JP3058376B2 - Precipitating and / or stress-sensitive and / or segregating copper alloy strip casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a process for strip casting a precipitation-resistant and / or stress-sensitive and / or segregating copper alloy.

[0002]

BACKGROUND OF THE INVENTION As is well known, a series of copper alloys cannot be produced at all or economically by conventional block casting methods, followed by cold working including hot working and intermediate tempering. Either (a) difficulties in hot working based on grain boundary precipitation, segregation or other non-uniformities, or (b) because the cast plate after normal cooling is sensitive to stress It is.

[0003]

Although some of the above problems are alleviated by conventional conventional casting of strips about 10-20 mm thick, the above disadvantages (especially segregation phenomena) are not sufficient. Cannot be suppressed. The thicker strips thus require a homogenous tempering, e.g. at a high temperature, before the subsequent actual working, immediately after casting or a slight cold working.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention relates to a method for controlling the formation of precipitates in copper alloys, which completely suppresses the formation of precipitates or forms an extremely fine dispersion without any post-treatment and is sensitive to stress. For copper alloys, the formation of intrinsic stress is prevented, and in the case of alloys that are easy to segregate, the precipitation and / or stress sensitivity and the form of suppressing segregation phenomena to the extent that the alloy can be directly cold-worked Another object is to provide a method for casting a segregable copper alloy.

[0005]

This object is achieved according to the invention by casting a strip having a thickness D of 8 mm or less, while keeping the solidification rate X = 0.2-8 mm / s. . In this case, the solidification rate is understood as the average rate at which the crystal front travels in the liquid phase.

[0006]

By observing the above conditions, in some cases, after removing the cast surface layer mechanically, an appropriate microstructure can be immediately obtained, in which machining such as cutting and cold rolling can be immediately performed. At the same time, the thinness of the casting also reduces the stress on the product reasonably.

[0007] DE-PS 3,803,194 describes a method of casting a phosphor bronze strip which proposes a high cooling rate in order to avoid segregation .
To avoid the disadvantages of copper alloys with high application sensitivity and segregation, it has not been shown that the cooling rate from the melting point to the final temperature of the casting process is not metallurgically important . Appropriate combination of solidification front speed and local temperature gradient during hot water solidification appears to be important. The definition of the cooling rate of the liquid / solid mixture also does not correctly explain the combination and its retention. However, casting method according to the present invention <br/> provides a working manner consistent with the purpose.

By controlling the rate of solidification and the local temperature gradient by the casting method of the present invention, the distribution equilibrium of the solidification front is configured so that a particular solidification process is properly suppressed and another solidification process is facilitated. it can. Thus, for example, in the peritectic solidification process (e.g. in copper-iron or copper-tin systems, the undesired primary precipitation of iron (C
uFe) or undesired strong segregation (CuSn
) Can be modified to shift the solidification process to a eutectic state and eliminate undesirable results.

[0009] The above-mentioned items recognized when the casting method according to the present invention is applied are described in the latest research results (for example, D, HS
tJohn, Acta metall material, 3
8 (1990), 631-636).

In the method according to the invention, the necessary setting of the solidification rate is made by detecting the appropriate thickness of the casting. In this case, the use of a material with higher thermal conductivity allows the casting of thicker strips in the upper thickness range according to the invention, while at lower thermal conductivity it is better to work at the lower limit of the strip thickness. preferable. Another adjustment parameter is the cooling action, i.e., watering rate and casting speed.

Medium thermal conductivity (10-80 W / mK)
It is preferable to cast a strip having a thickness in the range of 1 to 5 mm. Particularly in the case of a precipitation-precipitating and segregating alloy, it is preferable to adhere to a solidification speed X of 6 to 8 mm / s. High solidification rates are preferably achieved by pouring hot water onto a strongly cooled circulating metal belt.

In this case, the hot water is poured into the cooling belt stretched between the 9 o'clock position and the 12 o'clock position of the direction changing roll or between the two transfer rolls.

On the basis of the casting method according to the invention, it is possible, in particular, to treat a group of precipitated and / or stress-sensitive or segregated copper alloys.

A copper-iron-zinc-phosphorus alloy having the following composition: iron 1.8-2.6%, zinc 0.05-0.2%, phosphorus 0.1%.
015-0.15%. The balance is 0.5% or less of additives of copper, ordinary impurities and one or more elements selected from the group consisting of titanium, zirconium, magnesium and tin.

A copper-iron-phosphorus alloy having the following composition: iron 0.05
-1.5%, phosphorus 0.01-0.45%. The rest is copper,
One selected from the group consisting of ordinary impurities and magnesium, titanium, zirconium, beryllium, tin
0.4% or less additive of one or more elements.

A copper-chromium alloy having the following composition: chromium 0.3
-1.2%. The balance is copper, normal impurities and additives of up to 0.5% of one or more elements selected from the group consisting of zirconium, titanium, iron and silicon.

A copper-chromium-titanium-silicon alloy having the following composition: chromium 0.1-0.5%, titanium 0.01-0.
5%, silicon 0.01-0.25%. The balance is up to 0.4% of additives of copper, common impurities and one or more elements selected from the group consisting of zinc, iron and nickel.

A copper-zirconium alloy having the following composition: 0.02-0.3% zirconium. The balance is copper, normal impurities and additives of up to 0.4% of one or more elements selected from the group consisting of iron, chromium, tin and phosphorus.

A copper-nickel-tin alloy having the following composition: nickel 5.0-15.5%, tin 2-8.5%. The rest is
Selected from the group consisting of copper, common impurities, up to 1.5% manganese, iron and zinc, up to 0.5% chromium, titanium, magnesium and zirconium and up to 0.3% phosphorus. One or more additives.

The following composition of copper-nickel-tin-titanium-
Chromium alloy: nickel 0.2-3.0%, tin 0.2-3.0%, titanium 0.1-1.5%, chromium 0.5-1
%. The balance is less than 1% of additives of one or more elements selected from the group consisting of copper, common impurities and iron and zinc.

A copper-nickel-tin-aluminum alloy having the following composition: nickel 4-10%, tin 1-3%, aluminum 1-3%. The balance is copper, normal impurities and 1%
Consisting of the following manganese, iron, zinc and silicon and up to 0.5% of zirconium, chromium and titanium and up to 0.3% of an additive of one or more elements selected from the group consisting of magnesium and phosphorus: .

A copper-nickel-silicon alloy of the above composition:
Nickel 1-4%, silicon 0.2-0.8%. The balance consists of copper, normal impurities and up to 1.5% of iron, manganese, zinc and tin and up to 0.8% of chromium, titanium and magnesium and up to 0.3% of zirconium and phosphorus. And an additive of one or more elements selected from the group consisting of:

Copper-tin-phosphorus alloy having the following composition: tin 1-11%, phosphorus 0.01-0.35%. The balance consists of copper, normal impurities and up to 6% of zinc and up to 2.5% of iron, manganese and nickel and up to 0.5% of chromium, titanium and magnesium and up to 0.2% of zirconium. And possible additives of one or more elements selected from the group consisting of:

Copper-zinc alloy having the following composition: zinc 2-5%.
The balance is copper, normal impurities, up to 4% lead, up to 2% iron and tin, up to 3% nickel, up to 2% silicon and up to 0.5% chromium, titanium and magnesium and 0%. 0.3% or less of zirconium and 0.2% or less of phosphorus with possible additives of one or more elements selected from the group consisting of:

[0025]

The present invention will be described in detail with reference to the following examples. FIG. 1 shows a casting apparatus for continuously producing a metal strip 1 having a target dimension of a thickness D. The hot metal 3 in the distributor 2 is supplied from the upper part through a channel 4 to an endless metal cooling belt 5 circulating through direction changing rolls 6 and 7. Metal belt 5, Ru is strongly cooled from the lower surface. Due to the intense cooling, rapid heat dissipation is achieved, thus achieving a high solidification rate in combination with other operating parameters.

[0026]

[Embodiment 1] The alloy CuNi8Al was produced by the above-described apparatus.
Thickness D = 7 mm and width 20 consisting of 1.6 Sn1.7
0 mm strip 1 was cast at a casting speed of 10 m / min. Cast in. In this case, the solidification rate was X = 2.2 mm / s. After milling a 0.5 mm thickness from the upper and lower surfaces of the cast strip, respectively, the material could be cold rolled by 90% without edge cracks and rolling defects. Dimensions 820 × 130 × about 5,000
During the normal continuous casting of a hot-rolled plate having a thickness of 1 mm, subsequent hot rolling could not be carried out, and even after homogenization, a structure in which extremely strong edge cracks extending over 1/3 of the width of the plate were generated by hot rolling.

FIG. 2 shows the cast structure of the strip manufactured according to the present invention at a magnification of 50 times. Although a fine dendrite structure was observed, the distance between the branches was only 1/5 of the numerical value in the case of a normal cast product, and no precipitate was recognized at the grain boundary.

[0028]

Embodiment 2 Thickness 6.5 made of CuNi6Sn6 alloy
mm, a strip 1 having a width of 150 mm was cast at a casting speed of 12 m /
min. Cast in. In this case, the solidification rate is X = 2.1
mm / s. After cutting a thickness of 0.5 mm from the upper and lower surfaces of the casting strip with a frying machine,
Without edge cracks or other rolling defects
The material could be cold rolled by 87%.

FIG. 3 shows the structure of the cast strip at 1.00.
It is shown enlarged to 0 times. Slight precipitates were observed,
Workability was not impaired.

On the other hand, when a strip or plate is cast by an ordinary continuous casting method, the structure shown in FIG.
0) was obtained. The average tin content of these dark banded areas is about 5% by weight higher than the surroundings. That is, this is segregation solidified in eutectic form. The workability of this structure is very limited, both hot and cold.

[0031]

The copper alloy strip casting method according to the present invention is configured as described above. Therefore, when precipitates are formed, the formation of the precipitates is suppressed, or an extremely fine dispersed form is performed without performing post-treatment.When sensitive to stress, formation of an intrinsic stress is prevented, and segregation is likely to occur. Therefore, the segregation phenomenon can be suppressed to such an extent that the alloy can be directly cold-worked.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a casting apparatus for continuously producing a metal strip having a target dimension of a thickness D.

FIG. 2 is an enlarged view of a cast structure of a strip obtained by the present invention magnified 50 times.

FIG. 3 is an enlarged view magnified 1,000 times.

FIG. 4 is an enlarged view in which the cast structure of a strip obtained by a normal continuous casting method is magnified 1,000 times.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Strip 2 Distributor 3 Metal hot water 4 Channel 5 Cooling belt 6 Direction change roll 7 Direction change roll

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Jog Kehesse, Germany D-7958 Lowheim Ahornweg 48 (72) Inventor Andras Bogel, Germany D-7913 Senden Gustavlasse 16 (72) Inventor Monica Breu, Germany , D-7900 Ulm Winstruth 69 (56) References JP-A-64-17828 (JP, A) JP-A-62-220251 (JP, A) JP-A-3-248743 (JP, A) JP-A 63 −195253 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C22C 1/02 B22D 11/00-11/20

Claims (16)

(57) [Claims] 1. A casting method for producing a strip 1 from a precipitation and / or stress sensitive and / or segregating copper alloy bath 3 in which a solidification rate X = 0.2-8 mm / s.
And strongly adhere to the strip 1 with a thickness D of 8 mm or less.
A casting method characterized by casting by pouring hot water 3 onto a circulating metal belt 5 to be cooled . 2. A strip 1 having a thickness range D = 1-5 mm.
The casting method according to claim 1, wherein the casting is performed. 3. The casting method according to claim 1, wherein the solidification speed X = 6-8 mm / s is observed. 4. The direction change roll 6 at 9 o'clock and 12:00 o'clock
The hot water 3 is placed on the metal belt 5 in the range between
The casting method according to any one of claims 1 to 3 , wherein: 5. The direction changing roll 6 and the direction changing roll 7
It is characterized by charging on the metal belt 5 and hot water 3 between
The casting method according to claim 4, wherein 6. The composition having the following composition : 1.8-2.6% iron.
0.05-0.2% zinc and 0.015-0.15% phosphorus
Containing copper and titanium as a normal impurity,
Group consisting of zirconium, magnesium and tin
0.5% or less of one or more elements selected from
And a strip made of a copper-iron-zinc-phosphorus alloy
The casting method according to any one of claims 1 to 5, wherein the casting is cast. 7. The following composition : iron 0.05-1.5%
And 0.01-0.45% of phosphorus, the balance being copper,
Magnesium, titanium, zirconium as common impurities
Selected from the group consisting of aluminum, beryllium and tin
With up to 0.4% of additives of one or more elements
Casting strip 1 made of copper-iron-phosphorus alloy
The casting method according to claim 1, wherein: 8. The composition having the following composition : chromium 0.3-1.2.
%, The balance being copper and zirconia as a normal impurity.
Select from the group consisting of aluminum, titanium, iron and silicon
0.5% or less of one or more additives
Cast strip 1 of copper-chromium alloy
The casting method according to claim 1 , wherein: 9. The composition having the following composition : 0.1-0.
5%, titanium 0.01-0.5% and silicon 0.01-
0.25%, the balance being copper and normal impurities
Selected from the group consisting of zinc, iron and nickel
With up to 0.4% of additives of one or more elements
Strip consisting of copper-chromium-titanium-silicon alloy
The casting method according to any one of claims 1 to 5, wherein 1 is cast. 10. The following composition : zirconium 0.0
2-0.3%, the balance being copper and normal impurities
Selected from the group consisting of iron, chromium, tin, and phosphorus
Copper comprising one or more additives up to 0.4%
Casting a strip 1 of zirconium alloy;
The casting method according to any one of claims 1 to 5, wherein 11. The composition having the following composition : nickel 5.0-1
5.5% and tin 2-8.5%, the balance being copper
And 1.5% or less of manganese, iron and
And zinc with 0.5% or less of chromium, titanium, and magnesium
And zirconium and up to 0.3% phosphorus
Adding one or more elements selected from the group consisting of
Strip consisting of a copper-nickel-tin alloy
The casting method according to any one of claims 1 to 5, wherein the casting is cast. 12. The composition having the following composition : nickel 0.2-
0.3%, tin 0.2-3.0%, titanium 0.1-
1.5% and 0.5-1% of chromium, the balance being copper
And a group consisting of iron and zinc as common impurities
1% or less additive of one or more elements selected from
Copper-nickel-tin-titanium-chromium alloy comprising
Casting a strip 1 comprising:
The casting method according to any one of claims 1 to 5 . 13. The following composition : nickel 4-10%
And 1-3% of tin and 1-3% of aluminum,
The balance is copper and less than 1% manganese as normal impurities
, Iron, zinc and silicon, and up to 0.5% zircon
With less than 0.3% of magnesium, chromium and titanium
One selected from the group consisting of calcium and phosphorus
Or a copper-nickel alloy comprising an additive of a plurality of elements
'S - casting the strip 1 made of an aluminum alloy
The casting method according to claim 1, wherein: 14. The following composition : nickel 1-4%
And silicon 0.2-0.8%, the balance being copper
And 1.5% or less of iron and manganese as ordinary impurities,
Zinc and tin and up to 0.8% chromium, titanium,
And magnesium with less than 0.3% zirconium and
One or more selected from the group consisting of
Copper-nickel-silicon alloy comprising additives of the elements
Casting a strip 1 consisting of
Item 6. The casting method according to any one of Items 1 to 5 . 15. The following composition : tin 1-11%;
0.01-0.35% phosphorus, the balance being copper and
6% or less zinc as usual impurities and 2.5% or less
With iron, manganese and nickel
, Titanium and magnesium and up to 0.2% of jill
One or more selected from the group consisting of conium
A copper-tin alloy comprising a number of possible additives
2. A strip 1 is cast.
5. The casting method according to 5 . 16. A composition having the following composition, that is, containing 2-5% of zinc.
And the balance is copper and less than 4% lead as a normal impurity
And up to 2% iron and tin and up to 3% nickel
And less than 2% silicon and less than 0.5% chromium
Tan and magnesium with 0.3% or less zirconium
And a group consisting of less than 0.2% phosphorus
Copper-zinc comprising one or more additive elements
Characterized by casting a strip 1 made of an alloy
The casting method according to claim 1 .