JPH06128665A - Improving agent for metallurgy - Google Patents

Abstract

PURPOSE:To obtain a composition for metallurgy improving the mixture of gas, the existence of inclusion and the heterogeneity of metallic structure by executing heating treatment to the mixed material of iron sulfide powder and silicate-lime powder. CONSTITUTION:The iron sulfide powder and the silicate-lime powder are mixed desirably by wt% of 8-6 : 2-4. This mixed material is desirably heat-treated at 450-650 deg.C for 3-5 hr to obtain the composition for metallurgy. Into this composition, carbon, silicon, aluminum, silica oxide, aluminum oxide, ferrous oxide, iron, ferro-manganese, fluorite, silicon carbide, etc., are blended to obtain an improving agent for molten metal to iron, aluminum, copper, etc. By adding a little quantity of this improving agent into the molten metal, a cast product having a little oxygen and inclusion contents and uniform metallurgical structure is obtd. Further, this composition is effectively used for the improving agent for coated electrode, improving agent for steelmaking, improving agent for powder metallurgy, deflective strength improving agent for powder metallurgy, etc.

Description

Detailed Description of the Invention

The present invention relates to a composition for metallurgy, a molten metal for casting, a welding rod, a molten metal for steelmaking, and powder metallurgy for deoxidation (degassing), inclusion removal, soundening (homogenization) of metal structure, machinery. The present invention relates to an improving agent that imparts properties improved in terms of physical properties (tensile strength, transverse rupture strength, hardness, etc.).

[0002]

2. Description of the Related Art In the field of metallurgy, especially in the field where a raw material metal is once in a molten state or heated to be processed,
Common problems include mixing of gases such as oxygen, nitrogen, and hydrogen, the presence of unnecessary inclusions, and inhomogeneity of the metal structure after solidification.

For example, in the field of casting, it is particularly important to remove gases such as oxygen (usually referred to as deoxidation) in molten metal and to improve the soundness (homogenization) of the metal structure after solidification. Conventionally, carbon, silicon, etc.
Powders of simple substances or compounds such as copper and aluminum are added, and Fe-Si, Ca-
An inoculum containing Si as a main component is used.

Further, in the field of steelmaking, the removal of inclusions of oxides such as SiO ₂ has been a particular problem, and since clean steel containing few inclusions can be obtained, it is possible to remove Si, P, and S-removing agents. The use of a deoxidizing agent for the purpose of charging and deoxidation, molten steel stirring by electromagnetic stirring, and vacuum degassing methods are adopted.

Further, in the field of welding, it is difficult to weld high alloys, castings, aluminum and dissimilar metals, and the advent of welding rods that facilitate these weldings is desired.

In the field of powder metallurgy containing ceramics, the particle size, shape, mixing ratio, sintering conditions, etc. of the powder used have been devised to bring about some effects. Improvement is desired.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a metallurgical composition capable of solving all of these problems, which have long been a problem in the field of metallurgy, at once, a metal melt improver, and a covered arc welding rod. It is an object of the present invention to provide an improving agent for steel, a deoxidizing agent for steelmaking, and a bending strength improving agent for powder metallurgy.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that a treatment composition obtained by heating a mixture of iron sulfide powder and silica stone powder is contained. It has been found that various properties are improved in the metallurgical field when the above composition is used, and the present invention has been completed.

That is, the present invention relates to a composition obtained by heat-treating a mixture of iron sulfide powder and apatite powder, and a metallurgical improving agent containing the composition.

[0010]

FUNCTION AND EXAMPLE The feature of the present invention resides in the use of a treatment composition obtained by heat treating a mixture of iron sulfide powder and apatite powder. The reason why such a treatment composition is effective is not yet clear, but iron sulfide alone, silica stone alone, or even a simple mixture thereof has no effect.

As the iron sulfide powder, ferrous sulfide (Fe ₂
Either S) or ferric sulfide (FeS) may be used, but ferric sulfide can be preferably used in terms of price, availability, and the like. The particle size of the powder is preferably about 100 to 300 mesh, more preferably about 150 to 200 mesh.

Silica stone is a cyclosilicate of calcium, iron and manganese, which is also called wollastonite. In the present invention, the particle size is about 100-300 mesh, preferably about 15
Those having a mesh size of 0 to 200 are preferably used.

The mixing ratio of iron sulfide powder and silica stone powder is
The weight ratio is 9 to 5: 1 to 5, preferably 8 to 6: 2 to 4. Outside this range, the desired properties tend to be difficult to obtain. The heat treatment temperature is usually 300 to 750 ° C., preferably 450 to 650 ° C. If the temperature is too low or too high, the reaction tends to be incomplete. The treatment time varies depending on the intended use and purpose, but is usually 1 to 10 hours, preferably 3 to
5 hours.

The metallurgical improver of the present invention is prepared by blending this treatment mixture. Particularly, it is a metal melt improver for castings, a core wire treatment and coating for welding rods, a deoxidizer for steelmaking, and powder metallurgy. It exhibits an excellent improvement effect as a transverse rupture strength improver and the like.

For example, when it is used as a metal melt improver for casting, it has an excellent deoxidizing effect, a soundening (homogenizing) effect of the metal structure, and the inclusions are reduced. The metal melt improver is, in addition to the treatment mixture, carbon powder, silicon powder, aluminum powder, silicon oxide powder, aluminum oxide powder,
It is preferable to blend one or more of ferric oxide powder, iron powder, ferromanganese powder, fluorspar, and silicon carbide powder.

When the target metal is cast iron, as an example, the treatment mixture is 15 to 40% (weight%, the same hereinafter), preferably 20 to 35%, carbon powder 7 to 12%, preferably 9 to 9. 10%, silicon powder 0.5-2.0%, preferably 1.0
~ 1.5%, aluminum powder 0.2-0.7%, preferably
0.4-0.5%, silicon oxide powder 2.0-4.0%, preferably
2.5-3.5% and aluminum oxide powder 0.5-1.2
%, Preferably 0.7-1.0%. If necessary, ferric oxide powder may be added as a filler. Further, as another example, for example, the treatment mixture 15 to 45%, preferably 20 to 40%, iron powder 20
~ 40%, preferably 25-35%, ferromanganese powder 4 ~
10%, preferably 5-8%, fluorite 2-8%, preferably 4-6%, silicon carbide 5-15%, preferably 7-13%, ferric oxide 5-20%, preferably 7 It is also preferred to have a composition of -15%. In combination with the treatment mixture, the components other than the treatment mixture have a particularly excellent effect on deoxidation of molten iron, removal of inclusions and restoration of the metal structure after solidification.

The metal melt modifier is 0.1 to 0.7 when the treatment mixture is contained in an amount of 20 to 35% based on 100 parts by weight of the metal melt.
It is preferable to add parts by weight, preferably 0.3 to 0.5 parts by weight. When the amount is too large, it is not economical even if it is not harmful, and when the amount is too small, it tends to be unlikely to be effective.

There are various methods of adding the metal melt improver. For example, it is easy and uniform to mix the improver in a can made of steel and to add it to the melt.

The obtained molten metal has a reduced gas component, less inclusions, and improved fluidity. The solidified casting is a sound one with a homogenized metal structure.

The improving agent for metallurgy of the present invention is useful not only for improving a molten metal but also for improving a welding rod. For example,
When using a welding rod obtained by decarburizing the core wire with a treatment agent containing the treatment mixture and coating the core wire with a coating agent containing the treatment mixture, it is said that welding is difficult and sufficient strength cannot be obtained. It is possible to facilitate the welding of high alloys, castings, aluminum and dissimilar metals, and increase the strength.

Further, it is useful as a deoxidizing agent for steelmaking in the production of clean steel, and also has a function of improving the transverse rupture strength as an improving agent for powder metallurgy containing ceramics.

As described above, the improving agent for metallurgy of the present invention can improve various properties widely in the field of metallurgy and provide an improved product.

Next, the metallurgical composition and the improving agent of the present invention will be explained based on production examples and examples, but the present invention is not limited to these examples.

Production Example 1 80 parts by weight of ferric sulfide powder (particle size 150 to 200 mesh) and 20 parts by weight of apatite powder (particle size 150 to 200 mesh) were thoroughly mixed and heated at 400 ° C. for 4 hours. To obtain a treated powder.

Example 1 The following powders were mixed to prepare a metal melt improver of the present invention.

(Parts by Weight) Treatment Mixture of Production Example 1 35 Iron powder (sand iron) 32 Ferromanganese powder 7 Fluorite powder 5 Silicon carbide powder 10 Ferric oxide powder 11 100 In order to obtain a uniform particle size , 20 to 20
0 mesh was used.

0.3 kg of the obtained improving agent was sampled and filled in a steel can and sealed. A can containing this improving agent was put into 100 kg of molten cast iron (FC30), sampled 5 minutes later, and the residual oxygen content in the molten metal was measured by an infrared absorption method to be 31 ppm. The residual oxygen content of the hot water was similarly measured and found to be 82 pm.

Example 2 0.3 kg of the improver prepared in Example 1 was filled and sealed in a steel can, charged into 100 kg of cast iron (FC25) molten metal, and sampled after 10 minutes by sampling.

The cut surface of this sample was observed by a metallographic microscope (400 times) after corrosion with 3% nitric acid alcohol, and the homogeneity of the metal structure of cast iron was examined.

The results are shown in FIG. 1 as a sketch. For comparison, Motoyu was similarly examined. The results are shown in Figure 2.

The mechanical properties (tensile test, bending test, hardness, chill) of each sample were examined. The results are shown in Table 1. The test method is as follows.

(Tensile test) The tensile test was performed according to JIS Z2241. Test piece: Diameter 20 mm, temperature: 23 ° C.

(Hardness) The hardness was measured according to JIS Z 2243. For the sample, use the test piece used for the tensile test and measure it at the center position.

[0034]

[Table 1]

[0035]

According to the metallurgical improving agent of the present invention, deoxidation,
It is possible to remove inclusions, improve the soundness of the metal structure, and eventually improve the mechanical properties, and provide excellent products particularly in the fields of casting, welding, steelmaking, powder metallurgy and the like.

[Brief description of drawings]

1 is a sketch drawing of a micrograph of a metal structure of a casting of the present invention produced in Example 2. FIG.

FIG. 2 is a sketch drawing of a micrograph of a metal structure of a comparative casting obtained from the hot water prepared in Example 2.

Claims (20)

[Claims] 1. A metallurgical composition obtained by heat-treating a mixture of iron sulfide powder and silica stone powder. 2. Iron sulfide powder and silica stone powder in a weight ratio of 8 to 10.
6: 2-4 mixing at 450-650 ° C for 3-5
A metallurgical composition obtained by heat treatment for a period of time. 3. A metal melt improver comprising a treatment mixture obtained by heat treating a mixture of iron sulfide powder and silica stone powder. 4. The improver according to claim 3, wherein the metal is cast iron. 5. The improver according to claim 3, wherein the metal is aluminum. 6. The metal according to claim 3, which is an aluminum alloy.
The described improver. 7. The improver according to claim 3, wherein the metal is copper. 8. The improver according to claim 3, wherein the metal is a copper alloy. 9. The treatment mixture, carbon powder, silicon powder, aluminum powder, silicon oxide powder, aluminum oxide powder, ferric oxide powder, iron powder, ferromanganese powder,
The improving agent according to claim 3, 4, 5, 6, 7 or 8, which comprises at least one of fluorite powder and silicon carbide powder. 10. The treatment mixture 20 to 35% by weight, carbon powder 9 to 10% by weight, silicon powder 1.0 to 1.5% by weight, aluminum powder 0.4 to 0.5% by weight, silicon oxide powder 2.5 to 3.5% by weight and aluminum oxide powder. The improving agent according to claim 4, which comprises 0.7 to 1.0% by weight. 11. The improver according to claim 10, comprising ferric oxide powder as a bulking agent. 12. 15-45% by weight of the treatment mixture, 20 iron powders
5. The improvement according to claim 4, which comprises -40 wt%, ferromanganese powder 4-10 wt%, fluorspar powder 2-8 wt%, silicon carbide powder 5-15 wt% and ferric oxide powder 5-20 wt%. Agent. 13. Addition of 0.3 to 0.5 parts by weight of an improving agent containing 20 to 35% by weight of a treatment mixture obtained by heat-treating a mixture of iron sulfide powder and apatite powder to 100 parts by weight of molten metal. A method for producing a casting having a homogeneous metal structure with a low oxygen content and a low inclusion content. 14. A casting having a uniform oxygen content and a low content of inclusions, which is obtained by the method according to claim 13. 15. A modifier for a coated arc welding rod, which comprises a treatment mixture obtained by heat-treating a mixture of iron sulfide powder and silica stone powder. 16. A welding rod in which a core wire decarburized with a treatment agent containing the treatment mixture according to claim 15 is coated with a coating agent containing the treatment mixture. 17. A steelmaking improver comprising a treatment mixture obtained by heat treating a mixture of iron sulfide powder and silica stone powder. 18. A deoxidizing agent for steelmaking, comprising the treatment mixture according to claim 17. 19. A improver for powder metallurgy, comprising a treatment mixture obtained by heat-treating a mixture of iron sulfide powder and silica stone powder. 20. A bending strength improver for powder metallurgy, comprising the treatment mixture according to claim 19.