海水に對して耐蝕性なる新輕合金クルミン (Chlmin) と既知輕合金との比較 (1)

概要

論文の詳細を見る
I. Aluminium light alloys are all very weak for sea water corrosion. Even Duralumin, the best rolling alloy, and Silumin, one of the best casting ones, are not good on this point. Some alloys are really noncorrodible but not used for their inferior mechanical properties and diffculties in casting, rolling or forging. A new alloy was invented in our laboratory 6 years ago, industrial researches were completed and the products are now used in some works. It was named "Chlumin" as it contains chromium, but a few per cent of magnesium and iron are also added. 2. Non-corrodibility. Castings of Chlumin and of an alloy of composition Cu 8%, Al 92%, the most common one, both made by metallic mould, were immersed in 5% NaCl solution. After 4 years' immersion Chlumin gave only little deposit retaining even some luster, while, the other was severely corroded precipitating considerable mass of aluminium hydroxide. The machined surfaces of Chlumin and Silumin plates were exposed to air being sprayed by salt water every day. Many black spots appeared on Silumin but Chlumin remained bright. Specimens were next immersed in 5% NaCl solution in separate bottles. The quantity of deposit and the weight decrease of specimen were measured aftea 40 days. Chlumin was a little better even than aluminium. Silumin, Y-alloy, Duralumin and all others containing Cu or Zn were attacked severely. Many test pieces of wire were immersed in 5% NaCl solution and the solution was renewed at times to expose them to air for a day to accelerate the corrosion. Chlumin and aluminium wires, annealed or not, lose scarecely their strength by 7 months' immersion. The elongation decreases in some cases. While, Duralumin, variously heat-treated or not, loses both qualities rapidly. After 5 months the strength reduces to 80 to 20% of the original value and the elongation to 50 to 20%. 3. As a casting alloy. Chlumin is a little inferior to Y-alloy in strength and yie'd point but is superior to it in elongation and impact resistance. It is better than Silumin in every respect and is more easy to cast and safe to use as no special process (modification) is wanted on manufacturing. Any complex form can be cast resisting to severe water pressure test. Pistons of internal combustion engine and parts of electric motor have been used for more than a year with better result than Y-alloy. 4. As a rolling alloy. Wires of Chlumin were compaced with those of aluminium and Duralumin being annealed at various temperatures. Duralumin aged after quenching from 510℃ into water is exeedingly good indeed when annealed at temperaturs below 200°, but becomes worse than Chlumin at 300°. Besides, it may not be a safe process of manufacturing to quench an alloy of melting point of 620° from above 500°. It may be very difficult to heat a large article uniformly above 500°. A little overheating will set in local melting ; and when the temperature is too low some parts mu t meet the worst heat-treatment. Heatin on welding will spoil the good properties given by quenching and aging and it is often impossible in practice to quench the article again. Quenched Duralumin must le worked in a few hours as it hardens with time. This is a very inconvenient property and unduly treatment unavoidably some times applied in practice will spoil the mate ial. Thus, Duralumin in actual use will not always have the best properties. Chlumin, on the other hand, needs no heat-treatment. Taking these circumstances all into account it may be concluded that Chlumin is equal in mechanical properties with Duralumin. Thin plates, wires and articles of complex form are easily made by rolling, drawing and forging. 5. Conclusions. "Chlumin" has a small density of 271. In resistance to sea water corrosion it is superior to any known light alloys. In mechanical properties it ranks among the best. It is suitable both for casting and rolling materials. It can be cast easily, machined well and stands to severe water pressure test. As cast it has better mechanical properties than Silumin and Y-alloy and is more anti-corrosive The product is safe as it needs not any special process (modification) on casting. As a rolling material it can be worked more easily than Duralumin, equals with it in mechanical properties and far surpasses it in corrosion. It needs no heat-treatment so is safe to use. It is twice as strong as commercial aluminium and resists better to sea water attack.
社団法人日本鉄鋼協会の論文
1931-09-25

著者

飯高一郎
早稻田大學:附屬鑄物研究所

海水に對して耐蝕性なる新輕合金クルミン (Chlmin) と既知輕合金との比較 (1)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク