NO161632B - PROCEDURES FOR HEAT CONFORMATION AA PREVENT UNDROVERS IN THE TRANSITIONAL BETWEEN THE SCREWS AND SCRAP PROFILES AND A DEVICE FOR IMPLEMENTING THE PROCEDURE - Google Patents
PROCEDURES FOR HEAT CONFORMATION AA PREVENT UNDROVERS IN THE TRANSITIONAL BETWEEN THE SCREWS AND SCRAP PROFILES AND A DEVICE FOR IMPLEMENTING THE PROCEDURE Download PDFInfo
- Publication number
- NO161632B NO161632B NO861149A NO861149A NO161632B NO 161632 B NO161632 B NO 161632B NO 861149 A NO861149 A NO 861149A NO 861149 A NO861149 A NO 861149A NO 161632 B NO161632 B NO 161632B
- Authority
- NO
- Norway
- Prior art keywords
- rail
- tongue
- heat treatment
- temperature
- burner
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 22
- 238000010438 heat treatment Methods 0.000 claims abstract description 24
- 230000008569 process Effects 0.000 claims abstract description 10
- 230000008859 change Effects 0.000 claims abstract description 9
- 238000006073 displacement reaction Methods 0.000 claims description 10
- 230000007704 transition Effects 0.000 claims description 9
- 238000001816 cooling Methods 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 238000007373 indentation Methods 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 238000009529 body temperature measurement Methods 0.000 claims description 2
- 238000002485 combustion reaction Methods 0.000 claims description 2
- 239000002737 fuel gas Substances 0.000 claims description 2
- 230000002441 reversible effect Effects 0.000 claims description 2
- 230000009466 transformation Effects 0.000 description 7
- 238000000137 annealing Methods 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000007493 shaping process Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/04—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rails
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
- Furnace Charging Or Discharging (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Laying Of Electric Cables Or Lines Outside (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
- Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
- Chutes (AREA)
- Seats For Vehicles (AREA)
- Screw Conveyors (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
- Paper (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
- Underground Or Underwater Handling Of Building Materials (AREA)
- Railway Tracks (AREA)
- Machines For Laying And Maintaining Railways (AREA)
- Manufacturing Of Electrical Connectors (AREA)
Abstract
Description
Oppfinnelsen vedrører en fremgangsmåte og en anordning for ved varmomformning å forhindre dannelsen av fordypninger i overgangsområdet mellom tunge-ende og tungeprofil ved skinner. The invention relates to a method and a device for preventing the formation of indentations in the transition area between tongue end and tongue profile by hot forming.
Tilformningen av tungeskinne-enden til vignole-skinneprofil skjer vanligvis ved varmformning i en senke. Den dertil nødvendige oppvarmning til omformningstemperaturen skjer i spesielle glødeovner, hvorved en tilsvarende lengde av skinnene da stikkes inn i ovnen. Tilformnings-prosessen er for det meste oppdelt i tre arbeidstrinn, og mellom disse blir det da nødvendig med en etteroppvarmning til omformningstemperatur. I retning mot den kolde skinne-ende oppstår det i profilet et temperaturovergangs-område som fører til en metallurgisk forandring i materi-alstrukturen. Denne strukturforandring, som ved perlit-tisk skinnestål spesielt oppstår i et temperaturområde fra 750° - 760°C, resulterer i en slags bløtglødnings-effekt. Jo lenger skinnestålet befinner seg i dette temperaturområde, jo større blir denne bløtglødningseffekt og dermed styrketapet. Lengden av strukturforandrings-sonen er direkte avhengig av omformningstemperaturen og av varigheten av varmeomformningsprosessen. Styrketapet i herdningssvekkelsen når størrelsesordener fra 150 - 200 N/mm<2>, og når hjul løper over, blir konsekvensen en fordypningslengde som ligger i et område på ca. 120 mm. The shaping of the tongue rail end into a vignole rail profile is usually done by hot forming in a sink. The necessary heating to the transformation temperature takes place in special annealing furnaces, whereby a corresponding length of the rails is then inserted into the furnace. The forming process is mostly divided into three work steps, and between these it is then necessary to reheat to the forming temperature. In the direction towards the cold rail end, a temperature transition area occurs in the profile which leads to a metallurgical change in the material structure. This structural change, which in the case of pearlitic rail steel particularly occurs in a temperature range from 750° - 760°C, results in a kind of soft annealing effect. The longer the rail steel is in this temperature range, the greater this soft annealing effect and thus the loss of strength. The length of the structural change zone is directly dependent on the transformation temperature and on the duration of the heat transformation process. The loss of strength in the weakening of hardening reaches orders of magnitude from 150 - 200 N/mm<2>, and when wheels run over, the consequence is an indentation length that lies in an area of approx. 120 mm.
En dannelse av fordypninger kan bare forhindres når lengdeområdet, hvor et hårdhetstap hhv. en fordypning observeres, begrenses til ca. 30 mm, idet en plastisk deformasjon på grunn av flatetrykkfrekvensen i avhengighet av hjuldiameteren og dermed en fordypningsdannelse da sikkert forhindres. Ved en begrensning av strukturforand-ringssonen til slike lengder er en avstøtning av rand-sonestrukturen tilstrekkelig til å forhindre en plastisk deformasjon. A formation of indentations can only be prevented when the length range, where a loss of hardness or a depression is observed, limited to approx. 30 mm, as a plastic deformation due to the surface pressure frequency depending on the wheel diameter and thus the formation of a depression is then certainly prevented. By limiting the structural change zone to such lengths, a rejection of the edge zone structure is sufficient to prevent a plastic deformation.
Fra DE-AS 25 41 978 er det allerede kjent en fremgangsmåte, hvor det foretas en varmebehandling av skinner for å danne en finperlittisk struktur. Idet man går ut fra en kold skinne, omfatter oppvarmningen hele skinne-lengden, hvorved det benyttes en gjennomløpsmetode. Etter opp-varmning til temperaturer over austenittiseringstemperaturen, gjennomføres styrt kjøling under anvendelse av trykkluft hhv. trykkluft med et væskeformet medium. From DE-AS 25 41 978, a method is already known, in which rails are heat treated to form a fine pearlitic structure. Starting from a cold rail, the heating covers the entire length of the rail, whereby a flow-through method is used. After heating to temperatures above the austenitizing temperature, controlled cooling is carried out using compressed air or compressed air with a liquid medium.
Formålet med oppfinnelsen er nå ved varmformningen å forhindre en reduksjon av materialstyrken i overgangsområdet til den kolde skinne-ende, hhv. å oppheve en allerede oppstått strukturendring i omformningsområdet. Til løsning av denne oppgave består fremgangsmåten ifølge oppfinnelsen hovedsakelig i at varmebehandlingen foretas samtidig med eller i umiddelbar tilslutning til varmomformningen av tungeskinne-enden, at overgangsområdet varmes opp til over austenittiseringstemperaturen, spesielt til over 860°C i en dybde på minst 7 mm, fortrinnsvis minst 10 mm, og fortrinnsvis høyst 25 mm, og at kjøling etter oppnådd austenittiseringstemperatur skjer i rolig luft. Ved denne varmebehandling gjenopprettes.den opprinnelige tilstand av den perlittiske struktur, idet den valgte inntrengningsdybde ble valgt med henblikk på at maksimal spenning vanligvis ligger ca. 7 mm under emnets overflate. En vesentlig faktor for varmebehandlingen er herved en kortest mulig oppvarmningstid til omformningstemperatur for å forhindre en utbredelse av varmen til den kolde skinne-ende. Etter tilformningen av tungeprofilet til vignolprofil befinner emnet seg i et temperaturområde på fra ca. 400° - 450°C i området for strukturend-ringssonen, hvorved oppvarmningstiden for den etter-følgende varmebehandling vil kunne reduseres vesentlig ved at varmebehandlingen foretas i umiddelbar tilslutning til varmformningen av tungeskinne-enden. På denne måte kan varmebehandlingen begrenses til en kort strekning. På fordelaktig måte begrenses varmebehandlingen til skinnehodet. Kjølingen skjer da i rolig luft, hvorved man opp-når den opprinnelige strukturtilstand før omformningen. The purpose of the invention is now to prevent a reduction of the material strength in the transition area to the cold rail end, or to undo a structural change that has already occurred in the conversion area. To solve this task, the method according to the invention mainly consists in the heat treatment being carried out at the same time as or in immediate connection with the heat forming of the tongue rail end, that the transition area is heated to above the austenitizing temperature, in particular to above 860°C in a depth of at least 7 mm, preferably at least 10 mm, and preferably no more than 25 mm, and that cooling after reaching the austenitizing temperature takes place in still air. During this heat treatment, the original state of the pearlitic structure is restored, as the selected penetration depth was chosen with a view to the maximum stress usually being approx. 7 mm below the surface of the workpiece. An important factor for the heat treatment is the shortest possible heating time to the transformation temperature in order to prevent the heat from spreading to the cold rail end. After shaping the tongue profile into a vignol profile, the workpiece is in a temperature range of from approx. 400° - 450°C in the area of the structural change zone, whereby the heating time for the subsequent heat treatment can be significantly reduced by the heat treatment being carried out immediately following the heat forming of the tongue rail end. In this way, the heat treatment can be limited to a short section. Advantageously, the heat treatment is limited to the rail head. The cooling then takes place in still air, whereby the original structural state is reached before the transformation.
Ifølge oppfinnelsen er det å foretrekke å gå frem slik at et lengdeområde på minst 150 mm, fortrinnsvis minst 300 mm, i overgangssonen mellom standardskinneprofil og tunge-ende underkastes varmebehandling. Det maksimale lengdeområde kan vanligvis, alt etter varigheten av varmomformningsprosessen, begrenses til under 900 mm. Styringen av varmebehandlingen foretas fortrinnsvis slik at lengden av den strukturendringssone som oppstår under omformningen av tungen holdes mindre enn 30 mm i skinnens lengderetning. According to the invention, it is preferable to proceed so that a length area of at least 150 mm, preferably at least 300 mm, in the transition zone between the standard rail profile and tongue end is subjected to heat treatment. The maximum length range can usually, depending on the duration of the hot forming process, be limited to less than 900 mm. The control of the heat treatment is preferably carried out so that the length of the structural change zone that occurs during the reshaping of the tongue is kept to less than 30 mm in the longitudinal direction of the rail.
Anordningen ifølge oppfinnelsen til utførelse av denne fremgangsmåte er hovedsakelig karakterisert ved at en brenner med styrbar flammetemperatur er lagret for forskyvning over skinnens overflate, idet dens forskyvningsstrekning fortrinnsvis begrenses ved hjelp av innstillbare endebrytere, at brenneren er lagret i en support med reverserbar drift, og at det er anordnet en temperaturmåleanordning for avføling av skinnens overflatetemperatur. Spesielt hensiktsmessig er herved en utførelse hvor brenngass- og/eller forbrenningsluft- hhv. oksygen-tilfør-selen og/eller den lineære forskyvningshastighet av brenneren langs skinnen reguleres i avhengighet av temperaturmåleverdier, hvorved temperaturmåleanordningen fortrinnsvis via styreledninger er forbundet med en prosessdatamaskin, som er forbundet med en styrbar ventilanordning på en gass-oksygenblandeanordning for brenneren. For å kunne ta hensyn til det ikke-lineære temperaturforløp i tempera-turovergangsområdet har et prosessdatamaskinstyrt anlegg vist seg spesielt fordelaktig. Brennerbundten er da montert på en support og varmebehandlingsstrekningen kan innstilles optimalt ved hjelp av endebrytere. Varmetil-førselen kan overvåkes ved hjelp av en f.eks. som miliskop eller pyrometer utformet temperaturmåleanordning, idet flammestyrken kan reguleres ved hjelp av en prosessdatamaskin og spesielt under oppvarmningsforløpet kan drives med sterkere flamme og på holdestadiet bare drives med svakere flamme. På denne måte kan en overopphetning av det område som allerede har oppnådd omformningstemperatur utlelukk.es. The device according to the invention for carrying out this method is mainly characterized in that a burner with controllable flame temperature is stored for displacement over the surface of the rail, its displacement range preferably being limited by means of adjustable limit switches, that the burner is stored in a support with reversible operation, and that a temperature measuring device is arranged for sensing the rail's surface temperature. Particularly appropriate here is an embodiment where fuel gas and/or combustion air or the oxygen supply and/or the linear displacement speed of the burner along the rail is regulated in dependence on temperature measurement values, whereby the temperature measuring device is preferably connected via control lines to a process computer, which is connected to a controllable valve device on a gas-oxygen mixing device for the burner. In order to be able to take into account the non-linear temperature course in the temperature transition area, a process computer-controlled plant has proven particularly advantageous. The burner bundle is then mounted on a support and the heat treatment length can be set optimally using limit switches. The heat supply can be monitored using an e.g. as a milliscope or pyrometer designed temperature measuring device, as the flame strength can be regulated by means of a process computer and especially during the heating process can be operated with a stronger flame and during the holding stage only operated with a weaker flame. In this way, overheating of the area that has already reached the transformation temperature can be avoided.
Oppfinnelsen skal i det følgende forklares nærmere ved hjelp av et utførelseseksempel på en anordning til utførelse av fremgangsmåten ifølge oppfinnelsen, som er In the following, the invention will be explained in more detail by means of an embodiment of a device for carrying out the method according to the invention, which is
vist på de vedføyede tegninger, hvor shown in the attached drawings, where
fig. 1 er et. skjematisk sideriss av anordningen ifølge oppfinnelsen, og fig. 1 is a. schematic side view of the device according to the invention, and
fig. 2 er et oppriss sett i retningen for pilen II på fig. 1. fig. 2 is an elevation seen in the direction of arrow II in fig. 1.
På fig. 1 er vist en forskyvbar support 1 som bærer en brenner 2. Ved brenneren 2 dreier det seg om en vann-kjølt bundtbrenner hvis flamme er rettet inn mot hodet 3 av en skinne 4. Brenneren står via gassledninger 5 i for-bindelse med en ventilanordning for en gass-oksygenblandeanordning, som er skjematisk vist ved 6 på fig. 2. I for-skyvningsbanen for supporten 1 er det anordnet endebrytere 7 og 8 som tjener til å begrense supportens forskyvningsstrekning. Over skinnen befinner det seg en temperaturmåleanordning 9, som via en signalledning 10 er forbundet med en prosessdatamaskin 11. En viseranordning for den målte temperatur er betegnet med 12. In fig. 1 shows a displaceable support 1 which carries a burner 2. The burner 2 is a water-cooled bundle burner whose flame is directed towards the head 3 of a rail 4. The burner is connected via gas lines 5 to a valve device for a gas-oxygen mixing device, which is schematically shown at 6 in fig. 2. Limit switches 7 and 8 are arranged in the advance displacement path for the support 1, which serve to limit the displacement distance of the support. Above the rail there is a temperature measuring device 9, which is connected via a signal line 10 to a process computer 11. A display device for the measured temperature is denoted by 12.
Slik det vil fremgå av fig. 2, er drivanordningen 13 for supporten anordnet på siden av skinnen. I området for den forskyvbare drivanordning befinner også ende-bryterne 7 og 8 for begrensning av forskyvningsstrekningen seg. Supporten er forskyvbar på et bord 14 og avstøttes på dette bord 14. Bevegelsesstrekningen for supporten blir vanligvis begrenset til 600 - 900 mm, mens den minste forskyvningsstrekning vanligvis velges til ca. 300 mm. Kjølingen i rolig luft har vist seg tilstrekkelig til å forhindre en uønsket glødning og utelukkende igjen til-veiebringe den tilstand som forelå før oppvarmningen til varmomformningstemperaturen. As will appear from fig. 2, the drive device 13 for the support is arranged on the side of the rail. The limit switches 7 and 8 for limiting the displacement distance are also located in the area of the displaceable drive device. The support is displaceable on a table 14 and is supported on this table 14. The range of movement for the support is usually limited to 600 - 900 mm, while the smallest displacement range is usually chosen to be approx. 300 mm. The cooling in still air has proven to be sufficient to prevent an unwanted annealing and exclusively restore the condition that existed before the heating to the heat transformation temperature.
Claims (7)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT0088785A AT391707B (en) | 1985-03-25 | 1985-03-25 | METHOD FOR PREVENTING ADJUSTMENT OF RAILS IN THE TRANSITIONAL AREA AND DEVICE FOR CARRYING OUT THIS METHOD |
Publications (3)
Publication Number | Publication Date |
---|---|
NO861149L NO861149L (en) | 1986-09-26 |
NO161632B true NO161632B (en) | 1989-05-29 |
NO161632C NO161632C (en) | 1989-09-06 |
Family
ID=3502117
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NO861149A NO161632C (en) | 1985-03-25 | 1986-03-21 | PROCEDURES FOR HEAT CONFORMATION AA PREVENT UNDROVERS IN THE TRANSITIONAL BETWEEN THE SCREWS AND SCRAP PROFILES AND A DEVICE FOR IMPLEMENTING THE PROCEDURE |
Country Status (9)
Country | Link |
---|---|
EP (1) | EP0199706B1 (en) |
AT (2) | AT391707B (en) |
CS (1) | CS266577B2 (en) |
DD (1) | DD244990A5 (en) |
DE (1) | DE3669538D1 (en) |
HU (1) | HU195545B (en) |
NO (1) | NO161632C (en) |
PL (1) | PL145456B1 (en) |
YU (2) | YU44545B (en) |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB448416A (en) * | 1933-09-06 | 1936-05-27 | Oxweld Railroad Service Compan | Improvements in or relating to the surface hardening of rails and to rails treated thereby |
US2484897A (en) * | 1946-10-22 | 1949-10-18 | Linde Air Prod Co | Apparatus for heat-treating surfaces of rails |
DE800867C (en) * | 1949-10-25 | 1950-12-11 | Deutsche Bundesbahn | Method and device for removing corrugations on rails |
BE626486A (en) * | 1961-12-27 | |||
DE2541978C3 (en) * | 1975-09-20 | 1978-08-24 | Butzbacher Weichenbau Gmbh, 6308 Butzbach | Process for the heat treatment of switch parts in a continuous process |
DE2821227C2 (en) * | 1978-05-16 | 1982-12-23 | Krupp Stahl Ag, 4630 Bochum | Process for the production of rails with reduced corrugation |
-
1985
- 1985-03-25 AT AT0088785A patent/AT391707B/en not_active IP Right Cessation
-
1986
- 1986-03-12 YU YU365/86A patent/YU44545B/en unknown
- 1986-03-19 CS CS861937A patent/CS266577B2/en unknown
- 1986-03-19 HU HU861158A patent/HU195545B/en not_active IP Right Cessation
- 1986-03-21 NO NO861149A patent/NO161632C/en unknown
- 1986-03-24 DE DE8686890076T patent/DE3669538D1/en not_active Expired - Lifetime
- 1986-03-24 AT AT86890076T patent/ATE51036T1/en not_active IP Right Cessation
- 1986-03-24 EP EP86890076A patent/EP0199706B1/en not_active Expired - Lifetime
- 1986-03-24 DD DD86288247A patent/DD244990A5/en not_active IP Right Cessation
- 1986-03-24 PL PL1986258590A patent/PL145456B1/en unknown
-
1987
- 1987-09-04 YU YU1643/87A patent/YU44642B/en unknown
Also Published As
Publication number | Publication date |
---|---|
ATA88785A (en) | 1990-05-15 |
HUT43655A (en) | 1987-11-30 |
YU44545B (en) | 1990-08-31 |
YU44642B (en) | 1990-10-31 |
CS266577B2 (en) | 1990-01-12 |
NO861149L (en) | 1986-09-26 |
YU164387A (en) | 1988-12-31 |
EP0199706A2 (en) | 1986-10-29 |
HU195545B (en) | 1988-05-30 |
DE3669538D1 (en) | 1990-04-19 |
YU36586A (en) | 1988-06-30 |
EP0199706B1 (en) | 1990-03-14 |
NO161632C (en) | 1989-09-06 |
CS193786A2 (en) | 1989-04-14 |
DD244990A5 (en) | 1987-04-22 |
PL145456B1 (en) | 1988-09-30 |
AT391707B (en) | 1990-11-26 |
ATE51036T1 (en) | 1990-03-15 |
EP0199706A3 (en) | 1987-05-13 |
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