EP0601024A1

EP0601024A1 - Process for producing a ski edge.

Info

Publication number: EP0601024A1
Application number: EP92918428A
Authority: EP
Inventors: Hans-Toni Junius
Original assignee: Cd Waelzholz Produktions-Gesellschaft Mbh; C D WAELZHOLZ PRODUKTIONS GES
Current assignee: Cd Waelzholz Produktions-Gesellschaft Mbh; C D WAELZHOLZ PRODUKTIONS GES
Priority date: 1991-08-28
Filing date: 1992-08-26
Publication date: 1994-06-15
Anticipated expiration: 2012-08-26
Also published as: JPH07500739A; JP3283513B2; EP0601024B1; DE4218099A1; DE4218099C2; US5451276A; WO1993004742A1; ATE119052T1

Abstract

PCT No. PCT/EP92/01958 Sec. 371 Date May 10, 1994 Sec. 102(e) Date May 10, 1994 PCT Filed Aug. 26, 1992 PCT Pub. No. WO93/04742 PCT Pub. Date Mar. 18, 1993.A process is disclosed for producing a ski edge made of quenched and subsequently tempered steel having a head (2) that comprises the running surface and a flank (4) that projects into the body of the ski. The profiled edge (1) is at first rolled, then quenched and subsequently tempered over its whole cross-section. Afterwards, the flank (4) is partially tempered and provided in a separate operation with punched out openings. In order to obtain with this process a totally straight ski edge, the deviation in Rockwell hardness, seen in the direction of the cross-section and length of the profiled edge is set at less than 2 DEG HRC during quenching and subsequent tempering of the whole profiled edge. The warming-up temperature and duration during partial warming-up of the edge are the same over the whole length of the profile edge and the profiled edge is subjected to a constant bending strain before being punched.

Description

5

10 Processes for making a

Ski edge

Is formed of a ski edge of heat-treated steel, which has a surface having the Lauf¬ head and projecting into the body of the ski edge which is thinner than the head and a ausge¬ along its length - The invention relates to a process for the preparation of ^~ A plurality of punched recesses and / or openings is provided,

20 with the successive process steps listed below:

a) rolling or pulling the edge profile; b) tempering the entire edge profile by heat up - ^• - to the hardening temperature and then

Tempering; c) partial heating of the flank to a temperature greater than the tempering temperature with simultaneous cooling of the head; 0 d) punching the recesses and / or openings in the flank.

A method of the type mentioned is known from DE-OS 22 04 270. Ski edges produced according to this method have the advantage on the one hand that the 5th

Head is very hard over the entire cross-section by forming a martensitic structure, so that one long life of the ski edge without resharpening results. On the other hand, the flank is returned to an essentially pearlitic structure by the partial heating, so that this flank is relatively soft and ductile and can accordingly be machined by punching with little tool wear.

Although the previously known method offers the advantages discussed above, it has not been possible to introduce it in practice. This is essentially due to the fact that the ski edge produced in this way does not run in a straight line, but is curved differently in the main plane of extension. Attempts to avoid these inevitable curvatures - also called saber deviations or to reverse them by subsequent bending deformation - have failed in the past due to the fact that the radii of curvature occurring differ greatly over the length of the edge profile, so that it is practically impossible to the bending device to set the correct bending deformation in each case.

It is an object of the invention to design the method of the type mentioned at the outset in such a way that the ski edge produced thereafter runs in a completely straight line.

To achieve this object, the invention proposes, based on the method of the type mentioned, that when the entire edge profile is tempered, the deviation in the Rockwell hardness across the cross section and the length of the edge profile is set to less than 2 ° HRC that the heating temperature and the heating time during the partial heating of the flank are kept constant over the length of the edge profile and that the edge profile after the partial heating and before punching is subjected to a constant bending deformation, in which the flank is subjected to a constant amount is stretched. The invention is based on the knowledge that the unavoidable saber deviations are essentially the result of volume changes which occur when the martensitic structure changes to a ferritic / pearlitic structure. In the transition from a martensitic to a ferritic / pearlitic structure of a carbon steel, there is a volume contraction

10 tion, which in the present case - since the post-treatment on the edge profile only takes place on one side in the area of the flank - inevitably leads to strong saber formation. If an appropriate heat treatment is used to ensure that, on the one hand,

₁₅ th edge profile, the deviations in the Rockwell hardness - ie in the formation of martensite - are small over the cross section and the length of the edge profile, and on the other hand the heating temperature and the heating duration, ie the pearlite formation - in the partial

_"0 len heating of the flank along the length of Kantenprofi¬ les are largely constant, so in a subsequent bending deformation by uniform stretching of the edge of the profiled edge is obtained over the length of the profiled edge a uniform Säbelabwei¬ Chung,

"- can be easily undone.

The very uniform formation of a martensite in the edge profile before the partial heating required according to the invention can be achieved, for example, by

" ₀ tempering of the entire edge profile, a multi-stage continuous tempering is carried out, in which the edge profile is first cooled abruptly in a continuous metal bath to a temperature just above the martensite starting temperature (Ms), followed by a _{g5 structural} transformation of the austenitic formed during the cooling of the abraded surface Structure in the artensitic structure slow cooling is carried out under an air shower and finally a tempering treatment is carried out under protective gas. In contrast to the oil quenching conventionally used, the multistage remuneration explained leads to a very uniform martensitic structure, which is largely free of internal stresses. The metal bath quenching and tempering under protective gas have the effect that oxidation phenomena on the profile surfaces are avoided. The latter is important for the subsequent uniform heating of the flank of the profile, which would be hindered by oxidation layers.

The above-mentioned cooling of the rug takes place expediently in a lead bismuth continuous bath with a constant temperature of in particular 350 ° C.

A particularly good quality ski edge, which can be stamped with low tool wear, results if the entire edge profile is tempered to a Rockwell hardness of 50 ° -60 ° HRC and the hardness of the flank is reduced to 30 ° -40 ° HRC by partial heating becomes,

An embodiment of the invention is explained below with reference to the drawings. Show it:

1: a cross section through a punched edge profile in a first embodiment;

FIG. 2: a top view of FIG. 1;

3: a cross section through a stamped edge profile in a second embodiment;

FIG. 4: a top view of FIG. 3;

Fig. 5: schematically the process according to the invention in its sequence; 6: schematically, the additional continuous starting device transverse to the direction of passage.

1 to 4, the edge profile is designated in its entirety by reference number 1. It consists of a head 2, which has the tread 3 and a flank 4, which is thinner than the head 2 and serves to anchor the edge profile 1 in the body of the ski.

As can be seen from FIGS. 2 and 4, the flank 4 is provided with punched recesses 5 (FIG. 2) or openings 6 (FIG. 4) which, when the edge profile 1 is fastened in the body of the ski, for better toothing and anchoring serve. In a departure from the exemplary embodiments shown, the recesses 5 and the openings 6 can also have a different shape.

The entire edge profile 1 consists of a hardenable steel, which is hardened by the method according to the invention in the area of the head 2 over its entire volume to a high hardness, for example a Rockwell hardness of 50 ° -60 ° HRC, while the flank 4 is reduced to, for example, 30 ° - 40 ° HRC by additional partial tempering.

The device for carrying out the method according to the invention shown in FIGS. 5 and 6 consists of a profile rolling mill 7 or a corresponding profile drawing system in which the continuous edge profile 1 receives the correct profile shape. The edge profile 1 then passes through a tempering system 8, in which the edge profile 1 is tempered uniformly over its entire cross section by heating to the supercritical temperature and then quenching and tempering, to a relatively high degree Hardness that corresponds to the final hardness of the head 2. Quenching in the tempering system 8 takes place in a continuous metal bath which contains a liquid lead-bismuth melt of constant temperature, preferably approximately 350 ° C. This temperature is just above the martensite start temperature (Ms). During the abrupt cooling process, an essentially austenitic structure is formed in the edge profile 4. The edge profile is then slowly cooled under an air shower, the austenitic structure previously formed in the Schroff cooling process being converted into a largely homogeneous martensitic structure. Then the edge profile 1 is tempered under protective gas to a relatively low tempering temperature in order to set the desired material properties exactly. With the multi-stage tempering explained above, the hardness is largely uniform over the cross-section and over the length of the edge profile 1. The deviations in the Rockwell hardness over the cross-section and the length of the edge profile 1 are at most 2 ° HRC.

Thereafter, the edge profile 1, which is uniformly hardened over its entire volume, passes through a continuous system 9 for the additional partial tempering of the flank 4. The amount of heat introduced in this process is constantly regulated in order to obtain a uniform bend over the length of the edge profile 1. Only then is it possible to precisely align the material after partial tempering.

The continuous system shown in FIG. 6 for the additional partial starting of the flank 4 has two, for example, water-cooled cooling boxes 10a and 10b, which leave a passage opening 11 between them. whose cross-sectional shape is adapted to the cross-sectional shape of the head 2. The cooling surfaces of the passage opening

11 lie on the head 2 from three sides and leave the flank 4 free, i.e. uncooled.

A heating device 12 is assigned to the section of the flank 4 which remains uncooled. This heater

12 can be a precisely controllable gas burner, an induction coil or a radiant heater, in particular a laser heater. Conductive heating is also possible, for example heating in a correspondingly shielded metal bath or by means of a heating element which is brought into contact with the flank 4 of the edge profile 1.

As can also be seen from FIG. 6, the passage opening 11 is shaped in such a way that the transition region 4a between the head 2 and the flank 4 is still cooled. This results in a transition region 4a between the head 2 which remains hard and the additionally tempered flank 4, the hardness of which lies between that of the head 2 and the flank 4. The throughput speed v of the edge profile 1 and the heat supply Q through the heating device 12 are matched to one another in such a way that the heating temperature and the heating time - and thus the formation of a pearlitic structure - in the flank 4 - over the length of the edges ¬ profiles 1 can be kept constant.

The continuous system 9 for the additional partial starting of the flank 4 is further followed by a device 13 for slow and controlled cooling of the flank 4. The finished, heat-treated edge profile 1 is subsequently subjected to a bending deformation in a bending device 14, in which the flank 4 is stretched by a uniform amount. As a result of this bending deformation, the uniform curvature of the edge profile 1 which forms when the inner edge part is partially heated is reversed.

_ ₀ Finally, the finished heat-treated and gerich¬ preparing edge profile 1 in a punching station 15 with the Aus¬ recesses 5 and / or openings 6 provided. This process takes place either immediately after the heat treatment or, if appropriate, at another production site, for example at the production site of the

Ski manufacturer. Since the flank 4 to be provided with the recesses 5 or openings 6 has only a low hardness, the tool wear in this punching process is very low. 0

The system components shown schematically in FIG. 5 can be installed at a production site in a continuous production line. However, they can also be used at different production sites, as is symbolized in FIG. 5 by the parallel dividing lines in the flow arrows.

0

5

Claims

Patent claims

1. A method for producing a ski edge made of tempered steel, which has a head with the tread and a flank projecting into the body of the ski, which is thinner than the head and has a length of a plurality of punched-out recesses and / or openings is provided with the successive process steps listed below:

a) rolling or pulling the edge profile; b) tempering of the entire edge profile by heating to the hardening temperature and subsequent tempering; c) partial heating of the flank to a temperature greater than the tempering temperature with simultaneous cooling of the head; d) punching the recesses and openings in the flank,

characterized in that when the entire edge profile (1) is tempered, the deviation in the Rockwell hardness over the cross-section and the length of the edge profile (1) is set to less than 2 ° HRC, that the heating temperature and the heating duration when the flank is partially heated (4) are kept constant over the length of the edge profile (1) and that the edge profile (1) is subjected to constant bending deformation after partial heating and before punching, in which case the flank (4) is stretched by a constant amount . ΛO

2. The method according to claim 1, characterized gekenn¬ characterized in that when the entire edge profile (1) is subjected to a multi-stage pass compensation, in which the edge profile (1) first in a continuous metal bath rugged to a temperature just above the martensite start temperature (Ms) is cooled, then a structural transformation of the austenitic structure formed during the rugged cooling into the arctic structure is carried out with slow cooling under an air shower, and finally an tempering treatment is carried out under a protective gas.

3. Process according to claims 1 and 2, characterized in that the rugged cooling takes place in a lead bismuth continuous bath (8a) with a constant temperature of in particular 350 ° C.

4. The method according to any one of claims 1 to 3, characterized in that the tempering of the entire edge profile (1) to a Rockwell hardness of 50 ° -60 ° HRC and that the hardness of the flank (4) by partial heating is reduced to 30 ° -40 ° HRC.