PL4639B1

PL4639B1 - Steel alloy.

Info

Publication number: PL4639B1
Application number: PL4639A
Authority: PL
Filing date: 1925-04-18
Publication date: 1926-05-31

Description

Znane sa stopy stali, odznaczajace sie wielka odpornoscia przeciw dzialaniu at¬ mosfery i kwasów, zawierajace oprócz ze¬ laza chrom w ilosci ponad 8% i wegiel w ilosci do 1%, Naogól stosuje sie dodatek chromu 12—20%, a zawartosc wegla do 0,5%, Stopy te nazywa sie zwykle nierdze- wiejaca stala (Stainless Stell), Wiadomo, ze odpornosc przeciw kwa¬ som i czynnikom atmosferycznym (nazy¬ wano krótko odpornoscia na rdzewienie), zmniejsza sie bardzo, gdy zawartosc wegla jest wyzsza od 0,5%, Wade te usuwano za- pomoca domieszki niklu w ilosci np, 3 do 10%, jednak wada tych stopów jest to, ze stopy o duzej zawartosci niklu wymagaja zmudnej obróbki termicznej, aby umozliwic obróbke zimna tej stali, która jest bardzo twarda. Oprócz tego domieszka niklu ogra¬ nicza moznosc stosowania takiej stali, szcze¬ gólnie do wyrobu narzedzi tnacych. Znana stal chromowa lub chromowo-niklowa nie jest odporna na dzialanie kwasu azotowe¬ go z dodatkiem kilkoprocentowym alkalji.Takze kwas solny i pruski nagryza wspo¬ mniana stal stosunkowo latwo. Jako nie¬ wrazliwe na te dzialania znane sa stale chromowe z domieszka molibdenu, które jednak nie sa wlasciwie stala, lecz zelazem, bo zawieraja tylko okolo 0,05% wegla.Stopy te sa dostatecznie odporne na dzia¬ lanie kwasów i mieszanin kwasów z alka- ljami, zwlaszcza z chlorkiem alkalicznym w ilosci przewyzszajacej 5%, lecz jako sto¬ py zelaza maja te wade, ze nie daja sie hartowac-Próby wykazaly, ze mozna uzyskac sto¬ py stalowe dobrze*%artowane, nierdzewie¬ jace, posiadajace cUaza wytrzymalosc, da¬ jace sie dobrze obrabiac mechanicznie i znacznie wiecej odporne na dzialanie kwa¬ sów i mieszanin kwasów, niz znane dotad stopy, jezeli do znanych stopów stali, za¬ wierajacych 8—25% Cr i 0,1—1,2% C, do¬ da sie jeszcze molibden w ilosci 0,2—6%.Mangan i krzem moga byc zawarte w zwy¬ klych dotad ilosciach. Wymieniony stop opiera sie przez dlugi czas nawet dzialaniu wrzacej mieszaniny kwasu azotowego i siarkowego.Wymieniony stop, zawierajacy wiecej niz 15% Cr, wegla ponizej 0,5% i molib¬ denu az do 3%, daje sie latwo kuc. Przy wyzszych zawartosciach wegla i molibde- denu plastycznosc jednak zmniejsza sie.Wade te mozna usunac przez dodanie 0,5 do 2% Ni lub 0,5 do 2% Co, albo przez dodanie obu tych domieszek w ilosci nie- przekraczajacej razem 3%. Dodatek ten nie wplywa niekorzystnie na odpornosc przeciw rdzewieniu, natomiast struktura stopu staje sie drobniejsza, a wlasnosci me¬ chaniczne, zwlaszcza wytrzymalosc na ciagnienie, znacznie sie polepszaja. Stopy zawierajace powyzej 0,2% daja sie harto¬ wac, a zawierajac okolo 0,5% C nadaja sie do wyrobu narzedzi tnacych. W stanie wy¬ zarzonym stop taki daje sie dobrze obra¬ biac, prasowac, walcowac na cienkie bla¬ chy i wyciagac na zimno w cienkie druty.Poniewaz odpornosc przeciw rdzewie¬ niu zalezy od czystosci stali, konieczne wiec jest jej dokladne odtlenienie. Okaza¬ lo sie, ze bardzo dobrze jest dodac w tym celu do plynnej stali do 1% wanadu lub tytanu.Próby wykazaly, ze opisany stop nada¬ je sie równiez do odlewania róznych przed¬ miotów, np. naczyn. Aby zwiekszyc jeszcze bardziej odpornosc takich naczyn na dzia¬ lanie wysokiej temperatury mozna powiek¬ szyc zawartosc chromu, az do 50%, molib¬ denu do 10%, a kobaltu lub niklu, albo obu razem az do 15%. I w tym wypadku doda¬ nie do 1% wanadu lub tytanu do plynnej stali, wplywa na jej oczyszczenie i zwiek¬ szenie odpornosci przeciw dzialaniu kwa¬ sów. PLThere are known alloys of steel, which are highly resistant to the action of the atmosphere and acids, containing, in addition to iron, more than 8% of chromium and up to 1% of carbon. Generally, an addition of 12-20% is used, and the content of carbon is up to 0.5%. These alloys are usually called non-rusting steel (Stainless Stell). It is known that the resistance to acid and atmospheric agents (called for short rust resistance) decreases greatly when the carbon content is higher than 0.5%, these defects were removed with nickel admixtures, e.g. 3 to 10%, but the disadvantage of these alloys is that alloys with a high nickel content require tedious heat treatment to enable cold treatment of this steel, which is very hard. In addition, the admixture of nickel restricts the use of such steel, particularly in the manufacture of cutting tools. The known chromium or chromium-nickel steel is not resistant to the action of nitric acid with the addition of a few percent alkali. Also hydrochloric acid and Prussian burn the said steel relatively easily. Chromium steels mixed with molybdenum are known to be insensitive to these effects, but they are not actually solid, but iron, because they contain only about 0.05% carbon. These alloys are sufficiently resistant to the action of acids and mixtures of acids with alkali. - irons, especially with alkali chloride in an amount exceeding 5%, but as iron alloys they also have the disadvantage that they cannot be hardened - Tests have shown that it is possible to obtain steel alloys well-grounded, non-rusting, and having zinc strength, easily machinable and much more resistant to the action of acids and acid mixtures than the known alloys of the known steel alloys, containing 8-25% Cr and 0.1-1.2% C, a molybdenum content of 0.2-6% will also be added. Manganese and silicon may be present in previously customary amounts. The said alloy resists for a long time even the action of a boiling mixture of nitric and sulfuric acid. Said alloy, containing more than 15% Cr, less than 0.5% carbon and up to 3% molybdenum, is easily crushed. With higher carbon and molybdenum contents, however, the ductility is reduced. These defects can be removed by adding 0.5 to 2% Ni or 0.5 to 2% Co, or by adding up to 3% of the two together. This additive does not adversely affect the anti-rust resistance, while the alloy structure becomes finer and the mechanical properties, especially the tensile strength, are significantly improved. Alloys containing more than 0.2% can be hardened, and alloys containing about 0.5% C are suitable for making cutting tools. In the deposited state, such an alloy can be well worked, pressed, rolled into thin sheets and drawn cold into thin wires. As the rust resistance depends on the purity of the steel, it is necessary to deoxidize it thoroughly. It turned out that it is very good to add up to 1% of vanadium or titanium to the liquid steel for this purpose. Trials have shown that the described alloy is also suitable for casting various objects, for example dishes. To increase the heat resistance of such vessels even more, the content of chromium can be increased up to 50%, molybdenum up to 10%, and cobalt or nickel or both up to 15%. Again, the addition of up to 1% of vanadium or titanium to the liquid steel has a cleaning effect and increases its resistance to acid attack. PL

Claims

Patent claims. 1. An alloy of high resistance to chemical attack, high strength and hardenable steel, characterized by the fact that in addition to iron it contains 8-25% Cr, 0.1-1.2% C and 0.2-6% Mo.

2. Steel alloy according to claim 1, the significant point is that, in order to improve the plasticity of the alloy, another 0.5-2% Ni or 0.5-2% Co or both components are added in a liquid state in an amount not exceeding 3%.

3. Steel alloy according to claim 1, the significant fact that 1% of vanadium or titanium is added to the liquid steel.

4. Steel alloy according to claim 1, the significant point is that the addition of chromium is increased up to 50%, and the addition of molybdenum up to 10%, in order to achieve fire resistance.

5. Steel alloy according to claim 1-4, characterized by containing up to 15% Ni or Co, or Ni and Co together up to 15%. Glockenstahlwerke Aktiengesellschaft vorm. Rich. Lindenberg. Deputy: M. Kryzan, patent attorney. Print by L. Boguslawski ^ WarSzowci. PL