DE102018116813B3 - METHOD AND DEVICE FOR HOT FORMING METALLIC PREPARED PRODUCTS - Google Patents

Abstract

The invention relates to a method for hot working preheated elongated metallic precursors by a preheated precursor repeatedly passed through at least one forming tool and the precursor is then supplied to a surface reheating, such that before or after the forming a means for the controlled generation of heat is positioned Pre-product after a first forming process in the device, respectively, is passed through the device, the direction of movement of the precursor reversed and another forming process with, if necessary, subsequent surface heating in the other device is brought about.

Description

The invention is directed to a process for hot working preheated elongate metallic precursors.

By the term "hot working" the skilled person understands a cyclic or continuous reduction of the thickness, respectively the diameter, of precursors until they reach a definable final thickness. Hot rolling plants or hot forging facilities are ideal here.

It is generally known that in forging presses blocks, billet or bar stock is forged in round, square, or polygons. For this, the material must be heated in a separate oven to a predeterminable temperature (e.g., 500 - 1300 ° C). From a manipulator, the preheated material is taken and pushed gradually through the forging press, with the press moves after each step and reduces the thickness of the diameter of the precursor.

In this process, the precursor loses heat by radiation, which is released to the environment and the forging tool. Although forging transforming energy in the form of heat is reintroduced into the material, while still causing temperature losses at the surface.

This creates a situation in which the starting material is warmer at the core than at the surface. Even over the length of the material no uniform temperature distribution is achieved.

This temperature inhomogeneity leads to inhomogeneous particle sizes and to different precipitation states, whereby the required product properties are no longer achieved. Eventually, the material becomes too cold during the machining process and must be reheated in an oven.

The thinner and longer the material is or becomes, the more serious is the influence of the surface over which the heat is dissipated.

The DD 38 364 A1 discloses a method and apparatus for keeping constant the outlet temperature of the continuous heating material in induction heating systems.

According to the method, in a timing chain, taking into account the inlet temperature, the flow rate and the desired outlet temperature of the material to be heated, a desired value is formed and compared with an actual value resulting from the generator voltage lying on the inductor via a transformer in a control loop, wherein the control deviation the operating point a voltage stabilizer so that the predetermined outlet temperature is kept constant.

The DE 37 24 737 A1 a device for inductive heating of rods or the like for further processing (rolling mill, forge or the like) can be seen, the inductive heating is divided with constant feed in a zone for heating to the further processing temperature and a zone for keeping constant the processing temperature and the Rods are removed from the holding zone quickly.

The aim of the subject invention is to provide a method and apparatus for hot working elongated metallic precursors, with which the above-identified manufacturing problems are substantially avoidable.

In particular, a uniform structure over the entire cross section and the length of the metallic precursor should be brought about by temperature uniformity.

This object is achieved by a method for hot working preheated elongated metallic precursors by a preheated precursor repeatedly passed through at least one forming tool and the precursor is then supplied to a surface reheating, such that before or after the forming a means for the controlled generation of heat is positioned , the precursor is passed after a first forming process in the device, respectively by the device, the direction of movement of the precursor vice versa and another forming process with, if necessary, subsequent surface heating in a further device is brought about.

Advantageous developments of the method according to the invention can be found in the associated subclaims.

The object is also achieved by a device for hot working preheated elongated metallic precursors, consisting of at least one forming tool, manipulators for handling and guiding the precursors and at least one, seen in the direction of passage of the precursors, positioned next to the forming tool for the controlled generation of heat, said the precursors are repeatedly alternating in, respectively, by the forming tool and the respective device are feasible.

Advantageous developments of the device according to the invention can be found in the associated subject subclaims.

Advantageously, the preheated precursors are so long reversing in, respectively guided by the respective forming tool and the respective device until the precursor is brought to final thickness.

According to a further aspect of the invention, the method according to the invention can be optimally realized in a forming tool formed by a forging tool.

The term forging is understood by those skilled in the art to mean pressure forming of metals or alloys between two tools to locally change their cross-sectional shape. In detail, this is the distinction
Vorschmieden
Finish forging.

By Vorschmieden the starting material used is brought into a semi-finished product or workpiece as approximate as possible, albeit raw form.

In the case of ready forging, as a rule pre-forged materials, for example, are processed by a finishing process in such a way that the desired microstructural parameters are set.

The inventive method is preferably used in metallic materials, especially in materials with curing mechanisms, especially for materials with curing mechanisms in the temperature range of 350 to 1100 ° C, are used.

The method can advantageously be used for materials with a small temperature window for the hot forming of ΔT <400 ° C, in particular <200 ° C, respectively <100 ° C.

Devices for the controlled generation of surface heat can be formed for example by radiant heaters or the like.

However, it makes sense here that the respective device advantageously by an induction furnace, for example in half-shell design, is formed. However, closed induction furnaces are also conceivable.

Metallic precursors are produced from different metallic alloys for different applications. Here is often the problem that certain alloys either not or only very expensive hot forming, in particular warm forging, let.

The process of the invention should preferably be used for metallic precursors made of rod material. Here, all known alloys (e.g., copper, aluminum, titanium, steel, or the like) are first addressed.

In the process according to the invention, metallic precursors in the form of billets, blocks or bars of Ni alloys are preferably used, with a Ni content above 25 wt.%, In particular above 30 wt.%, Being present.

Alternatively, the above materials may also consist of Co alloys with Co contents above 25% by weight, especially above 30% by weight.

It can be advantageous if at least one of the alloying elements Mo, Nb, Ti, C, N, Al, W or Cr is added to the Ni or Co alloys.

• - Waspaloy
• - Alloy 80A
• - Alloy 718
• - Alloy 780

zum Einsatz gelangen.Specifically, however, the process of the invention should be based on nickel alloys, such as

• - Waspaloy
• - Alloy 80A
• - Alloy 718
• - Alloy 780

to be used.

Further Ni or Co alloys can be found in the annex.

If an induction furnace is to be used as a device for controlled heat generation, it makes sense here to resort to half-shell induction furnaces in the alloys mentioned above.

In such devices, the temperature measurement / control of the respective device may be e.g. outside the respective institution.

In so-called induction furnace forging, the preheated and (partially) formed precursor is forged into at least one open furnace (induction furnace). Here, the precursor is reheated on immersion in the oven exclusively on the surface. Since this is done at each forging, only a very small reheating is required and only near the surface. Induction heating is predestined for this purpose.

• - direkte Materialnachwärmung (keine Ofenraumnachwärmung),
• - höhere Prozessstabilität (Fertigungssicherheit),
• - höheres Materialausbringen durch mehr nutzbares Gefüge (geringeres Abschälen),
• - homogenes Gefüge über den gesamten Querschnitt und Länge,
• - Reduzierung der Anzahl von Rücklagen (mehr Ofenkapazität),
• - Reduzierung des Schmiedeaufwandes,
• - geringerer Energieverbrauch durch Materialdirektnachwärmung,
• - geringerer Temperaturverlust über die Länge des Vorproduktes,
• - Verkürzung der Gesamtschmiede- und Nachwärmzeit.

The method according to the invention or the device according to the invention has the following advantages:

• direct material reheating (no furnace room reheating),
• - higher process stability (manufacturing reliability),
• higher material output due to more usable structure (less peeling),
• homogeneous structure over the entire cross-section and length,
• - reduction of the number of reserves (more furnace capacity),
• - reduction of forging costs,
• - lower energy consumption due to direct material reheating,
• lower temperature loss over the length of the precursor,
• - Shortening of the total forging and reheating time.

• 1 Prinzipskizze einer erfindungsgemäßen Induktionsofenschmiedung;
• 2 Prinzipskizze einer erfindungsgemäßen alternativen Induktionsofenschmiedung;
• 3 Prinzipskizze eines geschlossenen Induktionsofens.
• 4 Prinzipskizze eines Halbschaleninduktionsofens;

The subject invention is illustrated by means of an embodiment in the drawing and will be described as follows. Show it:

• 1 Schematic diagram of an induction furnace forging according to the invention;
• 2 Schematic diagram of an alternative induction furnace forging according to the invention;
• 3 Schematic diagram of a closed induction furnace.
• 4 Schematic diagram of a half-shell induction furnace;

1 shows as a schematic diagram of a so-called induction furnace forging. As a starting material to a rod, for example. Alloy 718 , are used. Other precursors of alternative, aforementioned alloys are also conceivable. In principle, a forming tool is shown 1 in the form of a forging press, preheated preliminary product 2 in the form of bar stock and devices for the controlled generation of heat 3 in the form of induction furnaces. Only indicated are manipulators 4 for handling the precursor 2 in the area of the forming tool 1 , respectively the respective institution 3 , The arrows indicate a reversing movement of the precursor 2 indicated. Here it is not clear that the device 3 is formed by at least one mobile half-shell induction furnace, in addition to the forming tool 1 is arranged. By the facilities 3 Continuous inductive reheating takes place exclusively on the surface 5 of the starting material 2 during the forging. Since a continuous reheating takes place, the inductive method is ideal since this only the surfaces 5 heated. The kiln dimensioning can thus be kept low because of a reheating in the surface of approx. 20 up to 150 ° C can be assumed. This depends on the thickness / diameter and the length of the precursor.

This results in a uniform temperature profile over the entire cross section and the entire length of the starting material 2 ensured.

Only indicated is a so-called Vorwärmofen 6 , Here is the precursor 2 brought to a hot forming temperature over several hours. Depending on the alloy, preheating temperatures of 800 - 1,300 ° C can be used.

In the present example (Alloy 718 ), the precursor should be brought to a preheating temperature of 1000 ° C, wherein the entire cross section of the precursor 2 is warmed up.

On the way from the preheating furnace 6 into the area of the forming tool 1 loses the precursor by radiation to heat. A temperature loss of 60 ° C is assumed. This from Upper 7 and lower tool 8th existing forming tool 1 performs forgings while the input material 2 in the direction of the reheating device 3 through the manipulators 4 to be led. For an assumed total diameter of the precursor 2 from 450 mm it is in a first forging engraving to a diameter of 420 mm, over the total length of the precursor 2 seen, brought. During this forging phase, the precursor suffers another temperature loss ΔT of assumed 30 ° C at the surface 5 , Through the manipulators 4 becomes the precursor 2 in the facility 3 into forged. The trained as induction furnace device 3 offsets the ΔT loss so that the precursor 2 again has a surface temperature of 940 ° C for a reversing forging.

Due to the uniform temperature, it is possible to produce a semi-finished or a workpiece with little change in grain size over the cross-section and length less than 8th , or. 6 , or 4 Ideally 2 Having ASTM grain size differences. Thus, semifinished product can be produced which has a completely recrystallized structure up to the areas near the surface. 2 shows an alternative induction furnace forging according to the invention. Deviating from 1 are here next to the forming device 1 two facilities 3 for reheating the surface 5 of the precursor 2 given. Otherwise, the device is analogous to 1 built up. The precursor 2 is in the preheating furnace 6 brought to forming temperature and before the right device 3 in the facility 3 and then into the forming tool 1 guided. By reversing the manipulators 4 the precursor is in reducing its diameter / thickness and increasing length respectively in the facilities provided on both sides 3 into forged. Depending on the diameter / thickness reduction, the length of the precursor increases. The ΔT changes gradually with. The initial assumed ΔT of 30 ° C may be ΔT in the final stage of forging at 100-130 ° C. These temperature losses are predetermined by a control device that the respective device 3 depending on the forging progress accordingly.

As an alternative to a forging press, at least one hot rolling mill with upstream and downstream induction furnaces can also be used.

As stated above, there are different alloys for precursors 2 , which are difficult to hot-form, especially hot forging.

Some of these alloys are listed in Table 1 (Appendix) in general form:

3 shows a schematic diagram of a designed as an induction furnace device 3 for controlled generation of heat according to 1 , The device 3 is formed by a closed induction furnace. Only indicated are coils 9 , about which also only indicated, formed as a bar stock material 2 is passed. In the facility 3 finds the reheating of the surface 5 of the precursor 2 instead of compensating for the temperature loss ΔT. Not indicated, however, is covered by the scope of protection, that the temperature measurement / control of the respective device 3 outside the facility 3 he follows.

4 shows an alternative device 3 , formed by a U-shaped half-shell 10 , in whose cross-section coil elements 11 are provided. To the entire surface 5 of the precursor 2 It can be useful to pre-heat the product evenly 2 to put in small rotations.

LIST OF REFERENCE NUMBERS

1

forming tool

2

precursor

3

Facility

4

manipulator

5

surface

6

preheating

7

upper tool

8th

lower tool

9

Kitchen sink

10

half shell

11

coil element

Table 1 Alloy 601 Alloy 602 CA / MCA FM 602 Alloy 617 (B / OCC) FM 617 Dimensions% min. - max min. - max min. - max min. - max min. - max C 0.03-0.1 0.15-0.25 0.15-0.25 0.05-0.08 0.05-0.15 S -0,015 -0.01 -0,008 N Cr 21-25 24-26 24-26 21-23 20-24 Ni 58-63 59-66 59-66 45-58 50-61 Mn -1 -0.5 -0.5 -0.5 -1 Si -0.5 -0.5 -0.5 -0.3 -1 Mo 8-10 8-10 Ti -0.5 0.1-0.2 0.1-0.2 0.25-0.5 -0.6 Nb -0.6 Cu -0.5 -0.1 -0.1 -0.5 Fe -18 8-11 8-11 -1.5 -3 P -0.02 -0.02 -0.012 -0.03 al 1-1.7 1.8-2.4 1.8-2.4 0.8-1.3 0.8-1.5 mg Ca SE V -0.6 Zr 0.01-0.1 0.01-0.1 W -0.5 Co -1 11-13 10-15 Y 0.05-0.12 La B -0.006 0.001-0.005 Hf Ta Ce O pb sn Zn se Bi sb CD hg H ace Nb + Ta 3.2-3.8 Alloy 625 FM 625 Alloy 690 Alloy 699XA Alloy 718 Alloy 718 CTP FM 718 Dimensions% min. - max min. - max min. - max min. - max min. - max min. - max min. - max C -0.03 -0.1 -0.05 0.005 to 0.12 -0.08 -0.045 -0.08 S -0.01 -0,015 -0.01 -0,015 -0.01 N -0.05 Cr 21-23 20-23 27-31 26-30 17-21 17-21 17-21 Ni 58-71 58-71 58-66 62-72 50-55 50-55 50-55 Mn -0.5 -0.5 -0.5 -0.5 -0.35 -0.35 -0.3 Si -0.4 -0.5 -0.5 -0.5 -0.35 -0.35 -0.3 Mo 8-10 8-10 2.8 to 3.3 2.8 to 3.3 2.8 to 3.3 Ti -0.4 -0.4 -0.6 0.65 to 1.15 0.8 to 1.15 0.7-1.1 Nb 3 to 4.1 -0.5 4.75-5.5 Nb + Ta 4.8-5.5 Cu -0.5 -0.5 -0.5 -0.3 -0.23 -0.3 Fe -5 -5 7-11 -2.5 6-25 12-24 -24 P -0.01 -0.02 -0,015 -0.01 -0,015 al -0.4 -0.4 2-3 0.2-0.8 0.4-0.6 0.2-0.8 mg Ca SE V Zr -0.1 W Co -1 -1 -1 Y La B -0,008 -0.006 -0.006 -0.006 Hf Ta -0.05 Ce O pb -0.0005 -0.001 sn Zn se -0.0003 -0.0005 Bi -0.00003 -0.00005 sb CD hg H ace Nb + Ta 3.2-3.8 3.2-3.8 4.87 to 5.2 Alloy 780 Alloy 788 waspaloy Alloy C-263 Alloy 80A Alloy 81 N07001 2.4654 Dimensions% min. - max min. - max min. - max min. - max min. - max min. - max C -0.1 0.04-0.1 0.02-0.1 0.04-0.08 0.04-0.1 -0.08 S -0,015 -0.01 -0.03 -0.007 -0,015 -0.02 N -0.03 Cr 16-20 18-21 18-21 19-21 18-21 28-32 Ni 26-62 51-69 49.6 to 62.5 50-55 65-79 59-66 Mn -0.5 -1 -1 -0.6 -1 -0.7 Si -0.3 -0.5 -0.75 -0.4 -1 -0.7 Mo 43192 3,5-5 5.6-6.1 -0.5 Ti 0.1-1 1.8-2.7 2.75-3.25 1.9-2.4 1.8-2.7 1.5-2.1 Nb Cu -0.5 -0.2 -0.5 -0.2 -0.2 -0.25 Fe -10 8-15 -2 -0.7 -1.5 -1.5 P -0.03 -0.02 -0.03 -0,015 al 1-3 1-1.8 1.2-1.6 0.3-0.6 1-1.8 -1.2 mg -0.01 -1 Ca -0.01 SE V Zr -0.05 0.02-0.12 0.01-0.1 W Co 15-28 3-7 12-15 19-21 1-3 Y La B -0.02 -0,008 0.003-0.01 -0,005 -0.006 Hf Ta Ce O -0.02 pb -0,002 sn Zn se Bi sb CD hg H ace Nb + Ta 4-6 Alloy K-500 Alloy X-750 Alloy 31 Plus Alloy 28 Alloy 31 Alloy AC 66 N07750 2.4669 Dimensions% min. - max min. - max min. - max min. - max min. - max min. - max C -0.18 -0.08 -0.01 -0,015 -0,015 0.04-0.08 S -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 N 0.1-0.25 0.04-0.07 0.15-0.25 Cr 14-17 26-27 26-28 26-28 26-28 Ni 63-70 70 to 77.5 33.5 to 35 30-32 30-32 31-33 Mn -1.5 -1 1-4 -2 -2 -1 Si -0.5 -0.5 -0.1 -0.7 -0.3 -0.3 Mo 6-7 3-4 6-7 Ti 0.35 to 0.85 2.25 to 2.75 Nb 0.7-1.2 0.6-1 Cu 27-33 -0.5 0.5-1.5 1-1.4 1-1.4 Fe 0.5-2 5-9 22.5 to 33.5 32-40 29-37 37-42 P -0.02 -0.02 -0.02 -0.02 -0,015 al 2.3 to 3.15 0.4-1 -0.3 -0,025 mg Ca SE V Zr W Co -1 Y La B Hf Ta Ce 0.05-0.1 O pb -0.006 sn -0.006 Zn -0.02 se Bi sb CD hg H ace Nb + Ta 0.7-1.2 Alloy 333 Alloy 22 Alloy C-276 Alloy 2120 MoN Alloy 59 Alloy C-4 Dimensions% min. - max min. - max min. - max min. - max min. - max min. - max C 0.03-0.06 -0.01 -0.01 -0.01 -0.01 -0.009 S -0.01 -0.01 -0.01 -0.01 -0.01 N 0.02-0.15 Cr 24-26 20 to 22.5 15 to 16.5 20-23 22-24 14.5 to 17.5 Ni 44-47 50-63 51-63 58-58 57-63 58 - 75 Mn 1,2-2 -0.5 -1 -0.5 -0.5 -1 Si 0.8-1.2 -0.08 -0.08 -0.1 -0.1 -0.05 Mo 2.5-3.5 12.5 to 14.5 15-17 18.5 to 21 15 to 16.5 14-17 Ti 0.1-0.2 -0.7 Nb Cu -0.5 -0.5 -0.5 Fe 13-22 2-6 4-7 -1.5 -1.5 -3 P -0,025 -0.02 -0,015 -0,015 -0.02 al -0.4 -0.4 mg Ca SE V -0.35 -0.3 Zr W 2.5-3.5 2.5-3.5 3-4,5 -0.3 Co 2.5-3.5 -2.5 -2.5 -0.3 -0.3 -2 Y La B Hf Ta Ce O pb sn Zn se Bi sb CD hg H ace Nb + Ta Alloy 751 Alloy B-2 Alloy 25 Alloy 188 Dimensions% min. - max min. - max C -0.1 -0.01 -0.15 -0.15 S -0.01 -0.01 -0,015 -0,015 N Cr 14-17 0.4-1 19-21 20-24 Ni 70- 64-72 9-11 20-24 Mn -1 -1 1-2 to 1.25 Si -0.5 -0.08 -1 0.2-0.4 Mo 26-30 Ti 2 to 2.6 Nb 0.7-1.2 Cu -0.5 -0.5 Fe 5-9 1.6-2 -3 -3 P -0.02 -0,015 -0,015 al -1.5 -0.2 mg Ca SE V Zr W 14-16 13-16 Co -1 rest rest Y La 0.02-0.12 B to 0.01 Hf Ta Ce O pb sn Zn se Bi sb CD hg H ace Nb + Ta

Claims (16)

A process for the hot forming of preheated (6) elongated metallic precursors (2) by repeatedly passing a preheated precursor (2) through at least one forming tool (1) and then feeding the precursor (2) to surface reheating, such that before or after the forming tool (1) a device (3) for the controlled generation of heat is positioned, the Pre-product (2) after a first forming process in the device (3), or through the device (3) is passed, the direction of movement of the precursor (2) vice versa and another forming process with, if necessary, subsequent surface reheating in the further device (3) is brought about , Method according to Claim 1 , characterized in that on both sides of the forming tool (1) means (3) for the controlled generation of heat is positioned. Method according to Claim 1 or 2 , characterized in that the precursor (2) reversing in, respectively by the forming tool (1) and the respective device (3) is guided until it is brought to final thickness. Method according to one of Claims 1 to 3 , characterized in that the forming tool (1) is formed by a forging tool. Method according to one of Claims 1 to 4 , characterized in that the respective device (3) is formed by radiant heaters. Method according to one of Claims 1 to 4 , characterized in that the respective device (3) is formed by an induction furnace. Method according to one of Claims 1 to 6 , characterized in that the metallic precursors (2) by billets, blocks or rod material of Ni alloys with Ni contents above 25 wt .-%, in particular above 30 wt .-%, are formed. Method according to one of Claims 1 to 6 , characterized in that the metallic precursors (2) by billets, blocks or bar material of Co alloys with Co contents above 25 wt .-%, in particular above 30 wt .-%, are formed. Method according to one of Claims 7 or 8th , characterized in that the alloys of at least one of the alloying elements Mo, Nb, Ti, C, N, Al, W, Cr is added. Method according to one of Claims 1 to 9 , characterized in that the metallic precursors (2) are formed by sticks, blocks or rod material from Waspaloy, Alloy 80 A, Alloy 718 or Alloy 780. Device for the hot forming of preheated (6) elongated metallic precursors (2), consisting of at least one forming tool (1), manipulators (4) for handling and guiding the preheated (6) precursors (2) and at least one, in the direction of passage of the precursors (2 ), in addition to the forming tool (1) positioned means (3) for the controlled generation of heat, wherein the precursors (2) repeatedly in alternately, respectively by the forming tool and the at least one device (3) are feasible. Device after Claim 11 , characterized in that in addition to the forming tool (1) is provided in each case a device (3) for the controlled generation of heat. Device after Claim 11 or 12 , characterized in that the forming tool (1) is formed by a forging tool. Device according to one of Claims 11 to 13 , characterized in that the respective device (3) is formed by an induction furnace. Device after Claim 14 , characterized in that the respective induction furnace (3) is designed as a half-shell induction furnace. Device according to one of Claims 11 to 15 , characterized in that the temperature measurement / regulation of the respective device (3) takes place outside the respective device (3).

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