo

Junji Kawafuku

Kohjiro Kitahata

Zn-Mg alloy is plated by vapor deposition on the surface of metals. Since Zn and Mg are vapor-deposited as a vapor mixture of an optional ratio on the surface of metals, plated layers of excellent corrosion resistance, peeling resistance of coating film, formability, etc. can be formed. There is disclosed a method of forming uniform vapor mixtures of Zn and Mg, and vapor-depositing them on the surface of metals as the method forming the vapor-deposited layers.

Zn-Mg alloy vapor deposition plated metals of high corrosion resistance,

Provided herein is an Al-Cr alloy vapor deposited product having high corrosion resistance which can be used under a corrosive environment for a long period of time on account of the outstanding corrosion resistance and heat resistance of the Al-Cr alloy vapor deposited layer.

Al-Cr alloy vapor-deposited material

Disclosed herein is a rolled steel having excellent resistance to sulfide stress corrosion cracking. It comprises 0.20-0.40 wt. % C, .ltoreq.0.50 wt. % Si, .ltoreq.1.90 wt. % Mn, .ltoreq.0.06 wt. % Al, 0.0030-0.0090 wt. % N, 0.005-0.10 wt. % Nb, 0.005-0.050 wt. % Ti, and the balance iron and inevitable impurities. The rolled steel contains at least 4.times.10.sup.8 ultrafine carbonitride particles or 0.1 .mu.m or smaller per mm.sup.3 as a result that a bloom or slab having the above components is soaked, subjected at 1200.degree.-950.degree. C. to rough rolling under conditions of a total reduction percentage of 75% or lower, cooled at a cooling rate of 1.5.degree. C./sec. or higher after completion of the rough rolling and until the initiation of finish rolling, and then completed with its final rolling above the A.sub.1 transformation temperature. A process for producing the above rolled steel is also disclosed.

Method of producing rolled steel having excellent resistance to sulfide

The present invention relates to low alloy steel and specifically to nickel-chrome-molybdenum steel. A low alloy steel having excellent stress corrosion cracking resistance containing C:.ltoreq.0.40%, Si:.ltoreq.0.15%, Mn:.ltoreq.0.20%, P:.ltoreq.0.010%, S:.ltoreq.0.030%, Ni: 0.50 to 4.00%, Cr: 0.50 to 2.50%, Mo: 0.25 to 4.00% and V:.ltoreq.0.30%, said Si, Mn and P being fulfilled with relationship of Si+Mn+20P.ltoreq.0.30%, the remainder comprising Fe and unavoidable impurities, the prior austenite crystal grain size being in excess of 4 of ASTM crystal grain size number.

Low alloy steel having good stress corrosion cracking resistance

There is provided a Ti-Mo alloy containing 0.2 to 3.0 wt % of molybdenum, with the balance being substantially titanium, characterized in that the amount of Fe in the impurities is not greater than 0.1% and the amount of O.sub.2 in the impurities is in the range that satisfies the following equation on the basis of the amount of Mo (%).

Titanium molybdenum alloy superior in resistance to pitting corrosion in

A method of minimizing corrosion deterioration and hydrogen absorption embrittlement of tantalum encountered in performing acid digestion of organic waste matter put in an acid digestion kettle of tantalum containing high temperature high concentration sulfuric acid includes the addition of nitric acid, nitrous acid, nitrates, nitrites and/or nitrogen oxides to the sulfuric acid bath.

Method of stabilized operation of acid digestion kettle of tantalum

A lubricant film which prevents galling or sliding metal surfaces comprising: a solid lubricant comprising 60-80% wt % of MoS.sub.2 or MoS.sub.2 +graphite; a lubricant additive comprising at least one component which comprises 10-30% wt % of Sb.sub.2 O.sub.3, Fe powder Zn powder or Ag powder; and an organic binder comprising 3-15% by weight of at least one component selected from the group consisting of epoxy ester resin, acrylic resin and urea resin.

Lubricant film for preventing galling of sliding metal surfaces

An efficient method of descaling metal sheets, such as titanium and stainless steel sheets, which includes carrying out anodic electrolysis using a metal sheet as the anode while sliding an abrasive member relatively to and on the surface of the metal sheet, is disclosed. The abrasive member essentially constitutes a fabric-like material made of synthetic resin.

Method of descaling metal sheets

A thin corrosion protective film of an iron oxide can be formed on the inner surface of a condenser tube made of a copper alloy by first applying on the inner surface a thin layer of an acidic suspension containing iron powder and then exposing the thus-coated inner surface to an atmosphere of an oxidizing gas. The above method can be carried out in a relatively short period of time and also in a relatively simple fashion. The resultant protective film is uniform and hardly reduces the thermal conductivity of the condenser tube, thus ideal as a protective film for condenser tubes of a heat exchanger.

Method for protecting the inner surface of a copper alloy condenser tube

A sacrificial anode for use in preventing corrosion of copper alloy parts and hydrogen absorption in titanium or titanium alloy parts of an apparatus useful for treating hot sea water, comprising a metal or metal alloy which maintains the potential of said copper alloy parts and titanium or titanium alloy parts serving as cathodes in said apparatus in the range of -0.5 to -0.65 V, relative to the potential of a saturated calomel electrode.

Sacrificial anode and apparatus employing same for treating hot sea water

This invention relates to a novel chemical apparatus, the inner surfaces of which are constituted by titanium material. The invention solves the problems of crevice corrosion and embrittlement of the material by taking in hydrogen, and discloses a method of solving such problems. The prior art methods of preventing crevice corrosion in apparatus prepared from titanium metal and also preventing the titanium of such apparatus from becoming fragile due to absorption of hydrogen include a method , in which an element of the platinum group is deposited on the surface of the titanium material and diffused thereinto. Alternatively, a Ti-Pd alloy is used as the material of the apparatus. Such methods, however, complicate the manufacture of the apparatus and are also disadvantageous in view of the cost of the great quantity of the platinum group element such as palladium which is consumed. In accordance with the invention, a mixed oxide layer, composed of an oxide of a platinum group element and an oxide of an anti-corrosion metal is provided on the surface, particularly, in the crevices of the titanium material of apparatus to achieve satisfactory prevention of corrosion and also prevention of hydrogen absorption. This method is very economical compared to the prior-art methods because the required quantity of the platinum group element is very small.

Chemical apparatus free from crevice corrosion

An electrolytic cell for use in various electrolytic treatments such as the sterilization of sea water includes a plurality of monopolar bar type electrodes, and an electrolytic solution filled in clearances between the electrodes. At least one group of electrodes disposed in the electrolytic cell is arranged so that one electrode is located at the center of an equilateral hexagon and the other electrodes are located at apexes of the hexagon.

Electrolytic cell with electrodes arranged as a hexagon

The invention relates to a novel chemical apparatus, the inner surfaces of which are constituted by titanium material. The invention solves the problems of crevice corrosion and embrittlement of the material by taking in hydrogen, and discloses a method of solving such problems. The prior-art methods of preventing crevice corrosion in apparatus prepared from titanium metal and also preventing the titanium of such apparatus from becoming fragile due to absorption of hydrogen include a method in which an element of the platinum group is deposited on the surface of the titanium material and difffused thereinto. Alternatively, a Ti-Pd alloy is used as the material of the apparatus. Such methods, however, complicate the manufacture of the apparatus and are also disadvantageous in view of the cost of the great quantity of the platinum group element such as palladium which is consumed. In accordance with the invention, a mixed oxide layer, composed of an oxide of a platinum group element and an oxide of an anti-corrosion metal is provided on the surface, particularly in the crevices, of the titanium material of apparatus to achieve satisfactory prevention of corrosion and also prevention of hydrogen absorption. This method is very economical compared to the prior-art methods because the required quantity of the platinum group element is very small.

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Kobe, Japan

Kazutoshi Shimogori