US3926689A - Method of producing hot rolled steel rods or bars - Google Patents

Method of producing hot rolled steel rods or bars Download PDF

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Publication number
US3926689A
US3926689A US411227A US41122773A US3926689A US 3926689 A US3926689 A US 3926689A US 411227 A US411227 A US 411227A US 41122773 A US41122773 A US 41122773A US 3926689 A US3926689 A US 3926689A
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US
United States
Prior art keywords
bar
rod
core
surface layer
quenching
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.)
Expired - Lifetime
Application number
US411227A
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English (en)
Inventor
Yves Jean Respen
Paul Andre Cosse
Mario Economopoulos
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.)
Centre de Recherches Metallurgiques CRM ASBL
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Centre de Recherches Metallurgiques CRM ASBL
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.)
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Publication date
Application filed by Centre de Recherches Metallurgiques CRM ASBL filed Critical Centre de Recherches Metallurgiques CRM ASBL
Priority to US05/617,156 priority Critical patent/US4016015A/en
Application granted granted Critical
Publication of US3926689A publication Critical patent/US3926689A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/02—Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation
    • 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 of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
    • C21D8/06—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite
    • 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
    • C21D2221/00—Treating localised areas of an article
    • C21D2221/10—Differential treatment of inner with respect to outer regions, e.g. core and periphery, respectively

Definitions

  • the present invention relates to a treatment for improving the quality of a rolled steel rod or bar and especially a concrete-reinforcing rod or bar.
  • the process can be applied to both killed and semikilled steels and rimming steels.
  • the main qualities looked for in a steel rod or bar are, inter alia, as high as possible a yield point for the grade of steel, used as well as weldability, fatigue resistance, and sufficient ductility for the intended use.
  • the steel can be subjected to a suitable cooling treatment, preferably applied directly at the exit of the rolling mill, which enables the yield point of the rod or bar to be raised to some extent.
  • the present invention provides a process for the production of a steel rod or bar in a hot rolling mill, including superficially quenching the rod or bar at the exit of the finishing stand, with the core of the rod or bar having a temperature of approximately 850C at the end of the quenching step.
  • the invention provides a process for the production of a, steel rod or bar in a hot rolling mill, including: superficially quenching the rod or bar at the exit of the finishing stand, to give the surface layer of the rod or bar a bainitic or martensitic structure, with the core of the rod or bar remaining austenitic and subsequently cooling the rod or bar at such a rate that the austenitic core transforms to ferrite and carbides.
  • the rod or bar is subjected to superficial quenching by means of a suitable cooling liquid, and the conditions of quenching are selected so that at the outlet of the liquid-cooling zone, the core of the rod or bar has a temperature of about 850C (e.g. 800860C).
  • the rod or bar stays on the cooler (air cooling), so that it is possible for the quenched surface layer to become tempered and for the austenitic core of the rod or bar to transform to ferrite and carbides (e.g. to transform to pearlite).
  • the quenched surface layer is either of martensite or bainite.
  • the desired quenching of the bar is obtained by selecting the cooling devices and suitably adjusting the length and arrangement of these devices, for example cooling sprays.
  • the steel may have an yield point of 45 kg/mm when the installation has a low heat transfer coefficient, and may have an yield point of 65 kg/mm if this coefficient is raised, if, for example, a short cooling spray is used but where very intense cooling of the rod or bar has taken place (e.g., if the water contains a mineral salt or a surface-active agent in suspension or solution).
  • the example just given allows the improvement in the quality of the rod or bar obtained by implementing the process of the invention to be appreciated.
  • the rolled test-pieces examined were concrete-reinforcing bars 12 mm in diameter and of steel having the following composition:
  • the process according to the invention enables rod and bar of a particular type to be obtained, namely having a bainitic or martensitic surface layer and a core composed of ferrite and carbides.
  • FIG. 1 shows the variation of the hardness of the steel along a radius of a cross-section of a concrete-reinforcing bar as treated according to the invention.
  • the hardness (DI-IP) is shown along the ordinate while the abscissa indicates the distance (d) from the surface of the bar.
  • FIG. 2a illustratesa cross-section of a concrete-reinforcing bar treated according to the invention in which the surface layer and core can be distinctly seen.
  • FIG. 2b shows the martensitic surface layer, and
  • FIG. shows the ferrite and carbides which constitute the core of the bar (magnification: 500 x).
  • a process for the production of a steel rod or bar in a hot rolling mill comprising: superficially quenching the rod or bar at the exit of a finishing stand to form bainite or martensite in the surface layer of the rod or 2.
  • a process for the production of a steel rod or bar in a hot rolling mill including: superficially quenching the rod or bar at the exit of a finishing stand, to give the surface layer of the rod or bar a bainitic or martensitic structure, with the core of the rod or bar remaining austenitic; and subsequently cooling the rod or bar at such a rate that the austenitic core transforms to ferrite and carbides.
  • a process for the production of a steel rod or bar in ahot rolling mill comprising: superficially quenching the rod or bar at the exit of a finishing stand, to transform austenite in the surface layer of the rod or bar to bainite or martensite, with the core of the rod or bar remaining austenite; and subsequently cooling the rod or bar at such a rate that the core of austenite transforms to ferrite and carbides while the surface layer is tempered by the heat transferred from the core.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)
  • Heat Treatment Of Articles (AREA)
US411227A 1972-10-31 1973-10-31 Method of producing hot rolled steel rods or bars Expired - Lifetime US3926689A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US05/617,156 US4016015A (en) 1972-10-31 1975-09-26 Rolled steel rod or bar

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
BE790867 1972-10-31

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US05/617,156 Division US4016015A (en) 1972-10-31 1975-09-26 Rolled steel rod or bar

Publications (1)

Publication Number Publication Date
US3926689A true US3926689A (en) 1975-12-16

Family

ID=3860370

Family Applications (1)

Application Number Title Priority Date Filing Date
US411227A Expired - Lifetime US3926689A (en) 1972-10-31 1973-10-31 Method of producing hot rolled steel rods or bars

Country Status (9)

Country Link
US (1) US3926689A (2)
JP (1) JPS49134513A (2)
BE (1) BE790867A (2)
FR (1) FR2204693B1 (2)
GB (1) GB1392269A (2)
IT (1) IT1004614B (2)
LU (1) LU68624A1 (2)
MY (1) MY8800139A (2)
NL (1) NL168001C (2)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2844331A1 (de) * 1977-10-14 1979-04-19 Centre Rech Metallurgique Verfahren zur behandlung rohrfoermiger stahlprofile
US4175985A (en) * 1977-05-13 1979-11-27 Centre De Recherches Metallurgiques-Centrum Voor Research In De Metallurgie Method of producing steel sections of improved quality
US4242153A (en) * 1978-10-16 1980-12-30 Morgan Construction Company Methods for hot rolling and treating rod
US4298406A (en) * 1977-11-03 1981-11-03 British Steel Corporation Manufacture of steel products
EP0140592A3 (en) * 1983-10-31 1985-09-25 Morgan Construction Company Method and apparatus for cooling steel rod
US6330903B1 (en) * 1997-02-05 2001-12-18 Steve Weinreich Mechanism for constant balance with method for manufacture of variable pitch screw
US20090320263A1 (en) * 2008-06-26 2009-12-31 Richard Gerard Potje Methods and systems for manufacturing an axle

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL170159C (nl) * 1973-06-04 1982-10-01 Estel Hoogovens Bv Werkwijze voor het vervaardigen van lasbaar staafmateriaal uit laag koolstofstaal door gecontroleerde koeling.
DD106661A1 (2) * 1973-09-24 1974-06-20
BE839080A (fr) * 1976-03-01 1976-07-01 Procede de fabrication de barres d'armature
DE2620377A1 (de) * 1976-05-08 1977-11-17 Aeg Elotherm Gmbh Verfahren zur waermebehandlung von dickwandigen stahlroehren
US4146411A (en) 1978-01-09 1979-03-27 British Steel Corporation Hot bar cooling
DE2900271C2 (de) * 1979-01-05 1984-01-26 Stahlwerke Peine-Salzgitter Ag, 3150 Peine Schweißbarer Betonstahl und Verfahren zu seiner Herstellung
DE3431008C2 (de) * 1984-08-23 1986-10-16 Dyckerhoff & Widmann AG, 8000 München Wärmebehandlung von warmgewalzten Stäben oder Drähten
CA1265421A (en) * 1985-10-31 1990-02-06 Norio Anzawa Method and apparatus for cooling rolled steels
US4824492A (en) * 1987-12-23 1989-04-25 Chaparral Steel Company Method for producing a precipitation hardenable martensitic low alloy steel forging
DD268258A1 (de) * 1988-01-08 1989-05-24 Florin Stahl Walzwerk Hoeherfester stahl, insbesondere betonstahl bzw. ziehereivormaterial, mit verbesserten werkstoffeigenschaften und besserer verarbeitbarkeit
BE1005964A6 (fr) * 1992-06-29 1994-04-05 Centre Rech Metallurgique Procede de protection d'un produit siderurgique lamine a chaud.

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3111436A (en) * 1961-01-17 1963-11-19 Mills James Ltd Method of hardening plain carbon and low alloy steels
US3756870A (en) * 1971-05-10 1973-09-04 Park Ohio Industries Inc Induction heating method of case hardening carbon steel rod

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE762838A (fr) * 1971-02-11 1971-08-11 Centre Rech Metallurgique Procede et dispositif pour la fabrication de ronds a beton,

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3111436A (en) * 1961-01-17 1963-11-19 Mills James Ltd Method of hardening plain carbon and low alloy steels
US3756870A (en) * 1971-05-10 1973-09-04 Park Ohio Industries Inc Induction heating method of case hardening carbon steel rod

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4175985A (en) * 1977-05-13 1979-11-27 Centre De Recherches Metallurgiques-Centrum Voor Research In De Metallurgie Method of producing steel sections of improved quality
DE2844331A1 (de) * 1977-10-14 1979-04-19 Centre Rech Metallurgique Verfahren zur behandlung rohrfoermiger stahlprofile
US4204892A (en) * 1977-10-14 1980-05-27 Centre De Recherches Metallurgiques Centrum Voor Research In De Metallurgie Heat-treating tubular steel sections
US4298406A (en) * 1977-11-03 1981-11-03 British Steel Corporation Manufacture of steel products
US4242153A (en) * 1978-10-16 1980-12-30 Morgan Construction Company Methods for hot rolling and treating rod
EP0140592A3 (en) * 1983-10-31 1985-09-25 Morgan Construction Company Method and apparatus for cooling steel rod
US6330903B1 (en) * 1997-02-05 2001-12-18 Steve Weinreich Mechanism for constant balance with method for manufacture of variable pitch screw
US20090320263A1 (en) * 2008-06-26 2009-12-31 Richard Gerard Potje Methods and systems for manufacturing an axle
US8122580B2 (en) 2008-06-26 2012-02-28 American Railcar Industries, Inc. Methods for manufacturing an axle

Also Published As

Publication number Publication date
GB1392269A (en) 1975-04-30
LU68624A1 (2) 1973-12-27
FR2204693B1 (2) 1976-06-18
IT1004614B (it) 1976-07-20
NL7314593A (2) 1974-05-02
NL168001B (nl) 1981-09-16
FR2204693A1 (2) 1974-05-24
JPS49134513A (2) 1974-12-25
BE790867A (fr) 1973-02-15
NL168001C (nl) 1982-02-16
MY8800139A (en) 1988-12-31

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