CN103614511B - Oxygen lance nozzle with complex structure - Google Patents

Abstract

The invention relates to the field of oxygen lances for oxygen blast at the top of a converter for steelmaking, and particularly relates to an oxygen lance nozzle with a complex structure. The oxygen lance nozzle comprises a red copper crown, and is characterized in that a 4-5mm H62 brass metal layer is brazed at the front end surface of the red copper crown, before brazing of the brass metal layer, the front end surface of the oxygen lance nozzle is cut by a machine tool so that the oxygen lance nozzle is thinner than the turning size by 4-5mm, then a layer of at least 6mm thick H62 brass is continuously brazed at the front end surface of the nozzle through brass welding wires at 400 DEG C-550 DEG C, then the nozzle is cooled down to room temperature, finally the outer surface of the nozzle is processed to be smooth and reach the design size through turning. Compared with the prior art, the oxygen lance nozzle has the beneficial effects that the high thermal conductivity of the red copper is kept, the strength and hardness of the surface of the nozzle are improved, and the steel slag adsorbed on the nozzle are reduced in production of the oxygen lance nozzle, so that the nozzle without being stuck with steel slag can be obtained and the service life of the oxygen lance nozzle is prolonged by 0.5 time.

Description

Oxygen lance nozzle with complex structure

Technical field

The present invention relates to oxygen lance for oxygen blowing field, converter steelmaking top, particularly relate to a kind of Oxygen lance nozzle with complex structure.

Background technology

In steel smelting procedure, oxygen gun blowing is absolutely necessary link, and oxygen rifle parts are foremost oxygen lance blow head.The quality of shower nozzle determines the quality of oxygen barotaxis energy to a certain extent, because it is directly inserted in more than 2500 DEG C of steel melting furnace, when oxygen blast, high speed oxygen air-flow is from solution in shower nozzle paranasal sinuses directive stove, stir to increase molten bath oxygen uptake degree to molten steel, decarburization, dephosphorization, desulfurization are carried out to molten steel, also causes a large amount of splashings of molten steel and slag simultaneously.

Molten steel up to more than 1700 DEG C and slag splash can be adsorbed onto nozzle surface, current oxygen lance blow head is all cast by pure red copper or is forged, mainly utilize high (the copper thermal conductivity 359.2 of red copper thermal conductivity, and iron thermal conductivity 66.7), the characteristic that heat conduction is fast, nozzle surface temperature is conducted rapidly to shower nozzle internal recycle water coolant, reduce shower nozzle bulk temperature whereby, theoretically in oxygen blast process, the molten steel splashed in stove is not easily bonded at the oxygen lance blow head surface that there is water coolant inside, but in actual production, the damage of shower nozzle is all because nozzle surface is by high-temperature molten steel absorption and corrosional, the major cause forming this phenomenon is that red copper and the weldability of iron when high temperature are better, iron and the atomic radius of copper when high temperature, crystal lattices type is all face-centered cubic lattice, ordination number, and the out-shell electron number of atom etc. relatively, the molten steel of high temperature spreads so can be formed between atom in moment and the red copper nozzle surface of low temperature, molten steel is fused on red copper surface.

Carbon atom contained in the high temperature iron that oxygen lance blow head adheres to, meets high speed oxygen air-flow and will to burn C+O ₂=CO ₂and the generation high temperature that releases energy, the copper wall corrode of shower nozzle is fallen, if the molten steel absorption in stove is less than on shower nozzle pileum, material is that the oxygen lance blow head of fine copper just chemical reaction can not occur with the oxygen penetrated at a high speed, but oxygen lance blow head structure cannot accomplish this point at present.

Summary of the invention

The object of this invention is to provide a kind of Oxygen lance nozzle with complex structure, overcome the deficiencies in the prior art, adopt composite structure, one deck high strength is welded at casting nozzle surface, the metal of non-stick steel slag again, keep out the shock of molten steel and the slag splashed in converter whereby, thus improve the work-ing life of shower nozzle.

For achieving the above object, the present invention is achieved by the following technical solutions:

Oxygen lance nozzle with complex structure, comprises red copper pileum, at the H62 brass wire layer of front end face soldering one deck 4 ~ 5mm of red copper pileum, before brazing brass metal, first use the front end face of machine cut oxygen lance blow head, make it to become the thin 4 ~ 5mm of size than car, shower nozzle machine has added laggard row shower nozzle assembly welding;

First welding portion oxide film is disposed before soldering, solid flux is sprinkled on surface, then pileum rush to put into electric furnace and be preheated to 400 ~ DEG C 550, DEG C insulation 20 minutes after, rotary table carries out soldering, welding material is brazing wire, welding sequence is by the progressively inwardly spiral step welding of shower nozzle end face ragged edge, welding torch rifle mouth and nozzle surface angle at 45 °, continuous rapid welding under the condition ensureing penetration, the height of filler metal layer is 5mm ~ 6mm, postwelding shower nozzle is put into insulation can and is cooled to room temperature, again the processing of shower nozzle outside surface is smoothed to size.

The trade mark of described brazing wire is HS221.

Described solid flux is the mixture be made up by weight percentage of following several feed composition: borax 60%, boric acid 30%, sodium hydrogen phosphate 10%.

Compared with the existing technology, the invention of the beneficial effect is: on the surface of pure copper oxygen lance nozzle brazing layer of brass to resist oxygen steel slag, makes the splashes of liquid steel can't stick on the nozzle surface covered with brass, does not fuse together, stick on the elimination of convenience, both using the heat conductivity of copper, the nozzle is always in a state of low temperature, and increases the strength and hardness of the nozzle surface, reduce oxygen lance nozzle in the production process of steel slag adsorption of nozzle, become a non-stick steel slag nozzle, nozzle due to the internal is pure copper, the surface of brass (H62), the joining together of two each metal itself characteristics in bad working environment, so as to improve the service life of the nozzle is 0.5 times more.

Accompanying drawing explanation

Fig. 1 is embodiment of the present invention structural representation.

In figure: 1-red copper pileum 2-brass wire layer

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described further:

See Fig. 1, it is Oxygen lance nozzle with complex structure example structure schematic diagram of the present invention, at the HS221 brazing wire metal level 2 of front end face soldering one deck 4 ~ 5mm of red copper pileum 1, before brazing brass metal, first use machine cut oxygen lance blow head front end face, make it to become the thin 4 ~ 5mm of size, other parts normal process than car, shower nozzle machine has added laggard row shower nozzle assembly welding;

First pileum welding portion motor wire brush is thoroughly disposed oxide film before soldering, sprinkle by the formulated solid flux of borax 60%, boric acid 30%, sodium hydrogen phosphate 10% component at pileum surface uniform;

Shower nozzle is put into electric furnace preheating by the direction then rushed to by pileum front end face, and the shower nozzle product preheating temperature wherein for below diameter phi 219mm is 400 DEG C, is preheated to 550 DEG C to the shower nozzle product of more than diameter phi 245mm;

In insulation after 20 minutes, shower nozzle is put into rotary table weld, pistol is hand-held medium size H01-20 type Ethylene Oxide flame welding torches, welding material is brazing wire, its trade mark is HS221, and its main chemical compositions is by weight percentage: copper Cu60%, silicon Si0.5%, surplus are zinc Zn.

The technological process of welding is as follows: welding flame adopts slight oxidation flame, welding sequence is by the progressively inwardly spiral step welding of shower nozzle end face ragged edge, welding torch is tried to get the first word in the angle at 45 ° with nozzle surface, operator holds welding torch hand and keeps posture constant, rotary table automatically rotarily drives welded shower nozzle vertically and rotates from left to right, touch with the fireworks whip graft of Ethylene Oxide oxydizing flame middle level and dissolve head body fine copper, another hand sends into melt tank edge the brazing wire being moistened with solid flux by bottom wire feed method, welding torch has rhythm to swing up and down, necessary rapid welding continuously under the condition ensureing penetration, filler metal height 5mm ~ 6mm, postwelding shower nozzle puts into insulation can, to be cooled to room temperature again with lathe by shower nozzle outside surface processing be smoothed to size.

The binary alloy that brass is made up of copper and zinc, brass has much higher intensity than red copper, hardness and erosion resistance, when brass welds with steel, because temperature of fusion differs greatly, brass fusing point is (HS221 brazing wire 880 degree), the fusing point of steel is 1540 degree, so can only soldering be used, melting welding cannot be carried out, solder flux must be used during soldering, solder flux Main Function makes oxidized metal reduction in melting process, remove the gas in weld seam and impurity, and form a kind of protective membrane on surface, deposite metal, increase the mobility of deposite metal, wettability, weldability, if do not used solder flux, brass and the steel of fusing are mutually exclusive, can not produce molten mutually, fuse welded together, according to this weld characteristics of brass, the shock of slag when oxygen lance blow head surface soldering one deck brass of fine copper resists oxygen blast, the molten steel splashed is made to glue on the brass that is covered with less than nozzle surface, also can not fuse together even if be stained with, it is convenient to eliminate, worked by shower nozzle time institute's thermal radiation of the high heat conductance so both maintaining red copper is conducted to internal cooling water, turn improve intensity and the hardness of nozzle surface, in minimizing production process, slag is to the absorption of shower nozzle, become the shower nozzle of non-stick steel slag, thus improve the work-ing life of shower nozzle.

Claims (2)

1. Oxygen lance nozzle with complex structure, comprise red copper pileum, it is characterized in that, at the H62 brass wire layer of front end face soldering one deck 4 ~ 5mm of red copper pileum, before brazing brass metal, first use the front end face of machine cut oxygen lance blow head, make it to become the thin 4 ~ 5mm of size than car, shower nozzle machine has added laggard row shower nozzle assembly welding;

First welding portion oxide film is disposed before soldering, solid flux is sprinkled on surface, then pileum rushes to and puts into electric furnace and be preheated to 400 DEG C ~ 550 DEG C, be incubated after 20 minutes, rotary table carries out soldering, welding material is brazing wire, welding sequence is by the progressively inwardly spiral step welding of shower nozzle end face ragged edge, welding torch rifle mouth and nozzle surface angle at 45 °, continuous rapid welding under the condition ensureing penetration, the height of filler metal layer is 5mm ~ 6mm, postwelding shower nozzle is put into insulation can and is cooled to room temperature, again the processing of shower nozzle outside surface is smoothed to size,

Described solid flux is the mixture be made up by weight percentage of following several feed composition: borax 60%, boric acid 30%, sodium hydrogen phosphate 10%.

2. Oxygen lance nozzle with complex structure according to claim 1, is characterized in that, the trade mark of described brazing wire is HS221.