Crucibles are now used in many industries, especially in graphite crucibles. How much do you know about them? Next, Xiaobian will explain in detail:

1、 & nbsp; carry

Special handling tools must be used to handle the crucible, and it is not allowed to roll the crucible directly on the ground. Collision shall be avoided during handling to avoid damaging the glaze layer and thus affecting the service life of the crucible.

2、 & nbsp; storage

The crucible must be stored in a dry and ventilated place, preferably on a wooden bracket. Avoid usingGraphite crucibleIf it is directly placed on the brick, soil or cement floor, the crucible will be damped, which will lead to the glaze layer, thus reducing the melting efficiency and service life of the crucible, and even the bottom will fall off in serious cases.

3、 & nbsp; Product usage specification

1.  Preparation before installation:

1.1 check whether the inner wall and bottom of the crucible are intact.

1.2 check whether there is residual slag in the furnace, and if so, remove it in time.

2.  Select the correct crucible base

2.1 the crucible base shall have the same shape and slightly larger size (about 2cm) as the crucible bottom.

2.2 for different types of crucible furnaces, crucible bases with appropriate height shall be selected.

2.3 avoid using waste crucible base, otherwise the crucible life will be greatly shortened.

3. Installation and fixation of Crucible:

3.1 install the crucible for fuel gas or oil: first place the crucible on the base and thenGraphite crucible for melting aluminumA certain expansion space for the crucible shall be reserved between the crucible and the top of the furnace wall, and fixed with wood blocks, cardboard and other materials. Adjust the position of burner and nozzle to make the flame aim at the combustion chamber instead of directly aiming at the bottom of crucible.

3.2 installation of crucible for rotary furnace: support bricks shall be used to fix the crucible on both sides of the crucible nozzle to avoid wedging the crucible tightly. At the same time, about 3-4mm cardboard and other materials are placed between the support brick and the crucible as the pre expansion space of the crucible.

3.3 installation of crucible for electric furnace: the crucible should be placed in the center of the resistance furnace, and the bottom of the crucible should be higher than the lowest row of heating elements. At the same time, heat preservation cotton is used for sealing between the top of the crucible and the furnace edge.

3.4 installation of crucible for induction furnace: ensure that the crucible is placed in the center of the induction coil to avoid local overheating and cracks.

4. Crucible preheating:

Preheating the crucible in a correct way can greatly prolong the service life of the crucible.

4.1 according to different types of crucible furnaces, when using the crucible for the first time, preheat the crucible to about 200 ℃ in 30 minutes without adding materials, and dry it for 60 minutes. The purpose is to volatilize the absorbed water on the surface of the crucible. Prevent cracking at the initial stage of use.

4.2 after preheating, the crucible shall be heated to 900 ℃ - 1000 ℃ (about 2 hours) as soon as possible, and kept for 20-30 minutes, and then raised or lowered to the working temperature. The purpose is to quickly pass through the oxidation temperature region of the graphite crucible.

4.3 after the first preheating, the crucible usually does not need to be preheated again, unless the crucible is wetted again. (the crucible must be preheated again after each shutdown.)

5. Feeding:

5.1 metal materials must be dried before being added.

5.2 when feeding, it shall be put down gently. It is not allowed to throw or pour the metal ingot into the crucible to avoid damaging the crucible.

5.3 put the metal ingot into the crucible vertically, and keep enough expansion space between the metal ingot and the crucible wall. Do not put the metal ingot in the crucible horizontally, so as to avoid the expansion of the metal ingot after heating and damage the crucible.

5.4 some small pieces of metal materials can be added into the crucible to pave the way for large ingots.

5.5 during continuous melting, part of the metal solution can be retained in the crucible to accelerate the melting speed. However, it is necessary to avoid adding large metal materials to a small amount of solution, so as to avoid sudden cooling or solidification of the solution and damage to the crucible.

5.6 when adding liquid metal, avoid overfilling, and generally do not exceedHigh purity graphite crucible80% of capacity.

6. Use of additives

When using the additive, it must be operated in strict accordance with the operating instructions of the additive.

6.1 additives can only be put in after the metal materials are completely dissolved. It is not allowed to put additives into the empty crucible or solid metal materials, nor to make the additives directly contact the crucible wall or outer edge, otherwise the crucible will be directly damaged.

6.2 when additives are used, they must be added in strict accordance with the specified dosage. Excessive use of additives will greatly shorten the service life of the crucible.

7. Use of crucible pliers

7.1 the size of the crucible clamp must match the size and shape of the crucible, and the upper edge of the crucible must not be squeezed to avoid damage to the crucible or safety accidents.

7.2 the crucible clamp shall be clamped at the middle and lower part of the crucible. If it is too high, it is easy to fall off or damage the crucible. If it is too low, it is not conducive to the operation during pouring.

7.3 when using the crucible to move the hot crucible, the crucible should be placed on the high-temperature resistant plate or the transfer tool, and the hot crucible should not be placed on the cold surface to avoid damage to the bottom of the crucible.

8. Pouring

When pouring with a crucible, it shall be carried out in strict accordance with the operating specifications to avoid damage to the crucible.

8.1 when the metal solution reaches the predetermined casting temperature, pouring shall be carried out as soon as possible after slag and gas removal.

8.2 during pouring, heating shall not be continued to avoid gettering, metal burning and uneven corrosion of the crucible wall, thus shortening the service life of the crucible.

8.3 when rotating crucible furnace is used, the crucible shall be restored to its original position after one pouring operation.

8.4 the metal solution shall not be kept in the crucible for too long, otherwise the service life of the crucible will be shortened and the quality of the melted metal will be reduced.

9. Empty the crucible

9.1 if the use of the crucible needs to be temporarily stopped due to slag removal or crucible furnace maintenance, the molten metal in the crucible shall be emptied.

9.2 when emptying the crucible, the molten metal in the crucible can be poured into the mold (material tank) to form ingots for later use.

9.3 if the molten metal is left in the crucible to solidify, the crucible will be directly expanded due to expansion during the next heating.

10. Remove slag

During the melting process, the additives and impurities in the metal solution will form slag and adhere to the crucible wall. Since the slag contains additives, which will corrode the crucible wall, the slag should be removed once a day.

10.1 special tools shall be used to remove the slag, and the slag shall be removed in time before solidification. The solidified slag will be difficult to remove.

10.2 avoid scratching the crucible wall when removing the slag.Graphite crucibleService life of.