SU1109570A1 - Process for manufacturing graphite crucibles for melting titanium - Google Patents

Abstract

1. METHOD OF MANUFACTURING GRAPHITE TIGLES FOR MELTING TITANIUM, for example, in skullcaps, including applying a coating of refractory and heat-resistant material on the inner working surface of graphite crucible, characterized in that, to increase the service life of the crucible, to improve the mechanical properties of castings and moldings, the moldings of moldings and moldings castings of refractory materials are used in order to extend the life of the crucible, improve the mechanical properties of castings and molds. crucible from crucible, coating is applied from titanium alloy containing 3-15 May. / o oxygen, and subjected to subsequent saturation with carbon to 0.1-3 Mac.Vo2. The method according to and. 1, characterized in that the titanium alloy with oxygen is deposited with a thickness of 0.1-0.5 mm on the surface of the crucible previously heated to 250-300 ° C by means of a gas-flame metallizer. 3. Method according to paragraphs. 1 and 2, characterized in that the coating is saturated with carbon from a graphite crucible by melting a deposited layer of titanium-oxygen alloy with an electric arc from a non-electrode at a current density of A / cm under vacuum at an arc pressure of-e i Hg. or inert gas of one gas. (L

Description

with

C71 The invention relates to a special electrometallic HHH associated with the production of shaped castings from titanium-like snlavs in arnisage grades. The use of meta; lly crucibles; and 1 titanium with a water cooling because of localization: 1 penetration of the walls of Tiii.is; It leads to the fact that the skull is not Bccr; ia can be removed from the crucibles and the possibility of contamination of the melt by the material cannot be ruled out, but the main thing is that there is an increase in the explosive concentration of the casting unit. The various systems of sensors, alarms and interim thermal transfer cavities with inert gases cannot guarantee the safe and stable operation of the installation due to the presence of very high tensile stress, since the ground pressure is 111 and the current is legal 20 A / cm and BLjiuie, and also because the time of the yeast does not exceed a few microseconds. Crucible knots with 1 raffle embossing are safer from burn-through and therefore have found wide application in nromine. However, the presence of graphite G1) is a very uncommon requirement for the technology of the casting process, in terms of stabilization and maintenance of the skull to the optimal limits, due to the potential for randomization; Lk icji is the chemical titanium nrigorenium titanium and graphite surround; the remaining (unresolved task of the freedom of the remaining 1) is removed from the crucible. The known method of making rpaip-i crucibles for melting titanium and its CH.i.iov, Vk; tsayaytsyy deposition on BHyrpeiHiioio working surface of graphite tpgl niro.lyticheskogo carbon and carbide i; tanna 1. The use of lime | dl l b I melting various but the chemical composition of titanium snlavs, especially in the production of CTBCHm ix conditions, is limited and overwhelmed, there is no knowledge of the absence of large crucibles in domestic metallurgical and foundry nrominlennog nazmacheni pyrolytic carbon. carbon from the gas phase and the high cost of this process. A thin surface layer of titanium carbide (3-6. Micron) can be e (|.) (() Efficient and workable for one or two peated titanium melts. However, a very thin surface layer of titanium carbide readily oxidizes and dissolves in titanium and the eio positive effect quickly disappeared. -ia 1a.lnchn x i.micheskoi) pri1ara. PoE; OU1 thin), pdnom pokr1, years i dvdovboBo) lob (.m, nr. Gb vlemyy kom pok:) yyyi m g |); l 1ilO1I) 1x about; 1itsovok ll-ilei |: romplenlen1x 1 garisazhnykh nechei (doslupn () C1l and ease of application , chemical resistance to titanium in the process of nack (“Ten highs, high long-term durability of oxidation type), without loss: i;: ninTiibix properties cannot. 1aiGx) more b ;, ..:; kim for technical sluchuic and Ach.ch (.1My effect method 1: 31ol; 1En1i rafilov lx crucible for c, titanium batches, including on the internal working surface gra (}) of itChWL crucible of a heat-melting coating; karostoykogo (in matsria.la. As a characteristic of the inadequate. melting material.pso.l1) 3ls; t oxide) bsrn, l, li. and D.LYA replies;); The interaction of titanium with oxide beryllium on a carbon layer (beryllium is applied to nitrite oxide 1-1. low durability, coating and melt contamination with coating material. TS.N) H} is invented; (there is 1 e; p1cheiiue of the life of the crucible, H () of the fur of the CI oys (garlic and light ni / on, eecii of the extraction of ar1n-; soot iri Llg.l. i (xg1av.le1-pa tse, eh dostngaelch lh-m, that cnr / iaciio method was manufactured by 1p (() T: ir; ieiii d, l melting of titanium, in | |; Pszansh51x furnaces, including lyuchemuhmiiip / TOeninoio working poverG) X1-k; st pokrggi from thl (.1P, lajarogtoykogo materpa ,, pokr) tpe alloy lgga1: a, containing keplodorod, n under jurga village of telun, c him to your carbon with carbon up to 0.13 ma.- / with 1 syllable;. titanium with acid.chloro. l put that lp1, 0.1-- 0.5 m. 1 pa ndvarilier heated up to 25 () - 300 (1 surface of l1l. l with nomosy gas-flammable glass, l, l1 of tanning, piped1 use lerode of oste1cest) are smelted from grafnly crucible oil.pressure of naneceHfioio of ti-tlo alloy with l, l | .K) house of electric arc) from ne |) ashodu.myogo elekrod i) n p.volpost in liaKvvMe first and second pressure gas. Haneccinic sp.laa tptapa are equipped with pulsam wire buckle wire type BT-1-00 e using 1-phase metalizers mshi MGI-2, MG-4 or. Or, working on aHeiiL eiie in oxidized lye gas. (5 as an oxidizing agent, oxygen and air are used.

A layer of titanium alloy is applied on a graphite surface heated to 250300 ° C. Carbonization of a coating of 1 t of si, 1a on the surface of a gra () 1t crucible, is carried out by heating it from a graphite or tungsten electrode at a current density of 5-8 A / cm under vacuum at a residual pressure of MO-IlO mm Hg. Art., or inert gas. As a result of carbonization, the inertness of the tptane alloy with oxygen increases and the titanium skull does not stick to the coating. As a result of carbonization, a qualitatively new protective coating is formed, which impregnates the surface layer of a porous | -raffit lining to a depth of 3-5 mm and improves the operational durability of the crucibles by creating a heat-resistant and iie-prone coating over the entire working surface of graphite lining. Xu silawa tptaia with acid toltsi1 || oy less than 0.1 mm does not allow s / sufficient reliability to provide high-quality protection to the working surface of graphite tpgl due to the increased graphite iorost of the arc, which can be crushed by eio. A layer of more than 0.5 mm in the process of heating the electric arc (due to low tennoprovodpity and relative1) Io large tolsp1s1 gives cracks and peels off from graphite to decompose;

Heating gra ()) imitation cladding before coating is darker), gives a low degree of stai; 1e; 1i and s. Meta.isation layer m. As the temperature rises above 300 (irreducible to the oxide of 1x1K) of graphite, the contact with the meta, liziatsioppym layer is disturbed due to the beginning of the formation of CO or COz, dusting | s.tai is porous and strongly za: .d) waipy. The melting point of the alloy with oxygen at a current density of less than 5 L; cm leads to unequiometric carbonation, carbon depletion and an increase in arc treatment time. The coating may b) 1 low quality porous. With an increase in current density above 8 A / cm, a layer of oxycarbide uniform in thickness cannot be obtained, and the presence of high pressure during discharge causes local thinning or influx of the metallization layer, which, ultimately, adversely affect the heat-accumulating and heat-shielding properties protective layer

Application or inert environment warns iov1) Full oxidation of the zandit film. With a pressure of IlO mm Hg. Art. during the heating process, the electrode is oxidized, which leads to its excessive oxygenation and

 chopped properties. The following are given / kmsh beyond the limit, IlO mmHg. Art. Not me, because the properties of the coating do not change, but d.1ito, the first processing will return the same.

The quality of the titanium to be boosted is due to the penetration of the gas, the cover, which reliably prevents pacH.iaB from interacting with gases, 10 CONSTANTLY present in the pores of the TNG, 1 even in the order of .m Hg, Art.

Example. Pa ob-shchtsovka, made of grams (() ita brand EG-1, using a gas metal valve, I work 1, his pa anern, iene with oxygen, put a layer of Tirrana with oxygen (9 wt./o) large 0.2 lm. As a meta.1lnzatsponnoy charge nenolut nrovo, 1ku with a diameter of 1.6 mm from alloy VT-1-00, however, its feed rate is 15 m / min. The pressure of air with oxygen for sputtering b. ; 1 penetrator from the surface of plastic pipe 200-250 mm. Graphite tigue.i, heated before 1Tsm heated to 300 ° C in an P-85 furnace 11 heat-treating. After applying meta,:; e, 1b are set in | -Ar11Crash1 and Peva-2, wak) are also dazzled and coated with 11th non-consumable graphite section of the 1.1 electrode, and 1v; 11ost 11 of current 7.L / cm and residual field of about 1-10 mm. . Art.

(d; lava tptana with oxygen in the liquid state produces lining of the crucible) 3.5 mm li is heated with an angle of up to i.5 wt ..1.1 and condition of the type ii.iaBOK. In: 11nursed but well-known and, in one way, ngivedeny in the table.

The 11th whilst DYP |, 1e proves that the quality of meta, 1., B1; w, 1 found in graphite, 1, 2, produced by the proposed method, greatly exceeds the quality of the metal, melting,: content harmful npiiMCceii. and according to the plastic characteristics, vi1,1 a, of a metal, with operational durability, which is more than 3 times as resistant as a crucible. Moreover, a skull of graphite cladding, tig.1., Is easily expressed, and T111 is a single unit, 1, and, firstly, a tivochnogo installation is suitable for n spurs, other types of chemical composition, which is bo, 1 time value. production conditions of casting. Thus, the proposed method for the manufacture of graphite crucibles for garnetting titanium smelting makes it possible to increase their service life by 23 times, since it is the shortest time for the furnace when changing crucible.1, and the cost of expensive titanium is reduced; iia flush melting when moving from one brand of heat to another, to reduce the marriage

molded casting on plastic; m. characteristics associated with G1 (). 1 contamination by harmful impurities.

Claims (3)

1. METHOD OF MANUFACTURE GRAPHITE TIGLES FOR MELTING TITANIUM, for example, in skull furnaces, including applying a coating of refractory and heat-resistant material to the inner working surface of a graphite crucible, characterized in that, in order to increase the life of the crucible, increase the mechanical properties of castings and facilitate the extraction of the skull from the crucible, the coating is applied from an alloy of titanium containing May 3–15. % oxygen, and is subjected to subsequent carbon saturation up to 0.1-3 wt. ^a / ₀ . 2. The method according to π. 1. characterized in that. that an alloy of titanium with oxygen is applied with a thickness of 0.1-0.5 mm on the surface of the crucible preheated to 250-300 ° C using a gas-flame metallizer. 3. The method according to ini. 1 and 2, characterized in that the coating is saturated with carbon from a graphite crucible by melting a deposited layer of a titanium alloy with oxygen by an electric arc from a non-consumable electrode at an arc current density of 5-8 A / cm ² in vacuum at a pressure of not higher than E10 ¹ mm Hg . or in an inert gas environment. 09570