DD210525A3 - METHOD FOR PRODUCING FERRITIC HEATING WIRE - Google Patents

Abstract

The invention relates to the field of metallurgy and is applicable to the manufacture of ferritic heating conductor wire. The object of the invention is an economical production of high-quality heating conductor wire. The invention has for its object to simplify the manufacturing technology significantly and to make so that production disruptions largely restricted, lowered the Ziehsteinverschleiss and the material properties of the starting material are not affected. According to the invention, the starting material is first converted to an intermediate dimension of less than 7 mm and then coated while avoiding the application of a lubricant carrier with a homogeneous solid lubricant film, which does not contain the life of the Heizleiterwerkes impairing components. Subsequently, in a multi-stage drying course, the material is drawn up to the fine-drawing area, wherein in the first stage the degree of deformation is greater than 30%. Finally, while avoiding the usual cleaning and firing processes, the wire is drawn down to its final diameter in a fine draft.

Description

Method for producing ferritic heating conductor wire Field of application of the invention

The invention relates to the field of metallurgy and is applicable to the production of ferritic raw material heating conductor wire,

Characteristic of the known technical solutions.

When pulling wire, it is necessary that an immediate metallic contact between wire and die under the loads of the forming process is prevented · For this purpose, lubricant systems are used, which must be applied to the wire before forming · When forming wire from high-alloy materials, for example In the case of ferritic heating conductor material, the quality of the lubrication systems is particularly stringent. In such cases, the lubrication system always consists of a carrier layer produced on the wire surface and a lubricant applied subsequently. The carrier layer is preferably mixed with lime / common salt in several partial stages or by oxalating or boraxing. Ferritic heating conductor wire coated with this lubricant system is then pulled in a multi-stage drying cycle to the fine draw area. After the drying cycle, the heating conductor wire is subjected to a cleaning and an annealing treatment and then formed in a wet drawing machine filled with high-quality drawing oil down to its final dimension.

Sin disadvantage of this method is that the application of the carrier layer requires a not insignificant technological and material expense. In addition come the

Expenses for Removing the Remains of the Tragerschicht before the Feinzug · Another disadvantage of this method is that despite the performed before the Teinzug annealing and the use of high quality drawing oil, the wear of the peeling machine in the diamond dies is relatively high, thus It is also unsatisfactory that ferritic heat conductor wire formed according to the process does not meet all quality expectations, in particular with regard to its service life.

Object of the invention

The object of the invention is to create conditions for an economical production of high-quality ferritic hot conductor wire.

Explanation, the essence of the invention

The invention has for its object to simplify the technology of manufacturing ferritic heating conductor significantly and to make so that production disturbances largely limited, the die wear lowered and the material properties of the starting material during processing are not adversely affected.

This object is achieved according to the invention with a method in which the starting material initially to an intermediate dimension of less than 7 Ma diameter, preferably of about 2 mm, reshaped and then coated while avoiding the application of a lubricant carrier with a homogeneous solid lubricant film, the no Life of the Heizleiterwerkstoffs affecting constituents, such as alkali metals, halogen salts, carbonates, borates, silicates and polyphosphates. According to further features of the invention, this wire is subsequently drawn in a multi-stage drying train up to the Peinzugbereich, the first

Drawing stage is carried out with a degree of deformation of greater than 30 % for solid impregation of the plague lubricant on the wire. In addition, the invention provides that the wire is finally fed while avoiding the usual cleaning and annealing a Peinzug for forming to its final diameter.

As part of the conversion of the starting material to the intermediate dimension, a surface treatment can be carried out to eliminate contamination and surface defects. It is advantageous if'bei. the forming worked on the intermediate dimension lubricant carrier-free and used as a lubricant calcium stearate with increased oxide content, which is contained in an organic solvent. It is expedient if the wire formed on the intermediate dimension is subjected to an annealing and a molten salt treatment before being coated with the lubricant film. The wire can be treated with a residual residual film of residual pestle or applied with a stick-on homogenous pestle film applied after drying. The wire is suitably passed through a liquid lubricant consisting of calcium stearate with an increased proportion of oxide in an organic solvent to apply this pestle lubricant film After the application, this lubricant film is dried. According to the invention, at least some of the stages can also be carried out as a 2-roll train. The multi-stage Tension is performed while avoiding intermediate anneals. The wire is expediently shaped in the multi-stage drying cycle by means of pressure nozzles ,

A significant advantage of the method according to the invention is the elimination of a number of common process stages. For example, the costly application of a carrier layer for the lubricant is completely eliminated. Furthermore, the cleaning and annealing of the weir wire after the multi-stage drying cycle is no longer necessary.

In accordance with the present invention, disadvantageous effects on the service life of the heating conductor wire, as resulting from the carrier layers commonly used, are eliminated. It should also be emphasized that the invention achieves unusually high overall deformation ratios without intermediate annealing. ¹ In addition, the conditions for working at higher drawing speeds are created. It is surprising that a much lower Ziehsteinverschleiß occurs, whereby the life of the diamond drawing dies used in Peinzug considerably, that is increased by about 50% _o . Overall, the conditions are created with the invention to be able to produce ferritic heating conductor in excellent quality and at the lowest cost.

embodiment

Steel brand ferritic heat conductor material 15 CrAlI5.5 in the form of wire rod with a diameter of approx. 8 mm is drawn with conventional technology to an intermediate dimension of 2 mm diameter, but with no lubricant carrier. As part of this forming a surface processing in the form of a peeling process to achieve a smooth and surface defects and impurities free wire surface is performed. After forming to the intermediate dimension, the wire is freed of chemical contaminants and lubricant residues and subjected to annealing and molten salt treatment. On the thus treated wire, a lubricant is applied directly, ie, avoiding the application of a lubricant carrier layer, which consists of calcium stearate with increased oxide content in trichlorethylene. The trichlorethylene contains 6 percent by weight of calcium stearate. The lubricant film formed on the wire is subsequently dried. This results in a homogeneous Pestschmierstoffilm said calcium stearate, which is free from the life of the Heiζleitermaterials impairing components. With this solid lubricant film, the wire is subsequently

Gend by means of pressure nozzles multistage dry sucked. The pull sequence is 2.0 / 105 / 1.30 / 1.12 / 1.00 / 0.89 / 0.80. The overall degree of deformation is 84 %, wherein in the first drawing stage, a relatively high degree of deformation is realized, namely 40%. The i with a jewel erstoff-prone residual film 0.80 mm thick wire is subsequently up to its final diameter of 0.25 mm supplied directly to a wet drawing machine for fine wire drawing. The cleaning and annealing processes which are usually required before the fine draft or in the case of an intermediate dimension in the narrow draw area are not carried out.

Claims (2)

-ρ.ϊ -.- invention demanding ο A process for the production of heating conductor wire of ferritic starting material characterized gekenn ^ cl - * '<unet in that the starting material initially in a conventional manner to an intermediate dimension of less than 7 mm in diameter, preferably about 2 ram, reshaped and then avoiding Applying a lubricant carrier is coated with a homogeneous Pestschmierstoffilm that does not affect the life of the Heizleiterwerkstoffs affecting ingredients such as alkali metals, halogen salts, carbonates, borates, silicates and polyphosphates, and that this wire is subsequently drawn in a multi-stage drying train to the Peinzugbereich, Yi / obei the first drawing stage is carried out with a degree of deformation of greater than 30 % for solid impregation of the Pestschmierstoffs on the wire, and that finally the wire is fed to avoid forming the usual cleaning and annealing processes Teinzug for forming to its final diameter. 2o method according to item 1, characterized in that as part of the transformation of the starting material to the intermediate dimension, a surface treatment for the removal of. Impurities and surface defects ", 3o method according to item 1, characterized in that the conversion to the intermediate dimension lubricant is carried out carrier-free » 4 "method according to item 1, characterized in that in the reshaping dimensioning as a lubricant Galciumstearat.mit increased oxide content in an organic solvent is used _o -τ 5. The method according to item 1, characterized in that the rag formed on the zv dimension is subjected to annealing and molten salt pretreatment with the lubricant film before coating. Method according to item 1, characterized in that the wire is affixed to the fine draw with a residual solid residual film or is supplied with a firmly adhering, homogeneous solid lubricant film applied after the drying cycle. 7. The method according to item 6, characterized in that the wire for applying the solid lubricant film is passed through a liquid lubricant which consists of calcium oxide with increased oxide content in an organic solvent, and is subsequently dried. 8 »Method according to item 1, characterized in that at least some of the stages are carried out as a dry train in a multi-stage fine draw · 9 ^,! Method according to item 1, characterized in that a multi-stage fine draft is carried out while avoiding intermediate anneals. 10 · Method according to item 1, characterized in that the wire in the multistage drying train is shaped by means of pressure nozzles.