EP0144694A2 - Method of making semi-finished products consisting of stainless austenitic or martensitic steel - Google Patents

Method of making semi-finished products consisting of stainless austenitic or martensitic steel Download PDF

Info

Publication number
EP0144694A2
EP0144694A2 EP84112965A EP84112965A EP0144694A2 EP 0144694 A2 EP0144694 A2 EP 0144694A2 EP 84112965 A EP84112965 A EP 84112965A EP 84112965 A EP84112965 A EP 84112965A EP 0144694 A2 EP0144694 A2 EP 0144694A2
Authority
EP
European Patent Office
Prior art keywords
temperature
workpiece
last
water
solution annealing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP84112965A
Other languages
German (de)
French (fr)
Other versions
EP0144694A3 (en
Inventor
Hans Dr. Rydstad
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BBC Brown Boveri AG Germany
Original Assignee
Brown Boveri und Cie AG Germany
BBC Brown Boveri AG Germany
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Brown Boveri und Cie AG Germany, BBC Brown Boveri AG Germany filed Critical Brown Boveri und Cie AG Germany
Publication of EP0144694A2 publication Critical patent/EP0144694A2/en
Publication of EP0144694A3 publication Critical patent/EP0144694A3/en
Withdrawn legal-status Critical Current

Links

Images

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
    • C21D11/00—Process control or regulation for heat treatments
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys

Definitions

  • the invention relates to a process for the production of semi-finished products from a stainless austenitic or martensitic steel according to the preamble of claim 1.
  • Stainless austenitic and especially martensitic steels are preferably subjected to a heat treatment in order to improve their corrosion behavior or their mechanical properties, in particular their strength.
  • the heat treatment generally consists of solution annealing the workpiece and then quenching it in water. For various reasons, this is done in a conventional manner for rolling stock by means of a separate heat treatment after the last hot rolling pass. The cooling rate would usually be too slow for direct quenching from the rolling heat.
  • the invention is based on the object of specifying a method which enables the production of semi-finished products, in particular rolled material, from an austenitic or martensitic steel in a continuous, simple and inexpensive manner.
  • 1 shows the structure of a device for carrying out a continuous process for rolling stock with a corresponding temperature diagram of the heat treatment.
  • 1 is the workpiece (rolling stock) that moves from left to right according to the arrows.
  • 2 are rollers of the roll stand arranged in pairs, it being possible for individual or all of the rollers 2 to be equipped with a roller heater 3. The direction of rotation of the rollers 2 is indicated by arrows.
  • 4 are two-color pyrometers for recording the temperature at different locations in the rolling process, in particular for determining the final roll temperature.
  • 5 is an inductive heater for the workpiece, which is made up of several individual coils.
  • 6 represents a water tank and 7 the associated, suitably arranged quenching showers for the workpiece 1.
  • the quenching showers 7 can be seen in cross-section in the form of a ring (for example for a round or square workpiece) or in pairs be arranged with water jets inclined to the feed direction (for example for a flat, band-shaped or plate-shaped workpiece 1).
  • 8 is a controller for regulating the heating power (for each induction coil individually) of 5 and the water inflow and outflow of 6 and 7. In this controller 8, as parameters other than the
  • the temperature profile T of the workpiece 1 as a function of its location (path) s is shown in the lower part of FIG. a is the lower limit of the quenching temperature required for the respective workpiece 1, which depends on the shape, dimension and material, b shows the temperature profile in the case of a high final roll temperature, at which no additional heating of the workpiece 1 is required.
  • Curve c applies if the final roll temperature is too low for a direct quenching (as a rule) and the workpiece 1 also has to be heated again by means of heater 5.
  • d represents the temperature profile which the workpiece 1 assumes when the roller heating 3 has the effect that premature cooling is largely prevented.
  • the rolling temperature then assumes an average, approximately constant value over the entire course of the process, which is sufficiently high above a over the entire cross-section of the workpiece in order to ensure optimal microstructure formation after quenching.
  • Curve e represents the temperature T ( ⁇ C) of the workpiece 1 as a function of the time t (sec).
  • the final roll temperature after the last roll pass is 900 ° C, the quenching temperature 1070 ° C.
  • Curve f represents the temperature T ( ⁇ C) of the workpiece 1 as a function of the time t (sec).
  • the final roll temperature after the last roll pass is 900 ° C.
  • the quenching temperature is 1000 ° C.
  • a workpiece 1 with a rectangular end cross-section of 15 mm x 40 mm was hot-rolled in several passes from a stainless austenitic steel using the continuous process.
  • the material had the following composition:
  • the hot rolling and the further treatment were carried out in a device according to curve 1 shown schematically in FIG. 1.
  • the rolling temperature gradually decreased from initially 1200 ° C to 900 ° C after the last stitch (approximately entry temperature into the furnace provided with inductive heating 5).
  • the workpiece 1 was then heated to a temperature of 1070 ° C. within 20 seconds by means of inductive heating 5 and then immediately quenched with water using device 6/7 (cf. curve e in FIG. 2).
  • the mean grain size of the finished rolled stock was 10 to 20 ⁇ m and its average Vickers hardness was 175 units (corresponding to a calculated tensile strength of approx. 560 MPa).
  • the material values of the steel and the dimensions of the workpiece were entered into the control unit 9 and the temperatures were monitored by means of the pyrometer 4.
  • the required power of the heater 5 was then automatically determined on the basis of calculated tables and functions and switched on by means of the controller 8 poses. The same applies to the operating parameters for the quenching (water tank 6 and quenching showers 7).
  • a workpiece 1 with a rectangular end cross-section of 15 mm x 40 mm was hot-rolled in several passes from a stainless martensitic steel using the continuous process.
  • the material had the following composition:
  • This alloy was processed according to the device according to FIG. 1 and according to curve c of this figure.
  • the final roll temperature at the end of the last pass was 900 ° C.
  • the further processing was carried out according to curve f, FIG. 3.
  • the workpiece 1 was then heated to a temperature of 1000 ° C. within 12 seconds by means of inductive heating 5 and then immediately quenched using water.
  • the workpiece 1 was then heated again to 570 ° C. in a conventional manner for the purpose of tempering and then cooled in air.
  • the finished treated steel had a tensile strength of approx. 990 MPa.
  • the invention is not limited to the examples. According to the above procedure, most of the corro treat ion-resistant austenitic, martensitic and ferritic steels. This includes the following austenitic classes in particular:
  • ferritic and martensitic steels also fall under the classes mentioned:
  • the method can also be carried out in such a way that the last rolling passes are carried out at a temperature high enough to directly quench the workpiece 1 from the solution annealing temperature after the last pass without additional heating (curve b in FIG. 1).
  • the inductive heating 5 can basically be accommodated in a continuous or holding furnace.
  • the method can also be carried out using a roller heater 3 according to curve d (see FIG. 1) that is provided for at least the last phase of the rolling process.
  • the roller heater 3 is also controlled by the devices 8 and 9 or separately supervised.
  • the final roll temperature then corresponds approximately to the quenching temperature (in the present case approx. 1000 to 1100 ° C).
  • the air cooling of the workpiece 1 carried out according to FIG. 3 after tempering can optionally also be replaced in a conventional manner by water cooling.
  • the degree of deformation ⁇ should be at least 0.8.
  • ⁇ is defined as follows:

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 Steel (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)

Abstract

Semi-finished products of stainless austenitic Cr/Ni(Mo) or martensitic Cr(Mo) steels are produced from rolled raw material directly from the rolling heat, avoiding interannealing, by quenching the workpiece (1) in water by means of quenching sprays (7) fed from a water tank (6), either directly (curve b) from a sufficiently high rolling end temperature corresponding to the solution annealing temperature (minimum quench temperature) or after additional heating to the quench temperature (curve c) by means of inductive heating (5) or from a temperature held by means of roller heating (3) approximately at the required quench temperature (curve d). The process sequence is here controlled by means of temperature monitoring of the workpiece (1), detected by a pyrometer (4), via a control instrument (9) feeding the set parameters, and a controller (8), the speed of the rollers (2) also being taken into account. <IMAGE>

Description

Die Erfindung geht aus von einem Verfahren zur Herstellung von Halbzeug aus einem rostfreien austenitischen oder martensitischen Stahl nach der Gattung des Oberbegriffs des Anspruchs 1.The invention relates to a process for the production of semi-finished products from a stainless austenitic or martensitic steel according to the preamble of claim 1.

Rostfreie austenitische und vor allem martensitische Stähle werden zwecks Verbesserung ihres Korrosionsverhaltens bzw. ihrer mechanischen Eigenschaften, insbesondere der Festigkeit bevorzugt einer Wärmebehandlung unterzogen. Dies gilt vor allem für Halbzeug und insbesondere für Walzmaterial. Die Wärmebehandlung besteht im allgemeinen in einem Lösungsglühen des Werkstücks und in einem anschliessenden Abschrecken in Wasser. Dies geschieht aus verschiedenen Gründen bei Walzmaterial in herkömmlicher Weise durch eine separate Wärmebehandlung nach dem letzten Warmwalzstich. Für ein direktes Abschrecken aus der Walzhitze wäre meistens die Abkühlungsgeschwindigkeit zu niedrig.Stainless austenitic and especially martensitic steels are preferably subjected to a heat treatment in order to improve their corrosion behavior or their mechanical properties, in particular their strength. This applies above all to semi-finished products and in particular to rolled material. The heat treatment generally consists of solution annealing the workpiece and then quenching it in water. For various reasons, this is done in a conventional manner for rolling stock by means of a separate heat treatment after the last hot rolling pass. The cooling rate would usually be too slow for direct quenching from the rolling heat.

Für die wirtschaftliche Herstellung von gewissem Halbzeug in grösseren Mengen kommt vornehmlich die Fliessfertigung in Frage. Zu diesem Zweck sind entsprechende Durchlaufverfahren und die zugehörigen Anlagen entwickelt worden (siehe z.B. Georg Mesbert, "Die Abschreckung von Rohren und Stäben im Durchlauf bei der Wärmebehandlung von Stahl", Stahl und Eisen 101, 16. November 1981, S. 1419-1425).For the economical production of certain semi-finished products in large quantities, flow production is the main thing Question. Corresponding continuous processes and the associated systems have been developed for this purpose (see, for example, Georg Mesbert, "The quenching of pipes and rods in the continuous process in the heat treatment of steel", Stahl und Eisen 101, November 16, 1981, pp. 1419-1425) .

Die bekannten herkömmlichen Verfahren zur Verbesserung der Eigenschaften von austenitischen und martensitischen Stählen sind vergleichsweise zeitraubend und umständlich und erfordern umfangreiche Anlagen. Es besteht daher ein Bedürfnis zur Weiterentwicklung und Vereinfachung dieser Verfahren.The known conventional methods for improving the properties of austenitic and martensitic steels are comparatively time-consuming and cumbersome and require extensive systems. There is therefore a need to further develop and simplify these processes.

Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren anzugeben, das die Herstellung von Halbzeug, insbesondere Walzmaterial aus einem austenitischen oder martensitischen Stahl in kontinuierlicher, einfacher und kostengünstiger Weise ermöglicht.The invention is based on the object of specifying a method which enables the production of semi-finished products, in particular rolled material, from an austenitic or martensitic steel in a continuous, simple and inexpensive manner.

Diese Aufgabe wird erfindungsgemäss durch die im kennzeichnenden Teil des Anspruchs 1 angegebenen Merkmale gelöst.According to the invention, this object is achieved by the features specified in the characterizing part of claim 1.

Die Erfindung wird anhand der nachfolgenden, durch Figuren erläuterten Ausführungsbeispiele beschrieben.The invention is described on the basis of the following exemplary embodiments explained by figures.

Dabei zeigt:

  • Fig. 1 den schematischen Aufbau einer Vorrichtung zur Durchführung des Verfahrens mit dem entsprechenden Temperaturschaubild der Wärmebehandlung,
  • Fig. 2 ein Diagramm des Temperaturverlaufs des Verfahrens in Funktion der Zeit für einen austenitischen Stahl,
  • Fig. 3 ein Diagramm des Temperaturverlaufs des Verfahrens in Funktion der Zeit für einen martensitischen Stahl.
It shows:
  • 1 shows the schematic structure of a device for carrying out the method with the corresponding temperature diagram of the heat treatment,
  • 2 shows a diagram of the temperature profile of the method as a function of time for an austenitic steel,
  • Fig. 3 is a diagram of the temperature profile of the process as a function of time for a martensitic steel.

In Fig. 1 ist der Aufbau einer Vorrichtung zur Durchführung eines Durchlaufverfahrens für Walzgut mit entsprechendem Temperaturschaubild der Warmbehandlung dargestellt. 1 ist das Werkstück (Walzgut), das sich den Pfeilen gemäss von links nach rechts bewegt. 2 sind jeweils paarweise angeordnete Walzen des Walzgerüstes, wobei einzelne oder alle Walzen 2 mit einer Walzenheizung 3 ausgerüstet sein können. Die Umdrehungsrichtung der Walzen 2 ist durch Pfeile angedeutet. 4 sind Zweifarben-Pyrometer zur Erfassung der Temperatur an verschiedenen Orten des Walzprozesses, insbesondere zur Bestimmung der Walzendtemperatur. 5 ist eine aus mehreren Einzelspulen aufgebaute induktive Heizung für das Werkstück. 6 stellt einen Wasserbehälter und 7 die dazugehörigen, in geeigneter Weise angeordneten Abschreckbrausen für das Werkstück 1 dar. Je nach Querschnittsform und Profil des Werkstücks 1 können die Abschreckbrausen 7 im Querschnitt gesehen in Form eines Ringes (z.B. für ein rundes oder quadratisches Werkstück) oder paarweise mit zur Vorschubrichtung geneigten Wasserstrahlen (z.B. für ein flaches, band- oder plattenförmiges Werkstück 1) angeordnet sein. 8 ist ein Regler zur Regulierung der Heizleistung (für jede Induktionsspule individuell) von 5 und des Wasserzu- bzw. Abflusses von 6 und 7. In diesem Regler 8 werden als Kenngrössen ausser der über1 shows the structure of a device for carrying out a continuous process for rolling stock with a corresponding temperature diagram of the heat treatment. 1 is the workpiece (rolling stock) that moves from left to right according to the arrows. 2 are rollers of the roll stand arranged in pairs, it being possible for individual or all of the rollers 2 to be equipped with a roller heater 3. The direction of rotation of the rollers 2 is indicated by arrows. 4 are two-color pyrometers for recording the temperature at different locations in the rolling process, in particular for determining the final roll temperature. 5 is an inductive heater for the workpiece, which is made up of several individual coils. 6 represents a water tank and 7 the associated, suitably arranged quenching showers for the workpiece 1. Depending on the cross-sectional shape and profile of the workpiece 1, the quenching showers 7 can be seen in cross-section in the form of a ring (for example for a round or square workpiece) or in pairs be arranged with water jets inclined to the feed direction (for example for a flat, band-shaped or plate-shaped workpiece 1). 8 is a controller for regulating the heating power (for each induction coil individually) of 5 and the water inflow and outflow of 6 and 7. In this controller 8, as parameters other than the

4 gemessenen Temperaturen T1 ... T die Dimensionen des Werkstücks 1 und die Endwalzgeschwindigkeit sowie ein zuvor ausgewähltes, vom zu behandelnden Werkstoff abhängiges zuvor aufgrund von Tabellen errechnetes Programm mittels Steuergerät 9 eingegeben.4 measured temperatures T 1 ... T, the dimensions of the workpiece 1 and the final rolling speed, and a previously selected program, which is dependent on the material to be treated and previously calculated on the basis of tables, are entered by means of control unit 9.

Der Temperaturverlauf T des Werkstücks 1 in Funktion seines Ortes (Weges) s ist im unteren Teil der Figur l dargestellt. a ist die untere Grenze der erforderlichen Abschrecktemperatur für das jeweilige Werkstück 1, die sich nach Form, Dimension und Werkstoff richtet, b zeigt den Temperaturverlauf für den Fall hoher Walzendtemperatur, bei der keine zusätzliche Aufheizung des Werkstücks 1 erforderlich ist. Kurve c gilt, wenn die Walzendtemperatur für ein unmittelbares Abschrecken zu tief liegt (Regelfall) und das Werkstück 1 mittels Heizung 5 zusätzlich wieder aufgeheizt werden muss. d stellt den Temperaturverlauf dar, den das Werkstück l annimmt, wenn durch die Walzenheizung 3 bewirkt wird, dass eine vorzeitige Abkühlung weitgehend unterbunden wird. Die Walztemperatur nimmt dann über den ganzen Verlauf des Prozesses einen mittleren, annähernd konstanten Wert an, welcher über den ganzen Querschnitt des Werkstücks genügend hoch oberhalb a liegt, um eine optimale Gefügeausbildung nach dem Abschrecken zu gewährleisten.The temperature profile T of the workpiece 1 as a function of its location (path) s is shown in the lower part of FIG. a is the lower limit of the quenching temperature required for the respective workpiece 1, which depends on the shape, dimension and material, b shows the temperature profile in the case of a high final roll temperature, at which no additional heating of the workpiece 1 is required. Curve c applies if the final roll temperature is too low for a direct quenching (as a rule) and the workpiece 1 also has to be heated again by means of heater 5. d represents the temperature profile which the workpiece 1 assumes when the roller heating 3 has the effect that premature cooling is largely prevented. The rolling temperature then assumes an average, approximately constant value over the entire course of the process, which is sufficiently high above a over the entire cross-section of the workpiece in order to ensure optimal microstructure formation after quenching.

In Fig. 2 ist ein Diagramm des Temperaturverlaufs des Verfahrens in Funktion der Zeit für ein Werkstück 1 aus einem austenitischen Stahl dargestellt. Kurve e stellt die Temperatur T (οC) des Werkstückes 1 in Funktion der Zeit t (sec) dar. Die Walzendtemperatur nach dem letzten Walzstich beträgt 900°C, die Abschrecktemperatur 1070°C.2 shows a diagram of the temperature profile of the method as a function of time for a workpiece 1 made of an austenitic steel. Curve e represents the temperature T (οC) of the workpiece 1 as a function of the time t (sec). The final roll temperature after the last roll pass is 900 ° C, the quenching temperature 1070 ° C.

Fig. 3 zeigt ein Diagramm des Temperaturverlaufs des Verfahrens in Funktion der Zeit für ein Werkstück 1 aus einem martensitischen Stahl. Kurve f stellt die Temperatur T (οC) des Werkstückes 1 in Funktion der Zeit t (sec) dar. Die Walzendtemperatur nach dem letzten Walzstich beträgt 900 C, die Abschrecktemperatur 1000°C.3 shows a diagram of the temperature profile of the method as a function of time for a workpiece 1 made of a martensitic steel. Curve f represents the temperature T (οC) of the workpiece 1 as a function of the time t (sec). The final roll temperature after the last roll pass is 900 ° C., the quenching temperature is 1000 ° C.

Ausführungsbeispiel I:Embodiment I:

Siehe Fig. 1 und Fig. 2:See Figures 1 and 2:

Aus einem rostfreien austenitischen Stahl wurde in mehreren Stichen nach dem Durchlaufverfahren ein Werkstück 1 mit einem rechteckigen Endquerschnitt von 15 mm x 40 mm warmgewalzt. Der Werkstoff hatte die nachfolgende Zusammensetzung:

Figure imgb0001
Figure imgb0002
Figure imgb0003
Figure imgb0004
Figure imgb0005
 A workpiece 1 with a rectangular end cross-section of 15 mm x 40 mm was hot-rolled in several passes from a stainless austenitic steel using the continuous process. The material had the following composition:
Figure imgb0001
Figure imgb0002
Figure imgb0003
Figure imgb0004
Figure imgb0005

Das Warmwalzen sowie die Weiterbehandlung erfolgte in einer gemäss Fig. 1 schematisch dargestellten Vorrichtung entsprechend Kurve c. Die Walztemperatur fiel sukzessive von anfangs 1200°C auf 900°C nach dem letzten Stich ab (ungefähr Eintrittstemperatur in den mit induktiver Heizung 5 versehenen Ofen). Das Werkstück 1 wurde nun mittels induktiver Heizung 5 innert 20 sec auf eine Temperatur von 1070°C aufgeheizt und anschliessend sofort mittels Vorrichtung 6/7 mit Wasser abgeschreckt (Vergl. Kurve e in Fig. 2). Die mittlere Korngrösse des fertig behandelten Walzgutes betrug 10 bis 20 µm und seine durchschnittliche Vickershärte 175 Einheiten (entsprechend einer errechneten Zugfestigkeit von ca. 560 MPa).The hot rolling and the further treatment were carried out in a device according to curve 1 shown schematically in FIG. 1. The rolling temperature gradually decreased from initially 1200 ° C to 900 ° C after the last stitch (approximately entry temperature into the furnace provided with inductive heating 5). The workpiece 1 was then heated to a temperature of 1070 ° C. within 20 seconds by means of inductive heating 5 and then immediately quenched with water using device 6/7 (cf. curve e in FIG. 2). The mean grain size of the finished rolled stock was 10 to 20 µm and its average Vickers hardness was 175 units (corresponding to a calculated tensile strength of approx. 560 MPa).

Bei der Durchführung des Verfahrens wurden die Werkstoffwerte des Stahles sowie die Dimensionen des Werkstückes in das Steuergerät 9 eingegeben und die Temperaturen mittels Pyrometer 4 überwacht. Aufgrund von berechneten Tabellen und Funktionen wurde dann die erforderliche Leistung der Heizung 5 automatisch bestimmt und mittels Regler 8 eingestellt. Desgleichen die Betriebsparameter für das Abschrecken (Wasserbehälter 6 und Abschreckbrausen 7).When carrying out the method, the material values of the steel and the dimensions of the workpiece were entered into the control unit 9 and the temperatures were monitored by means of the pyrometer 4. The required power of the heater 5 was then automatically determined on the basis of calculated tables and functions and switched on by means of the controller 8 poses. The same applies to the operating parameters for the quenching (water tank 6 and quenching showers 7).

Ausführungsbeispiel II:Working example II:

Siehe Fig. 1 und Fig. 3:See Figures 1 and 3:

Aus einem rostfreien martensitischen Stahl wurde in mehreren Stichen nach dem Durchlaufverfahren ein Werkstück 1 mit einem rechteckigen Endquerschnitt von 15 mm x 40 mm warmgewalzt. Der Werkstoff hatte die nachfolgende Zusammensetzung:

Figure imgb0006
Figure imgb0007
Figure imgb0008
Figure imgb0009
 A workpiece 1 with a rectangular end cross-section of 15 mm x 40 mm was hot-rolled in several passes from a stainless martensitic steel using the continuous process. The material had the following composition:
Figure imgb0006
Figure imgb0007
Figure imgb0008
Figure imgb0009

Die Verarbeitung dieser Legierung erfolgte gemäss Vorrichtung nach Fig. 1 und entsprechend Kurve c dieser Figur. Dabei betrug die Walzendtemperatur am Schluss des letzten Stiches 900°C. Die Weiterverarbeitung wurde gemäss Kurve f, Fig. 3 vorgenommen. Danach wurde das Werkstück 1 mittels induktiver Heizung 5 innert 12 sec. auf eine Temperatur von 1000°C erwärmt und dann sofort mittels Wasser abgeschreckt. Daraufhin wurde das Werkstück 1 zwecks Anlassen in konventioneller Weise nochmals auf 570°C erwärmt und dann an Luft abgekühlt. Der fertig behandelte Stahl wies eine Zugfestigkeit von ca. 990 MPa auf.This alloy was processed according to the device according to FIG. 1 and according to curve c of this figure. The final roll temperature at the end of the last pass was 900 ° C. The further processing was carried out according to curve f, FIG. 3. The workpiece 1 was then heated to a temperature of 1000 ° C. within 12 seconds by means of inductive heating 5 and then immediately quenched using water. The workpiece 1 was then heated again to 570 ° C. in a conventional manner for the purpose of tempering and then cooled in air. The finished treated steel had a tensile strength of approx. 990 MPa.

Alle detaillierten Verfahrensschritte wurden nach dem gleichen, unter Beispiel I geschildeten Prinzip durchgeführt.All detailed process steps were carried out according to the same principle as described in Example I.

Die Erfindung ist nicht auf die Beispiele beschränkt. Nach dem vorgenannten Verfahren lassen sich die meisten korrosionsbeständigen austenitischen, martensitischen und ferritischen Stähle behandeln. Darunter fallen insbesondere folgende austenitische Klassen:

Figure imgb0010
Figure imgb0011
Figure imgb0012
Figure imgb0013
Figure imgb0014
 The invention is not limited to the examples. According to the above procedure, most of the corro treat ion-resistant austenitic, martensitic and ferritic steels. This includes the following austenitic classes in particular:
Figure imgb0010
Figure imgb0011
Figure imgb0012
Figure imgb0013
Figure imgb0014

Ferner fallen u.a. folgende ferritischen bzw. martensitischen Stähle unter die genannten Klassen:

Figure imgb0015
Figure imgb0016
Figure imgb0017
Figure imgb0018
Figure imgb0019
 The following ferritic and martensitic steels also fall under the classes mentioned:
Figure imgb0015
Figure imgb0016
Figure imgb0017
Figure imgb0018
Figure imgb0019

Unter gewissen Umständen lässt sich das Verfahren auch derart durchführen, dass die letzten Walzstiche bei einer Temperatur erfolgen, welche genügend hoch liegt, um das Werkstück 1 nach dem letzten Stich ohne zusätzliche Erwärmung aus der Lösungsglühtemperatur direkt abzuschrecken (Kurve b in Fig. 1).Under certain circumstances, the method can also be carried out in such a way that the last rolling passes are carried out at a temperature high enough to directly quench the workpiece 1 from the solution annealing temperature after the last pass without additional heating (curve b in FIG. 1).

Die induktive Heizung 5 kann grundsätzlich in einem Durchlauf- oder Halteofen untergebracht sein.The inductive heating 5 can basically be accommodated in a continuous or holding furnace.

Das Verfahren lässt sich prinzipiell auch unter Ausnutzung einer mindestens für die letzte Phase des Walzprozesses vorgesehenen Walzenheizung 3 gemäss Kurve d (siehe Fig. 1) durchführen. In diesem Falle wird die Walzenheizung 3 ebenfalls durch die Geräte 8 und 9 gesteuert oder separat überwacht. Die Walzendtemperatur entspricht dann ungefähr der Abschrecktemperatur (im vorliegenden Fall ca. 1000 bis 1100°C).In principle, the method can also be carried out using a roller heater 3 according to curve d (see FIG. 1) that is provided for at least the last phase of the rolling process. In this case, the roller heater 3 is also controlled by the devices 8 and 9 or separately supervised. The final roll temperature then corresponds approximately to the quenching temperature (in the present case approx. 1000 to 1100 ° C).

Die gemäss Fig. 3 nach dem Anlassen durchgeführte Luftabkühlung des Werkstückes 1 kann gegebenenfalls in herkömmlicher Weise auch durch eine Wasserabkühlung ersetzt werden.The air cooling of the workpiece 1 carried out according to FIG. 3 after tempering can optionally also be replaced in a conventional manner by water cooling.

Es ist darauf zu achten, dass die Verformung während des Walzprozesses genügend hoch ist, damit eine vollständige Rekristallisation des Walzgutes gewährleistet wird. Im allgemeinen soll der Verformungsgrad ε mindestens 0,8 betragen. Dabei ist ε wie folgt definiert:

Figure imgb0020
Figure imgb0021
Figure imgb0022
 It is important to ensure that the deformation during the rolling process is sufficiently high to ensure that the rolling stock is completely recrystallized. In general, the degree of deformation ε should be at least 0.8. Here ε is defined as follows:
Figure imgb0020
Figure imgb0021
Figure imgb0022

Das neue Verfahren zeichnet sich durch folgende Merkmale aus:

  • - Keine zusätzliche Wärmebehandlung.
  • - Keine zusätzliche Handhabung mit den entsprechenden Umtrieben wie Transport, Lagerung etc.
  • - Geringerer Verzug des Walzgutes.
  • - Kürzere Durchlaufzeit in der Produktion.
  • - Vereinfachter, automatischer Ablauf des Verfahrens.
The new process is characterized by the following features:
  • - No additional heat treatment.
  • - No additional handling with the corresponding activities like transport, storage etc.
  • - Less warpage of the rolling stock.
  • - Shorter lead times in production.
  • - Simplified, automatic procedure.

Claims (4)

1. Verfahren zur Herstellung von Halbzeug aus einem rostfreien austenitischen oder martensitischen Stahl, ausgehend von gewalztem Vormaterial, wobei das Werkstück (1) einem weiteren Walzprozess sowie einer eine Lösungsglühung und anschliessende Wasserabschreckung beinhaltenden Wärmebehandlung unterworfen wird, dadurch gekennzeichnet, dass die letzten in einer Hitze durchgeführten Walzstiche einen Verformungsgrad e von mindestens 0,8 aufweisen, dass die Lösungsglühung in einer Hitze nach dem letzten Walzstich durchgeführt und das Werkstück (1) ohne weitere Zusatzbehandlung von der Lösungsglühtemperatur direkt in Wasser abgeschreckt wird, wobei die Temperatur T1 ... Tn des Werkstücks (1) mit Pyrometern (4) überwacht und alle massgebenden Betriebsgrössen von einem Steuergerät (9) über einen Regler (8) beeinflusst werden.1. A process for the production of semi-finished products from a stainless austenitic or martensitic steel, starting from a rolled raw material, the workpiece (1) being subjected to a further rolling process and a heat treatment including solution annealing and subsequent water quenching, characterized in that the last ones are heated Rolling passes performed have a degree of deformation e of at least 0.8, that the solution annealing is carried out in a heat after the last rolling pass and the workpiece (1) is quenched directly from the solution annealing temperature in water without further treatment, the temperature T 1 ... T n of the workpiece (1) is monitored with pyrometers (4) and all relevant operating variables are influenced by a control unit (9) via a controller (8). 2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass die letzten Walzstiche bei einer Temperatur durchgeführt werden, welche genügend hoch liegt, um das Werkstück (1) nach dem letzten Stich ohne zusätzliche Erwärmung aus der Lösungsglühtemperatur direkt abzuschrecken, wobei die Geschwindigkeit der Walzen (2) und die Wirkung der von einem Wasserbehälter (6) gespeisten Abschreckbrausen (7) aufeinander abgestimmt werden.2. The method according to claim 1, characterized in that the last rolling passes are carried out at a temperature which is sufficiently high to directly quench the workpiece (1) after the last pass without additional heating from the solution annealing temperature, the speed of the rolls ( 2) and the effect of the quench showers (7) fed by a water tank (6) can be coordinated. 3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass das Werkstück (1) nach dem letzten Stich in einem Durchlauf- oder Halteofen mit induktiver Heizung (5) auf eine über den Querschnitt konstante Lösungsglühtemperatur gebracht und danach in Wasser abgeschreckt wird.3. The method according to claim 1, characterized in that the workpiece (1) after the last stitch in a continuous or holding furnace with inductive heating (5) brought to a constant solution cross-section temperature and then quenched in water. 4. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass das Werkstück (1) mittels einer Walzenheizung (3) mindestens während der letzten Phase des Walzprozesses auf annähernd konstanter, der Lösungsglühung entsprechenden Temperatur gehalten und von hier aus direkt mit Wasser abgeschreckt wird.4. The method according to claim 1, characterized in that the workpiece (1) by means of a roller heater (3) at least during the last phase of the rolling process is kept at an approximately constant temperature corresponding to the solution annealing and is directly quenched with water from here.
EP84112965A 1983-11-02 1984-10-27 Method of making semi-finished products consisting of stainless austenitic or martensitic steel Withdrawn EP0144694A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3339593 1983-11-02
DE19833339593 DE3339593A1 (en) 1983-11-02 1983-11-02 METHOD FOR PRODUCING SEMI-FINISHED PRODUCTS FROM A STAINLESS STEEL AUSTENITIC OR MARTENSITICAL STEEL

Publications (2)

Publication Number Publication Date
EP0144694A2 true EP0144694A2 (en) 1985-06-19
EP0144694A3 EP0144694A3 (en) 1987-10-21

Family

ID=6213255

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84112965A Withdrawn EP0144694A3 (en) 1983-11-02 1984-10-27 Method of making semi-finished products consisting of stainless austenitic or martensitic steel

Country Status (2)

Country Link
EP (1) EP0144694A3 (en)
DE (1) DE3339593A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0352597A1 (en) * 1988-07-28 1990-01-31 Thyssen Stahl Aktiengesellschaft Process for producing hot-rolled strip or heavy plates

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1058528B (en) * 1953-02-06 1959-06-04 Alexander Schepers Dr Ing Process for maintaining the final temperature of metallic goods, such as iron, steel, etc. Like. When rolling
US3364713A (en) * 1963-08-27 1968-01-23 Yawata Iron & Steel Co Method for controlling operations for the cooling of steel plate in accordance with formulae obtained by theoretical analysis
DE1752549A1 (en) * 1967-06-15 1971-05-19 Konink Nl Hoogovens En Staalfa Method and device for cooling rolled metal strips
JPS5579826A (en) * 1978-12-08 1980-06-16 Ishikawajima Harima Heavy Ind Co Ltd Method and apparatus for hardening
JPS5741324A (en) * 1980-08-22 1982-03-08 Hitachi Ltd Manufacture of stainless steel strip
EP0060577A1 (en) * 1981-03-16 1982-09-22 BBC Brown Boveri AG Turbine blade material with high fatigue-corrosion resistance, method of production and use
US4360391A (en) * 1981-05-22 1982-11-23 Nisshin Steel Co., Ltd. Process for production of coil of hot rolled strip of austenitic stainless steel
DE3200904A1 (en) * 1982-01-14 1983-07-21 BBC Aktiengesellschaft Brown, Boveri & Cie., 5401 Baden, Aargau Process for the thermomechanical treatment of a workpiece capable of a structural transformation

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1058528B (en) * 1953-02-06 1959-06-04 Alexander Schepers Dr Ing Process for maintaining the final temperature of metallic goods, such as iron, steel, etc. Like. When rolling
US3364713A (en) * 1963-08-27 1968-01-23 Yawata Iron & Steel Co Method for controlling operations for the cooling of steel plate in accordance with formulae obtained by theoretical analysis
DE1752549A1 (en) * 1967-06-15 1971-05-19 Konink Nl Hoogovens En Staalfa Method and device for cooling rolled metal strips
JPS5579826A (en) * 1978-12-08 1980-06-16 Ishikawajima Harima Heavy Ind Co Ltd Method and apparatus for hardening
JPS5741324A (en) * 1980-08-22 1982-03-08 Hitachi Ltd Manufacture of stainless steel strip
EP0060577A1 (en) * 1981-03-16 1982-09-22 BBC Brown Boveri AG Turbine blade material with high fatigue-corrosion resistance, method of production and use
US4360391A (en) * 1981-05-22 1982-11-23 Nisshin Steel Co., Ltd. Process for production of coil of hot rolled strip of austenitic stainless steel
DE3200904A1 (en) * 1982-01-14 1983-07-21 BBC Aktiengesellschaft Brown, Boveri & Cie., 5401 Baden, Aargau Process for the thermomechanical treatment of a workpiece capable of a structural transformation

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, Band 4, Nr. 124 (C-23)[606], 2. September 1980; & JP - A - 55 79826 (ISHIKAWAJIMA HARIMA JUKOGYO) 16.06.1980 *
PATENT ABSTRACTS OF JAPAN, Band 6, Nr. 144 (C-110)[992], 25. Juni 1982; & JP - A - 57 41324 (HITACHI) 08.03.1982 *
STAHL UND EISEN, Band 85, Nr. 22, 4. November 1965, Seiten 1452-1461, D}sseldorf; A. RANDAK et al.: "W{rmebehandlung von Baust{hlen und nichtrostenden St{hlen aus der Walzhitze" *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0352597A1 (en) * 1988-07-28 1990-01-31 Thyssen Stahl Aktiengesellschaft Process for producing hot-rolled strip or heavy plates

Also Published As

Publication number Publication date
DE3339593A1 (en) 1985-05-15
EP0144694A3 (en) 1987-10-21

Similar Documents

Publication Publication Date Title
EP1469954B2 (en) Method for producing a hot rolled strip from austenitic rust-resistant steels
DE69618414T2 (en) Process for the continuous production in a line of a sheet metal strip rolled from stainless steel with an improved surface condition
DE69102280T2 (en) METHOD AND SYSTEM FOR THE PRODUCTION OF STEEL TAPE COILS DIRECTLY GENERATED FROM A HOT ROLLING MILL WITH COLD ROLLING PROPERTIES.
DE69431178T2 (en) Method and device for the thermal surface treatment of a strand
DE10256750A1 (en) Process control process control system for metal forming, cooling and / or heat treatment
EP2507399A1 (en) Hot rolling mill and method for hot rolling a metal strip or sheet
DE2315703A1 (en) METHOD FOR PRODUCING SILICON STEEL STRIP
DE1292696B (en) Process to increase the service life of roller pairs
EP1812609B1 (en) Method and device for shaping wire-shaped and rod-shaped starting materials close to finishing wire gauge
DE3033501C2 (en)
EP0144694A2 (en) Method of making semi-finished products consisting of stainless austenitic or martensitic steel
DE69319285T2 (en) Process for the heat treatment of wire rod
DE69712417T2 (en) METHOD FOR CONTINUOUSLY casting METAL SHEET
DE3339594A1 (en) Process for producing rolling material from a stainless austenitic or martensitic steel
EP3206808B1 (en) Installation and method for producing heavy plate
DE3307041A1 (en) Method and apparatus for the low-distortion series hardening of workpieces and application of the method
DE102012020844A1 (en) Process for the thermomechanical treatment of hot-rolled profiles
DE102020214427A1 (en) Method for producing a hot strip by means of a casting and rolling plant
DE2529272A1 (en) METHOD AND DEVICE FOR TREATMENT OF ROLLED WIRE
DE102006010137A1 (en) Direct strand reduction process to manufacture metal strip from hot casting block via holding oven, induction oven and mill train
DE102015114136B4 (en) Process for heat treating a metal long product
DE10234109A1 (en) Method and device for the continuous production of metallic strips
DE1583987C3 (en) Method and apparatus for heat treating hot rolled steel wire
DE3200904A1 (en) Process for the thermomechanical treatment of a workpiece capable of a structural transformation
DE2419382A1 (en) Blanking parts from cold-rolled steel strip - using electron beam for local heating of the contour to assist blanking

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE DE FR GB IT SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE DE FR GB IT SE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19880503

RIN1 Information on inventor provided before grant (corrected)

Inventor name: RYDSTAD, HANS, DR.