EP0045815B1 - Semi-finished steel article and method for producing same - Google Patents
Semi-finished steel article and method for producing same Download PDFInfo
- Publication number
- EP0045815B1 EP0045815B1 EP80104708A EP80104708A EP0045815B1 EP 0045815 B1 EP0045815 B1 EP 0045815B1 EP 80104708 A EP80104708 A EP 80104708A EP 80104708 A EP80104708 A EP 80104708A EP 0045815 B1 EP0045815 B1 EP 0045815B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- billet
- lead
- steel
- hot
- recited
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
-
- 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
- C21D7/00—Modifying the physical properties of iron or steel by deformation
- C21D7/13—Modifying the physical properties of iron or steel by deformation by hot working
Definitions
- the present invention relates generally to elongated semi-finished, free machining steel shapes and more particularly to such shapes which are free of surface cracking and to methods for producing such shapes.
- a semi-finished steel shape is a bloom or a billet, the latter having a smaller cross-section than the former, produced from an ingot or a continuously cast strand having a cross-section similar to that of a bloom or billet and which has been subjected to a hot deforming operation such as roll straightening.
- the machinability of steel is increased by adding alloying ingredients such as sulphur, lead, tellurium and bismuth.
- molten steel containing at least some of the machinability increasing ingredients described above, is poured into an ingot mould where the steel is cast into an elongated solid shape. After cooling, the ingot is reheated and subjected to a hot rolling operation which rolls the ingot into a bloom, and the bloom is then reheated and subjected to a further hot rolling operation to form the bloom into a billet. The billet is subsequently rolled into a bar, which is a finished steel shape.
- the steel is continuously cast as strands having the cross-section of a billet, the strand is subjected to a roll bending operation or a roll straightening operation while the steel is at a hot deforming temperature, and, after the roll straightening operation, the strand is cut into billet lengths (which comprise semi-finished steel shapes).
- the hot rolling of the ingot into a bloom and the hot rolling of the bloom into a billet are generally performed at a hot rolling temperature in the range 920 0- 1150 0 C (1700°-2100°F).
- the roll straightening of a continuously cast strand is generally performed at a temperature in the range 920 0- 1100°C (17000-20000 F).
- the hot rolling of the ingot into a bloom, the hot rolling of the bloom into a billet, and the roll straightening of the continuously cast strand are all hot deforming operations, and the temperature ranges described above are the typical, normal temperature ranges used for these hot deforming operations.
- tellurium When tellurium is present in a free machining steel, all the tellurium is in inclusion form, principally as lead telluride (PbTe) when lead is also present. Some of the tellurium may also be present as manganese telluride (MnTe).
- PbTe lead telluride
- MnTe manganese telluride
- attempts to combat surface cracking include reheating the unfinished steel shape without flame impingement on the surface of the unfinished shape (U.S. Patent No. 3,287,954 Scrader et al), reducing the moisture content in the atmosphere of the reheating furnace (U.S. Patent No. 3,365,922 Conces et al), removing the surface and first sub-layer of the unfinished steel shape, e.g. by scarfing, after reheating (U.S. Patent No. 3,382,700 Heitmann et al) and providing a blanket of non-oxidizing gas around the steel shapes as they undergo reheating (U.S. Patent No. 3,710,608 Hentz et al).
- the invention as claimed reduces or eliminates the above discussed problems of surface cracking.
- compositional changes have the net effect of eliminating or minimizing the formation of lead telluride.
- lead In conventional free machining steels, lead is normally present in the range 0.25-0.35 wt. % and tellurium is normally present in the range 0.04-0.06 wt. %.
- the lead content is either eliminated entirely or, if not eliminated entirely, it is reduced from 0.25-0.35 wt. % to 0.15 wt. % maximum and the tellurium is reduced from 0.04-0.06 wt. % to 0.02 wt. % maximum.
- the reduction in machinability resulting from the lower lead and tellurium contents is offset by adding bismuth in the range of 0.10-0.40 wt. %.
- the tellurium is present either as bismuth telluride (Bi 2 Te 3 ) or as manganese telluride (MnTe) which may be in the form of an eutectic with manganese sulphide (MnS).
- the hot deforming temperature should preferably be conductd within the range 920°-1035°C (1700 0- 1900 0 F). This is to offset the tendency of substantial amounts of manganese telluride to cause surface cracking during hot rolling at temperatures substantially exceeding 1035°C (1900°F), e.g. if the steel undergoes hot rolling at a temperature of about 1150°C (2100°F).
- a free machining, elongated, semi-finished steel shape devoid of surface cracking in accordance with the present invention can be produced by a method utilising two different casting procedures, either ingot casting or continuous casting. No matter which casting procedure is utilised, the steel composition may be essentially the same, within the broad limits set forth below, in weight percent:
- a machinability increasing amount of tellurium is generally about 0.02 wt. %, minimum. Up to 0.15 wt. % lead is optional.
- a bath of molten steel having a composition within the range set forth above is then cast into an elongated solid shape such as an ingot.
- the amounts of manganese and bismuth, within the ranges set forth above, are sufficient so that, when the steel is in solid form and no lead is present, all of the tellurium is combined with the manganese and/or the bismuth as micro inclusions of manganese telluride and/or bismuth telluride and the bismuth is also present as micro inclusions of elemental bismuth, there being substantially no iron telluride (FeTe) present in the solid steel.
- Iron telluride has a detrimental effect from the standpoint of causing surface cracking during hot deforming.
- the ingot After the steel has been cast into an ingot, and the ingot has cooled, the ingot is removed from the ingot mould, reheated (an operation known as soaking) and then subjected to a hot rolling operation at a hot rolling temperature in the range 920 0- 1150°C (1700 0- 2100°F) wherein the ingot is rolled into bloom.
- a hot rolling temperature in the range 920 0- 1150°C (1700 0- 2100°F) wherein the ingot is rolled into bloom.
- the resulting intermediate, hot deformed steel shape i.e. the bloom, has a surface substantially devoid of surface cracking, prior to any surface conditioning of the bloom.
- the bloom is then reheated and hot rolled at a temperature in the range 920 0- 1150 0 C (1700 0- 2100 0 F) to produce a billet having a surface substantially free of surface cracking prior to any surface conditioning thereof, and there is no need to conduct a surface removal step between the bloom reheating step and the step of hot rolling the bloom into a billet.
- the surface of the bloom or billet devoid of substantial surface cracking, but, also the surface is devoid of burning in the as-deformed condition, due to the fact that the steel shape is rolled at a temperature (1150°C maximum) (2100°F maximum), below that at which burning of the steel occurs.
- the steps comprise continuously casting molten steel (having a composition within the ranges set forth above) into a strand and then roll straightening the strand while the latter is at a temperature in the range 920°-1 100°C (17000-2000°F).
- the strand which already has the cross-section of a billet, is then cut into the usual billet lengths.
- the roll straightening step which the strand undergoes at the temperature range described above is tantamount to a hot deforming step, but the surface of the strand, and of the billets which are cut from the strand, are devoid of surface cracking and burning in the as-deformed condition.
- a billet formed from either of the above described manufacturing procedures has an oxide on its surface in the billet's as-deformed condition. This is reflective of the fact that the billet has not undergone any surface conditioning.
- as-deformed condition refers to the condition of the billet immediately after being hot rolled (or otherwise hot deformed) and before it undergoes any surface conditioning following the hot deforming step.
- Surface conditioning is a procedure conventionally utilised to remove surface imperfections or portions from semi-finished steel articles after a hot deforming step and includes grinding, chipping, scarfing, planing and the like.
- the combined lead plus bismuth content of the steel shape should be at least 0.25 wt. % to supply the desired machinability. Therefore, in that embodiment of the invention wherein lead is ; completely absent, the bismuth content should be at least 0.25 wt. %. In that embodiment of the invention wherein lead is present up to 0.15 wt. %, the bismuth may be less than 0.25 wt. % so long as the combined lead and bismuth content is 0.25 wt. % minimum.
- the present invention may be applied to virtually all steel base compositions to which lead and tellurium have previously been added. Examples thereof are set forth in Holowaty U.S. Patent No. 3,152,889, and the disclosure therein is incorporated herein by reference. Examples of steel compositions in accordance with the present invention are contained in the table set forth below.
- the balance of the composition consists essentially of iron (plus the usual incidentals/impurities).
- the present invention may be applied to plan carbon steels having a base composition (i.e. a composition without lead, tellurium or bismuth) in the 1000 series, 1100 series or 1200 series of steels (AISI numbers) in which the lead, tellurium and bismuth contents are controlled as described above and which, in their solidified form, are subjected to hot deforming procedures (including hot deforming temperatures) as described above.
- a base composition i.e. a composition without lead, tellurium or bismuth
- AISI numbers 1100 series or 1200 series of steels
- the present invention may also be applied to certain alloy steels to which lead and tellurium have heretofore been added, such as steels having compositions corresponding to AISI steels 4140, 4142 and 8620.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Description
- The present invention relates generally to elongated semi-finished, free machining steel shapes and more particularly to such shapes which are free of surface cracking and to methods for producing such shapes.
- A semi-finished steel shape is a bloom or a billet, the latter having a smaller cross-section than the former, produced from an ingot or a continuously cast strand having a cross-section similar to that of a bloom or billet and which has been subjected to a hot deforming operation such as roll straightening.
- The machinability of steel is increased by adding alloying ingredients such as sulphur, lead, tellurium and bismuth.
- In one type of manufacturing operation for producing a semi-finished steel shape having a free machining composition, molten steel, containing at least some of the machinability increasing ingredients described above, is poured into an ingot mould where the steel is cast into an elongated solid shape. After cooling, the ingot is reheated and subjected to a hot rolling operation which rolls the ingot into a bloom, and the bloom is then reheated and subjected to a further hot rolling operation to form the bloom into a billet. The billet is subsequently rolled into a bar, which is a finished steel shape.
- In another form of manufacturing operation, for producing a semi-finished steel shape having a free machining composition, the steel is continuously cast as strands having the cross-section of a billet, the strand is subjected to a roll bending operation or a roll straightening operation while the steel is at a hot deforming temperature, and, after the roll straightening operation, the strand is cut into billet lengths (which comprise semi-finished steel shapes).
- The hot rolling of the ingot into a bloom and the hot rolling of the bloom into a billet are generally performed at a hot rolling temperature in the range 9200-11500C (1700°-2100°F). The roll straightening of a continuously cast strand is generally performed at a temperature in the range 9200-1100°C (17000-20000 F). The hot rolling of the ingot into a bloom, the hot rolling of the bloom into a billet, and the roll straightening of the continuously cast strand are all hot deforming operations, and the temperature ranges described above are the typical, normal temperature ranges used for these hot deforming operations.
- When tellurium is present in a free machining steel, all the tellurium is in inclusion form, principally as lead telluride (PbTe) when lead is also present. Some of the tellurium may also be present as manganese telluride (MnTe).
- In steels containing lead and tellurium, and undesirable phenomenon occurs at the temperature range normally utilised for hot deforming. This phenomenon, known as surface cracking or surface checking or surface tearing, is manifest by a large number of small cracks or checks at the surface of the semi-finished steel shape, particularly along the corners. Severe surface checking renders a steel shape commercially unacceptable.
- Surface cracking has been recognised in the prior art and attempts to combat this phenomenon have -also been described in the prior art. More specifically, attempts to combat surface cracking include reheating the unfinished steel shape without flame impingement on the surface of the unfinished shape (U.S. Patent No. 3,287,954 Scrader et al), reducing the moisture content in the atmosphere of the reheating furnace (U.S. Patent No. 3,365,922 Conces et al), removing the surface and first sub-layer of the unfinished steel shape, e.g. by scarfing, after reheating (U.S. Patent No. 3,382,700 Heitmann et al) and providing a blanket of non-oxidizing gas around the steel shapes as they undergo reheating (U.S. Patent No. 3,710,608 Hentz et al).
- Typical examples of steel containing both lead and tellurium are disclosed in Holowaty U.S. Patent No. 3,152,889.
- In accordance with one aspect of the present invention we provide a method for producing a free-machining, elongated, semi-finished, tellurium containing steel shape devoid of surface cracking, prior to any surface conditioning thereof, due to lead telluride, characterised in that said method comprises the steps of:
- providing a bath of molten steel having a composition comprising, in wt. %:
- casting said molten steel into an elongated solid shape;
- said steel being provided with sufficient manganese and bismuth so that, in said solid shape, all of the tellurium is combined with said manganese and/or said bismuth as micro-inclusions of MnTe and/or Bi2Te3 (except that when lead is present some of the tellurium may be combined with lead as micro-inclusions of PbTe in amounts insufficient to produce substantial surface cracking during hot forming of said billet) and said bismuth is also present as micro-inclusions of elemental bismuth, there being substantially no FeTe present in said solid shape;
- heating said elongated steel shape to a hot deforming temperature, without burning the steel shape;
- and hot deforming said elongated shape while the latter is at a temperature above about 920°C (1700°F) and below 1150°C (2100°F).
- In accordance with another aspect of the invention, we provide an as-deformed billet of free machining steel characterised in that said billet comprises:
- a composition comprising, in wt. %:
- all of said tellurium being combined with said manganese and/or said bismuth as micro inclusions of MnTe and/or Bi2Te3 (except that when lead is present some of the tellurium may be combined with lead as microinclusions of PbTe in amounts insufficient to produce substantial surface cracking during hot forming of said billet)
- there being substantially no FeTe;
- micro inclusions of elemental bismuth;
- a billet surface substantially devoid of surface cracking and burning in the as-deformed condition; and iron oxide on the surface of said billet in said as-deformed condition.
- The invention as claimed reduces or eliminates the above discussed problems of surface cracking.
- In accordance with the present invention, it has been determined that, if the amount of lead telluride in the microstructure of the steel is substantially reduced, then the extent to which the steel undergoes surface cracking during hot deforming is also substantialiy reduced, if not entirely eliminated. However, to reduce the amount of lead telluride present requires a substantial reduction of either the lead content or the tellurium content or both, and this reduces the machinability of the steel which would be undesirable.
- It has been determined that the susceptibility of the steel to surface cracking can be substantially minimised without reducing the machinability of the steel by completely replacing the lead with bismuth or by
- (1) replacing a substantial part of the lead with bismuth; and
- (2) substantially reducing the tellurium content of the steel.
- These compositional changes have the net effect of eliminating or minimizing the formation of lead telluride.
- In conventional free machining steels, lead is normally present in the range 0.25-0.35 wt. % and tellurium is normally present in the range 0.04-0.06 wt. %. In accordance with the present invention, the lead content is either eliminated entirely or, if not eliminated entirely, it is reduced from 0.25-0.35 wt. % to 0.15 wt. % maximum and the tellurium is reduced from 0.04-0.06 wt. % to 0.02 wt. % maximum. The reduction in machinability resulting from the lower lead and tellurium contents is offset by adding bismuth in the range of 0.10-0.40 wt. %.
- In the absence of lead, instead of forming lead telluride, the tellurium is present either as bismuth telluride (Bi2Te3) or as manganese telluride (MnTe) which may be in the form of an eutectic with manganese sulphide (MnS). Where substantial amounts of manganese telluride are present in the microstructure of the steel (e.g. in the absence of lead), the hot deforming temperature should preferably be conductd within the range 920°-1035°C (17000-19000F). This is to offset the tendency of substantial amounts of manganese telluride to cause surface cracking during hot rolling at temperatures substantially exceeding 1035°C (1900°F), e.g. if the steel undergoes hot rolling at a temperature of about 1150°C (2100°F).
- Other features and advantages are inherent in the subject matter claimed and disclosed or will become apparent to those skilled in the art from the following detailed description.
- Embodiments of the invention will now be described in detail by way of example.
- A free machining, elongated, semi-finished steel shape devoid of surface cracking in accordance with the present invention can be produced by a method utilising two different casting procedures, either ingot casting or continuous casting. No matter which casting procedure is utilised, the steel composition may be essentially the same, within the broad limits set forth below, in weight percent:
- A machinability increasing amount of tellurium is generally about 0.02 wt. %, minimum. Up to 0.15 wt. % lead is optional.
- A bath of molten steel having a composition within the range set forth above is then cast into an elongated solid shape such as an ingot. The amounts of manganese and bismuth, within the ranges set forth above, are sufficient so that, when the steel is in solid form and no lead is present, all of the tellurium is combined with the manganese and/or the bismuth as micro inclusions of manganese telluride and/or bismuth telluride and the bismuth is also present as micro inclusions of elemental bismuth, there being substantially no iron telluride (FeTe) present in the solid steel. Iron telluride has a detrimental effect from the standpoint of causing surface cracking during hot deforming.
- After the steel has been cast into an ingot, and the ingot has cooled, the ingot is removed from the ingot mould, reheated (an operation known as soaking) and then subjected to a hot rolling operation at a hot rolling temperature in the range 9200-1150°C (17000-2100°F) wherein the ingot is rolled into bloom. The resulting intermediate, hot deformed steel shape, i.e. the bloom, has a surface substantially devoid of surface cracking, prior to any surface conditioning of the bloom. The bloom is then reheated and hot rolled at a temperature in the range 9200-11500C (17000-21000F) to produce a billet having a surface substantially free of surface cracking prior to any surface conditioning thereof, and there is no need to conduct a surface removal step between the bloom reheating step and the step of hot rolling the bloom into a billet.
- Not only is the surface of the bloom or billet devoid of substantial surface cracking, but, also the surface is devoid of burning in the as-deformed condition, due to the fact that the steel shape is rolled at a temperature (1150°C maximum) (2100°F maximum), below that at which burning of the steel occurs.
- In a manufacturing procedure wherein the billet is formed by a continuous casting operation, the steps comprise continuously casting molten steel (having a composition within the ranges set forth above) into a strand and then roll straightening the strand while the latter is at a temperature in the range 920°-1 100°C (17000-2000°F). The strand, which already has the cross-section of a billet, is then cut into the usual billet lengths.
- The roll straightening step which the strand undergoes at the temperature range described above is tantamount to a hot deforming step, but the surface of the strand, and of the billets which are cut from the strand, are devoid of surface cracking and burning in the as-deformed condition.
- A billet formed from either of the above described manufacturing procedures has an oxide on its surface in the billet's as-deformed condition. This is reflective of the fact that the billet has not undergone any surface conditioning. As used herein, the term "as-deformed condition" refers to the condition of the billet immediately after being hot rolled (or otherwise hot deformed) and before it undergoes any surface conditioning following the hot deforming step.
- Surface conditioning is a procedure conventionally utilised to remove surface imperfections or portions from semi-finished steel articles after a hot deforming step and includes grinding, chipping, scarfing, planing and the like.
- The combined lead plus bismuth content of the steel shape should be at least 0.25 wt. % to supply the desired machinability. Therefore, in that embodiment of the invention wherein lead is ; completely absent, the bismuth content should be at least 0.25 wt. %. In that embodiment of the invention wherein lead is present up to 0.15 wt. %, the bismuth may be less than 0.25 wt. % so long as the combined lead and bismuth content is 0.25 wt. % minimum.
- In that embodiment of the invention in which some lead is added to the steel (up to 0.15 wt. % maximum), although there may be small amounts of lead tellurium micro inclusions in the steel, these amounts are insufficient to produce substantial surface cracking during the hot deforming step. This is because not only is the lead content limited to 0.15 wt. % maximum, in this embodiment, but also, the tellurium content is limited to 0.02 wt.% maximum.
- The present invention may be applied to virtually all steel base compositions to which lead and tellurium have previously been added. Examples thereof are set forth in Holowaty U.S. Patent No. 3,152,889, and the disclosure therein is incorporated herein by reference. Examples of steel compositions in accordance with the present invention are contained in the table set forth below.
- In all of the above steels A-D, the balance of the composition consists essentially of iron (plus the usual incidentals/impurities).
- Generally speaking, the present invention may be applied to plan carbon steels having a base composition (i.e. a composition without lead, tellurium or bismuth) in the 1000 series, 1100 series or 1200 series of steels (AISI numbers) in which the lead, tellurium and bismuth contents are controlled as described above and which, in their solidified form, are subjected to hot deforming procedures (including hot deforming temperatures) as described above.
- The present invention may also be applied to certain alloy steels to which lead and tellurium have heretofore been added, such as steels having compositions corresponding to AISI steels 4140, 4142 and 8620.
- The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.
Claims (11)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE8080104708T DE3068522D1 (en) | 1980-08-11 | 1980-08-11 | Semi-finished steel article and method for producing same |
EP80104708A EP0045815B1 (en) | 1980-08-11 | 1980-08-11 | Semi-finished steel article and method for producing same |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP80104708A EP0045815B1 (en) | 1980-08-11 | 1980-08-11 | Semi-finished steel article and method for producing same |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0045815A1 EP0045815A1 (en) | 1982-02-17 |
EP0045815B1 true EP0045815B1 (en) | 1984-07-11 |
Family
ID=8186750
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP80104708A Expired EP0045815B1 (en) | 1980-08-11 | 1980-08-11 | Semi-finished steel article and method for producing same |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0045815B1 (en) |
DE (1) | DE3068522D1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4741786A (en) * | 1986-06-10 | 1988-05-03 | Stanadyne, Inc. | Cold drawn free-machining steel bar including bismuth |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2937908A1 (en) * | 1978-09-20 | 1980-04-03 | Daido Steel Co Ltd | TE-S AUTOMATIC STEEL WITH LOW ANISOTROPY AND METHOD FOR THE PRODUCTION THEREOF |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2378548A (en) * | 1944-01-11 | 1945-06-19 | Bethlehem Steel Corp | Ferrous alloys containing bismuth |
DE1222269B (en) * | 1958-04-01 | 1966-08-04 | Inland Steel Co | Free cutting steel |
US3152889A (en) * | 1961-10-31 | 1964-10-13 | Inland Steel Co | Free machining steel with lead and tellurium |
US3287954A (en) * | 1962-08-30 | 1966-11-29 | Inland Steel Co | Method for heating steel billets |
US3152890A (en) * | 1963-11-14 | 1964-10-13 | Inland Steel Co | Free machining steel with sulphur plus tellurium and/or selenium |
US3365922A (en) * | 1965-02-01 | 1968-01-30 | Inland Steel Co | Method for producing hot-worked tellurium-containing steel article |
US3382700A (en) * | 1966-03-31 | 1968-05-14 | Inland Steel Co | Process for reducing surface checking during hot working of steel |
US3590476A (en) * | 1969-02-27 | 1971-07-06 | Inland Steel Co | Method for producing a tellurium steel article |
FR2088015B1 (en) * | 1970-05-08 | 1974-08-09 | Creusot Loire | |
FR2105701A5 (en) * | 1970-09-17 | 1972-04-28 | Pompey Acieries | |
US3710608A (en) * | 1970-12-02 | 1973-01-16 | Inland Steel Co | Method for heating unfinished tellurium-containing steel articles before hot rolling |
DE2107525A1 (en) * | 1971-02-17 | 1972-08-24 | Schwaebische Huettenwerke Gmbh | Hollow composite chilled iron roll - having core of automat steel |
-
1980
- 1980-08-11 EP EP80104708A patent/EP0045815B1/en not_active Expired
- 1980-08-11 DE DE8080104708T patent/DE3068522D1/en not_active Expired
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2937908A1 (en) * | 1978-09-20 | 1980-04-03 | Daido Steel Co Ltd | TE-S AUTOMATIC STEEL WITH LOW ANISOTROPY AND METHOD FOR THE PRODUCTION THEREOF |
Also Published As
Publication number | Publication date |
---|---|
EP0045815A1 (en) | 1982-02-17 |
DE3068522D1 (en) | 1984-08-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4067754A (en) | Cold rolled, ductile, high strength steel strip and sheet and method therefor | |
KR950004936B1 (en) | Fe-ni alloy sheet for shadow mask excellent in etching pierce ability preventing sticking during annealing and inhibiting production of gases | |
US2768915A (en) | Ferritic alloys and methods of making and fabricating same | |
US4236939A (en) | Semi-finished steel article and method for producing same | |
US4333776A (en) | Semi-finished steel article | |
EP0045815B1 (en) | Semi-finished steel article and method for producing same | |
JP2905243B2 (en) | Manufacturing method of bearing material with excellent rolling fatigue life | |
EP0587150A1 (en) | Process for hot working continuous-cast bloom and steel ingot | |
US3753788A (en) | Non-ribbing ferritic steel and process | |
JP2843665B2 (en) | Hot work crack prevention method for continuous cast slab. | |
KR100306138B1 (en) | METHOD FOR MANUFACTURING Bi-S FREE CUTTING STEEL ROD WIRE WITH NO SURFACE DEFECTS | |
KR950009168B1 (en) | Making method of non-heat-treatment steel with hot forging | |
JP3091795B2 (en) | Manufacturing method of steel bars with excellent drawability | |
JPS5925025B2 (en) | Roll material with excellent wear resistance and breakage resistance | |
KR100225448B1 (en) | The manufacturing method of fe-ni alloy sheet for shadow mask | |
JP2746059B2 (en) | Roll for hot rolling | |
KR100285651B1 (en) | Method for manufacturing bismuth-sulfur free cutting steel wire rods with beautiful appearance | |
USRE31221E (en) | Cold rolled, ductile, high strength steel strip and sheet and method therefor | |
JP3091794B2 (en) | Method of manufacturing automotive shaft parts excellent in extrudability and forgeability | |
JPS59177352A (en) | Low-decarburization spring steel for continuous casting | |
USRE31306E (en) | Cold rolled, ductile, high strength steel strip and sheet and method therefor | |
JPS5843464B2 (en) | High carbon chromium nickel steel with excellent hot workability | |
JPH0229725B2 (en) | KOJINSEINETSUKANTANZOYOHICHOSHITSUBOKONOSEIZOHOHO | |
JP2862607B2 (en) | Manufacturing method of steel with excellent drilling workability | |
KR100381525B1 (en) | Austenitic stainless steel with excellent rolling properties and manufacturing method |
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 |
|
17P | Request for examination filed |
Effective date: 19811019 |
|
AK | Designated contracting states |
Designated state(s): BE CH DE FR GB IT NL |
|
ITF | It: translation for a ep patent filed |
Owner name: JACOBACCI & PERANI S.P.A. |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Designated state(s): BE CH DE FR GB IT LI NL |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 19840725 Year of fee payment: 5 Ref country code: CH Payment date: 19840725 Year of fee payment: 5 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 19840731 Year of fee payment: 5 |
|
REF | Corresponds to: |
Ref document number: 3068522 Country of ref document: DE Date of ref document: 19840816 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 19840930 Year of fee payment: 5 |
|
ET | Fr: translation filed | ||
PLBI | Opposition filed |
Free format text: ORIGINAL CODE: 0009260 |
|
26 | Opposition filed |
Opponent name: THYSSEN STAHL AG Effective date: 19850404 |
|
NLR1 | Nl: opposition has been filed with the epo |
Opponent name: THYSSEN STAHL AG |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 19870831 Year of fee payment: 8 |
|
RDAG | Patent revoked |
Free format text: ORIGINAL CODE: 0009271 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: PATENT REVOKED |
|
GBPR | Gb: patent revoked under art. 102 of the ep convention designating the uk as contracting state | ||
27W | Patent revoked |
Effective date: 19880619 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
NLR2 | Nl: decision of opposition | ||
BERE | Be: lapsed |
Owner name: INLAND STEEL CY Effective date: 19880831 |
|
APAH | Appeal reference modified |
Free format text: ORIGINAL CODE: EPIDOSCREFNO |