PROCEDURE FOR THE PRODUCTION OF SHEET METALS, IN PARTICULAR FROM HEAVY PLATES, AND MECHANISM TO DURCHFUHRUNG THE PROCEDURE

The invention concerns a procedure for the production of sheet metals, in particular from Grobbleehen with a thickness over 100 now, by Warrnwalzen of Bramrnen, in particular from continuous casting slabs, in several passes, whereby the work material is deformed during n indest “LV of a pass between a pair of rollers alternating more strongly and more weakly, on which in one following “nStich the Diekenunterschiede becomes in the Längsrichümg of the work material again balanced, as well as a mechanism for the execution of the Verfahrens° it is well-known, rod-shaped material wavy to press and it to Baud iron to then roll out, for which rollers with wavy Mautelfläche are used. Further is well-known, for rolling out thin and broad-work material-rolls with welleuförmiger shaping to use, in order to facilitate pulling through of the Walzgntes. The steel structure needs heavy plates in larger sheet metal thicknesses in increasing measure; in particular for the building of nuclear power station heavy plates up to a thickness are needed by 350 mm. For the production of Grobbleahen within a thickness range from 100 to 350 mm Rohbramrnen with a weight are used from 20 t to approximately 100 t. With the production process of such Grcbbleahe errors arise with increasing slab ingot weight in intensified measure. The errors are interior errors, like Lockerstellenund splitting. A further error, which can occur during the production of thick austenitic Cr-Ni steel sheet metals, is coarse grain formation, which arises frequently due to a too small examination per pass - in the special in the core zone of the sheet metal -. The invention aims at the avoidance of these disadvantages and difficulties and places themselves the task to create a procedure of the initially described kind it made possible to manufacture even with sheet metal thicknesses over 100 mm error free sheet metals. Are loose places and splitting reliably brought to the Verschweil EN and it are the casting structure in the core zone of the work material into a rolling structure to be converted. This task is solved with a procedure of the initially designated kind thereby that with the weaker deformation the condition is kept a' directly or smaller than p and with the stronger deformation the Bedingungp smaller than o smaller than 2p, whereby “, o the gear parameters undp the friction angle to mean. This condition, which is kept according to invention during at least one Walzstiches, can also with several Stieben be fulfilled, does not have however not with each pass be used, i.e. several passes, in particular when spreading, can be accomplished, with which the work material remains alternating undeformed during a Walzstiches and smaller one deforms, than smaller than “smaller than 2p corresponds to the condition p. The work material is deformed favourably with the weaker deformation around 2 to 6% and with the stronger deformation around 5 to 12%. Appropriately the work material in several Walzstichen with alternating stronger and weaker deformation is rolled, whereby after each of these Walzstiche the thickness differences become balanced. After a preferential execution form the Verforrnungsbedingungen is adjusted in such a way that does not lie hold back ever of the difference of the largest and smallest thickness of the work material to their shortening star distance in the range between 0, 07 and 0.012. A mechanism, which at least a Arbeitswafzenpaar exhibits also over its entire extent of convex roller surface, suitable for execution DTE of procedure, it is characterized by the fact that at least that working rolls, over a circular cross-section exceeding collection exhibits oh savings alleles over its entire length. A preferential execution form is characterized by that at least one roller of the pair of working rolls exhibits an elliptical cross section, whereby the axis of rotation lies in the center of the ellipse, and that a circle-cylindrical Arbeitswafzenpaar is subordinate. After further Merlunalen invention exhibit two each other opposite working rolls elliptical cross section, whereby the ellipse shaft sections are parallel a working roll in the positions of the working rolls, in which the pass amgrößten and/or is smallest, to the appropriate ellipse shaft sections of the other working roll. Further one amounts to favourably the length of the short axle the cross section of the working roll forming ellipse 90 to 99% of the length of the long axle of the ellipse. The invention is more near described on the basis the schematisehen design as well as outer hand of two examples. In the design is a work material --1-- in the Längssctmitt after application of the Walzstiches according to invention represented, whereby the smallest thickness according to invention treated of the work material also--Hrnin--and largest thick also --Hmax-- is characteristic. Each other facing working rolls --2, 3-- exhibit an elliptical cross section. In the represented position of the working rolls the pass formed by them has the smallest height. The Ellipsenhalbachsun --A, b-- the working roll --2-- are parallel in this situation to the enteprechenden ellipse shaft sections --a', b' the working roll --3--. The axis of rotation leather Nr.346797 working roll lies in the center of the ellipse. According to invention rolled the work material exhibits wavy formed surfaces, whereby a wave valley of a wave mountain a distance, also --L-- designated eats, exhibits. This distance corresponds about quarter of the Walzenum£angee of the working rolls -- 3--. Approaches the determination of the gear parameter the elliptical working roll becomes appropriate by a circle-cylindrical roller --4-- with a Walzenradiue, that the Krürnmungskreisradius --5-- with the work material --1-- in contact of standing sheet corresponds to the elliptical working roll, replaced. B e i s p i e 1 1: Out of a steel quality, which is used for the production of low-alloy, heat resistant boiler plates, a block with the dimensions 3000 was poured × 2000 × 950 mm3, which on a Blschformat von6620 was rolled × 3600 × 240 rnm3. After heating up on 1280°C the block of a zweigerüstigen Grobblechstraße was supplied. As Vorgerast according to invention an ellipse roller stand with two working rolls was intended; llipsenaehsen that the identical elliptical working rolls 1000 and 960 mm amounted to. The stronger deformation corresponds to an attack angle of about 2405 with a decrease of 80 mm/pass '. Empiriech find-worth for the friction angle the p amounts to 16°30'. With this deformation thus the condition p of mine is fulfilled as A of mine as 2p (16030 ' smaller than 24o5' smaller than 33o). The smaller deformation entepricht with a decrease of 40 mm a gear parameter a' of about 15°35'. the empirically determined friction sign l amounts to again 16o30'. thereby is the condition A, equivalent or smaller than p (15035 ' smaller than 16°30y) fulfilled. A finishing stand was subordinate as four high mill with cylindrical working rolls. The rolling procedure is shown in the following tap plan 1. Hmin means the smallest thickness and Hmax the largest thickness of the work material after application of the according to invention rolling pass at the Ellipeenwalzengerüst. One began with each Walzstich according to invention in the position, in which the pass of the elliptical pair of rollers is largest. Walzrichtung lengths tricks widths tricks lengths pass No. 1 2 3 4 6 7 8 9 11 12 13 14 16 17 18 I4 nax (mm) 910,820,730 tap plan 1 ù cogging stand Ellipsenwalzengerüs t VerformungeHmin degree (%) (mm) of 4.2,870,780 4, 5, 5,690,680 0 640,630 0 590,580 0 540,530 0 490,480 0 440,430 0 390 grade of deformation (%) 8.5,9.3 11 5.9,6.3,6.9,7.5,8.3,9.3 far rolling August in usual way at the finishing stand finishing stand cylindrical working rolls H (mm) 860,770,680,630,580,530,480,430,380,240 during the passes 1, 3 and 5 the work material became alternating strengthens and more weakly according to indicated in former times Conditions .a' directly or smaller than p and/or p smaller than A of mine than 2p deforms. The passes 2, 4 and 6 are Plaustiche, in which the giant differences become balanced. With the Stfchen 7, 9, 11, 13, 15 and 17 in such a manner is the roll adjustment of the ellipse rollers that the work material remains alternating undeformed during a pass and smaller is deformed than the condition p smaller than A smaller than 2p corresponds. The passes 8, 10, 12, 14, 16 and 18 are again plan passes for the reconciliation of the Dicl nunterschiede. An investigation erzeugtenBlechcs by means of an ultrasonic testing resulted in a perfect quality without errors. Samples were taken dern head and basing of the sheet metal. The metallografische findings showing oh beginnings with diluted nitric acid a middle grain size after ASTM from 6 to 7. Splitting and loosening hurrying could not be determined. B e i s pi e 1 2: A continuous casting slab from a Cr-Ni steel of the type 18/8 was warmed up in the pusher type furnace to 1220°C and supplied to the ellipse roller stand according to invention for deformation. The Stranggu slab had the dimensions 3000 × 1600 × 300 mm3. From this a sheet metal with the dimensions 6000 × 2200 × 110 mm3 was produced. The ellipse axles that working rolls amounted to 1010 and 995 mm. The subordinate Fertigg œ prepare was equipped with cylindrical working rolls. The continuous casting slab was rolled in accordance with below stated tap plan. The stronger deformation corresponds with a decrease of 50 mm to a gear parameter o of about 18°30 of the friction angles p is, as was empirically determined, 16o30'. it is thus with the stronger deformation the condition p smaller than Œ smaller than 2p (16o30' smaller than 18o30' smaller than 33o) fulfilled. Dle smaller deformation corresponds to a gear parameter o of about 15°5' with a decrease von35 mm, whereby thus the Bedingungen' is fulfilled directly or smaller than p (15°5' smaller than 16o30'). Stichplau 2 Walzrichtung lengths tricks widths tricks lengths pass No. 1 2 3 4 cogging stand Ellips more enwalzenger is Hmax Hmin grade of deformation (mm) (mm) of 250 11, 7 - RST, 6,235 O - 11.3 220 0 12, 0,265,250,235 finishing stand cylindrical working rolls H (mm) 220 6 7 205,190 6, 8 - 13, 7,190,175 0 14, 6,175,160 0 15.8 I far rolling in usual way at the finishing stand 110 the passes 1 to 3 were accomplished at the ellipse roller stand. While the passes 2 and 3 is the grade of deformation dependent on that rolling savings size with puncturing, i.e. dependent on in which position the elliptical working rollers are when seizing the work material. Subsequently, at pass 3 a longitudinal pass at the finishing stand took place for the reconciliation of the thickness differences. Spreading took place at the ellipse roller stand, whereby for the passes 6 and 7 the grade of deformation was dependent in the same way as for the passes 2 and 3 on the size of the pass when puncturing. As one showed metallographischc investigation, the sheet metal was free from rough core. The grain size after ASTM was determined with 5 to 6.