GB2075390A - Method of producing rolled steel - Google Patents
Method of producing rolled steel Download PDFInfo
- Publication number
- GB2075390A GB2075390A GB8112955A GB8112955A GB2075390A GB 2075390 A GB2075390 A GB 2075390A GB 8112955 A GB8112955 A GB 8112955A GB 8112955 A GB8112955 A GB 8112955A GB 2075390 A GB2075390 A GB 2075390A
- Authority
- GB
- United Kingdom
- Prior art keywords
- steel
- rolling
- temperature
- rolled
- passes
- 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.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 76
- 239000010959 steel Substances 0.000 title claims abstract description 76
- 238000000034 method Methods 0.000 title claims description 25
- 238000005096 rolling process Methods 0.000 claims abstract description 43
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 25
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000010955 niobium Substances 0.000 claims abstract description 12
- 239000011572 manganese Substances 0.000 claims abstract description 9
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 8
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims abstract description 8
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims abstract description 5
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 5
- 239000004411 aluminium Substances 0.000 claims abstract description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 5
- 230000014509 gene expression Effects 0.000 claims abstract description 5
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 5
- 230000009467 reduction Effects 0.000 claims abstract description 5
- 230000001105 regulatory effect Effects 0.000 claims abstract description 5
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000010703 silicon Substances 0.000 claims abstract description 4
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 4
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims abstract description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 10
- 229910052759 nickel Inorganic materials 0.000 claims description 6
- 238000001953 recrystallisation Methods 0.000 claims description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 2
- 229910052750 molybdenum Inorganic materials 0.000 claims description 2
- 239000011733 molybdenum Substances 0.000 claims description 2
- 230000009466 transformation Effects 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 2
- 238000002474 experimental method Methods 0.000 description 31
- 239000000047 product Substances 0.000 description 31
- 230000007704 transition Effects 0.000 description 18
- 238000001816 cooling Methods 0.000 description 12
- 239000000203 mixture Substances 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 230000000930 thermomechanical effect Effects 0.000 description 5
- 238000005496 tempering Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 3
- 238000000137 annealing Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000005275 alloying Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052729 chemical element Inorganic materials 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000011265 semifinished product Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
- B21B3/02—Rolling special iron alloys, e.g. stainless steel
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
To produce a rolled steel product such as rolled steel bars for reinforcing concrete, steel containing carbon, manganese, silicon, aluminium and niobium is rolled in at least three passes. The total reduction during the three passes or the last three passes as the case may be is at least 20%. The temperature before, during and after rolling is regulated such that the elasticity limit and resilience at -120 DEG C of the rolled product (as calculated from the expressions: LE=1035+510C+192Mn+2270Nb-0.21T1-0.40T2-0.48T3-3.51D KCV=2202-2066C+23.20Mn-2064Nb-0.77T1-1.24T2-0.23T3-1.98D wherein C is the carbon content of the steel, Mn is the manganese content of the steel, Nb is the niobium content, if any, of the steel, T1 is the temperature of the steel before rolling, T2 is the temperature of the steel during rolling, T3 is the temperature of the steel after rolling, D is the diameter of the steel after rolling, LE is the elasticity limit, and KCV is the resilience at -120 DEG C) attain the desired high values.
Description
SPECIFICATION
Method of producing rolled steel
This invention relates to a method of producing rolled steel, more particularly rolled steel in the form of round bars for reinforcing concrete, having a good weldability, a high elasticity limit and resilience at very low temperatures.
It is known that currently-produced concrete-reinforcing bars having an elasticity limit in the region of 400 N/mm2 are not very tenacious. Thus, their transition temperature, in a Charpy V resilience test at 35 J/cm2, is in the region of 200 C. It follows from this that these bars offer only a slight resistance to rupture at low temperatures.
In the past, resilience, as determined by a Charpy V resilience test at 35 J/cm2, at a temperature in the region of 960C was not necessary, in view of the common uses of rolled steel such as concretereinforcing bars. However, recent developments, in particular developments in the storage of liquified gases, has resulted in the need for large quantities of rolled steel resistant to severe cold. Thus for example, liquified gas storage reservoirs, for reasons of safety, have to be provided with a concrete casing which is reinforced in a manner analogous to the casings for nuclear reactors.
In order to be usable to reinforce such liquified gas reservoir casings (which are exposed to temperatures from -500C to -1 960C), the concrete-reinforcing bars must have an adequate resilience at the core, and a satisfactory weldability (which implies a carbon content of less than 0.2%). Now, known concrete-reinforcing bars which have a carbon content of 0.160.2% are subjected to cold twisting which, on the one hand, has the effect of providing them with a satisfactory elasticity limit, but which, on the other hand, produces a low tenacity, particularly at low temperatures.
Attempts have been made to subject concrete-reinforcing bars having a maximum carbon content of 0.20% to intense surface cooling whilst they leave the rolling mill, and also to subsequent selftempering. By this process it is possible to obtain concrete-reinforcing bars which are weldable and tenacious. However, they do not have a transition temperature, in a Charpy V test at 35 J/cm2, significantly better than -500C.
Until now, only concrete-reinforcing bars which have been produced from steel alloyed with 9% of nickel and which have undergone double annealing followed by tempering, or hardening followed by tempering, have a minimum resilience, as determined by a Charpy V test at 35 J/cm2, at -1 960C.
Thus, it is desirable to provide a method of producing rolled steel satisfying the criteria mentioned above, the method being workable directly after rolling and the steel preferably containing a minimum of expensive alloying elements thereby reducing the cost of the rolled steel produced.
According to the present invention, there is provided a method of producing rolled steel, which comprises subjecting steel containing carbon, manganese, silicon, aluminium and, optionally, niobium to rolling in at least three passes to produce a rolled product, the total reduction during the three passes or the last three passes as he case may be being at least 20%, and the temperature before, during and after rolling being regulated such that the elasticity limit and resilience at -120"C of the rolled product (as calculated from the expressions:: LE=1035+5i0C+192Mn+2270Nb-0.21T1-0.40T2-0.48T3-3.51 D KCV=2202-2066C+23.20Mn-2064Nb-0.77T1-1 .24T2-0.23T3-1 .98D wherein C is the carbon content of the steel, Mn is the manganese content of the steel, Nb is the niobium content, if any, of the steel, T7 is the temperature of steel before rolling, T2 is the temperature of the steel during rolling, T3 is the temperature of the steel after rolling, D is the diameter or largest sectional width of the steel after rolling, LE is the elasticity limit, and KCV is the resilience at --120"C) attain the desired high values.
As an example of the application of the above expressions, consider the case wherein the carbon content C is 0.08%, the manganese content Mn is 1.60%, the niobium content Nb is 0%, the temperature T1 is 1000 0C , the temperature T2 is 8000C, the temperature T3 is 6500C and the diameter
D is 1 6 mm. Substituting these values in the above expressions, one obtains a value of 469 MPa for the elasticity limit LE and a value of 130 Joules for the resilience KCV at --1200C.
The concentrations of the various elements present or added, as well as the temperatures of the different treatment phases, varies only within certain limits.
Thus, the chemical composition of the steel used is chosen according to the knowledge acquire during the course of numerous test, which have revealed that the carbon content of the steel is preferably less than 0.20%. The lower the carbon content, the lower will be the transition temperature.
For example, the carbon content is preferably not more than 0.08% for a transition temperature, in a
Charpy V test at 35 J/cm2, at --1400C.
A manganese content in the region of 1.7% gives the steel the desired resilience while improving its tenacity, whilst a silicon content in the region of 0.3% is appropriate for strengthening the resilience.
Moreover, it is important to kill the steel to fine grain with aluminium in order to improve the weldability and reduce considerably the tendencey to age. Refining the grain also increases the elasticity limit as well as the tenacity.
The niobium, and possibly the vanadium and/or the molybdenum, will ensure a high elasticity limit, more particularly for concrete-reinforcing bars of large diameter.
According to the invention, the steel is subjected to the particular thermomechanical cycle described during the course of which the temperature of the steel is controlled for all the operations before, during and after rolling. The total reduction rate during the rolling passes should be high, preferably in excess of 20%.
The object of the particular thermomechanical cycle which forms part of the method according tor the invention is to obtain a product with an extremely fine grain at the core thereof, given that resilience at very low temperatures must be attained at the core.
In orderto obtain this result, firstly, the temperature of the furnace is appropriately chosen, in accordance with parameters known in the art, such that enlargment of the grain of the semi-finished product is prevented. Secondly, the starting temperature for rolling is such that from the start of rolling the grain is refined considerably, and that too high a degree of recrystallisation is avoided.
Before the last three rolling passes, the steel may be subjected to rapid cooling in a cooling ramp to a temperature close to the transformation point Ar3. Preferably, after being rolled, the product is subjected to a cooling treatment consisting of rapid cooling of the product to a temperature at which the temperature of the core therefore is low enough to prevent recrystallisation.
The idea forming the basis of the present invention consists therefore in combining the beneficial effects which are obtainable by appropriate choice of the chemical elements incorporated in determined contents in the steel with the effects of a controlled interaction between the changes of the temperature of the product during the course of manufacture and the rates of reduction applied during rolling. The result obtained manifests itself in particular by an extremely fine grain size of the finishing product.
In order to obtain with greater ease products having transition temperatures lower than at least --1400C, it is possible according to the invention to use a steel which has a nickel content in the region of 5%, but less than 10%. A steel of this type, rolled in accordance with the method according to the invention, has resilience, in a Charpy V test at 35 J/cm2, at-1960C.
The advantages of the method according to the invention as illustrated by the following six
Experiments.
Experiment 1
A naturally hard steel (carbon content approximately 0.35%) for concrete-reinforcing bars was rolled to produce a product having satisfactory tensile characteristics, in particular, an elasticity limit exceeding 400 MPa. However, the transition temperature of the product, in a Charpy V test at 35 J/cm2, was only 200C. This product therefore does not have any tenacity at low temperatures. Its weldability was mediocre.
Experiment 2
Steel with a carbon content of 0.18% was rolled according to the invention (i.e. was subjected to temperature regulation before, during and after rolling) to produce a product which, like the product of
Experiment 1, has satisfactory traction characteristics. The product of this Experiment was however better than that of Experiment 1 from the point of view of lengthening and more particularly in respect of the transition temperature, which was -600C. The product was weldable.
Experiment 3
Steel having a chemical composition in accordance with in the present invention, was rolled, but not in accordance with the invention, to produce a product whose mechanical characteristics, namely elasticity limit and resilience were insufficient. The stretching was increased, as compared to the product of Experiment 2. However, the transition temperature, even though the steel had not been rolled in accordance with the invention, was at approximately the same level as that of the product of
Experiment 2, which had been produced by rolling in accordance with the invention (i.e. had been subjected to temperature regulation before, during and after rolling).
Experiment 4
It was found that the combination of the use of steel having a chemical composition and in accordance with the invention and the use of temperature regulation before, during and after rolling in accordance with to the invention enabled one to obtain the desired improvement, namely satisfactory mechanical characteristics and increased stretching and a transition temperature reduced to a very low temperature i.e. a temperature of at least --1400C.
Experiment 5
Steel containing 6% nickel was subjected to normal hot rolling. The rolled product had a normal transition temperature, in a Charpy V test at 35 J/cm2 at --500C.
Experiment 6
In the case of the steel used in Experiment 5, resilience at -1 960C is normally aftainableonly by the use of an expensive thermal treatment (i.e. double annealing + tempering or hardening + tempering). However, when this steel was rolled whilst subjected to the temperature regulation before, during and after rolling, in accordance with the invention, the resulting rolled product had a transition temperature of -1 960C.
The six Experiments above are summarized in Table 1 below.
For the method according to the invention, the importance of the chemical composition of the steel, of the control of the temperatures during rolling and of rapid cooling after rolling is shown by the following six Experiments.
Experiment 7
A naturally hard steel (carbon content approximately 0.35%) for concrete-reinforcing bars was rolled in accordance with the method of the invention and hardened at the core. The rolled product had 'a high elasticity limit, but its ductility properties were very poor. In a Charpy V test, even at ambient temperature, the load did not exceed 35 J/cm2.
Experiment 8
Steel having a chemical composition in accordance with the invention was rolled without applying the temperature regulation according to the invention. The rolled product had inadequate mechanical
characteristics, namely elasticity limit and resilience. The transition temperature, in a Charpy V resilience test, was 600 C.
Experiment 9
The same steel as used in Experiment 8 was rolled without thermomechanical treatment but with cooling after rolling. The rolled product had an elasticity limit and a resilience clearly greater than the rolled product of Experiment 8. The transition temperature (-750C) was also improved as compared to that of the rolled product of Experiment 8.
Experiment 10
The procedure of Experiment 9 was repeated with thermomechanical rolling, but solely for the final pass. The elasticity limit and the resilience of the rolled product were greater than those of the rolled product of Experiment 8. The same applies to the transition temperature (which in this case was -1000C).
Experiment 11
The procedure of Experiment 9 was repeated with thermomechanical treatment in all of the rolling operations but without cooling after rolling. The elasticity limit and the resilience of the rolled product were lower than those of the rolled products of Experiments 9 and 10. The transition temperature, however, was improved (i.e. it was --1 15"C).
Experiment 12
The best results in respect of the mechanical properties of rolled steel having a chemical composition as required by the present invention were obtained by the treatment according to the
invention before, during and after rolling. In other words, the rolled product had satisfactory mechanical characteristics and increased stretching and a very low transition temperature in a Charpy V resilience test.
The results of Experiments 7 to 12 are summarized in Table 2 below.
Although the above description relates mainly to the production of round bars for reinforcing concrete, the method according to the invention can be applied equally well to other commercial steels
(such as smooth round members, flat members, square members, angle members, and section
members) and to sheets, when it is desirable to produce a product to combining the properties of weldability, of a high elasticity limit and of resilience at very low temperature.
TABLE 1
Experiment No. 1 2 3 4 5 6 Type of steel C = 0.35% C = 0.18% C = 0.08% C = 0.08% Ni = 9% Ni = 9% semi-killed semi-killed killed killed killed killed Treatment according to the invention, before, during and after rolling NO YES NO YES NO YES Elasticity limit (MPa) 440 470 320 490 890 710 Resilience (MPa) 650 570 500 570 1010 940 Stretching (10d) (%) 13 25 25 30 9 13 Transition temperature C (Charpy V resilience test at 35 J/cm2) 20 -60 -60 -140 -50 -196 TABLE 2
Experiment No. 7 8 9 10 11 12 Type of steel C = 0.35% C = 0.05% C = 0.05% C = 0.05% C = 0.05% C = 0.05% semi-killed killed A1 killed A1 killed A1 killed A1 killed A1 Furnace temperature controlled 1200 C 1200 C 1200 C controlled controlled Temperature of start of rolling controlled not controlled not controlled not controlled controlled controlled Rapid intermediary cooling yes no no yes yes yes Temperature at end of cooling controlled not controlled not controlled controlled controlled controlled Rapid cooling after rolling yes no yes yes no yes Temperature after rapid cooling after rolling controlled - controlled controlled - controlled Elasticity limit (MPa) 980 320 430 470 380 490 Resilience (MPa) 980 480 530 550 465 580 Stretching (5d) (%) 5 34 32 31 36 32 Transition temperature ( C) (Charpy V resilience test at 35 J/cm2 > 2 -60 -75 -100 -115 -140
Claims (12)
1. A method of producing rolled steel, which comprises subjecting steel containing carbon, manganese, silicon, aluminium and niobium to rolling in at least three passes to produce a rolled product, the total reduction during the three passes or the last three passes as the case may be being at least 20%, and temperature before, during and after rolling being regulated such that the elasticity limit and resilience at -1 200C of the rolled product (as calculated from the expressions:: LE=1035+510C+ 92Mn+2270Nb-0.21 T1-0.40T2-0.48T3-3.5 1 D
KCV=2202-2066C+23.20Mn-2064Nb-0.77T1-1 . 24T2-0.23T2-1 .98D wherein C is the carbon content of th steel, Mn is the manganese content of the steel, Nb is the niobium content, if any, of the steel, T1 is the temperature of the steel before rolling, T2 is the temperature of the steel during rolling, T3 is the temperature of the steel after rolling, D is the diameter of the steel after rolling or the largest sectional width of the rolled steel when the rolled steel has a non-circular section,
LE is the elasticity limit, and KCV is the resilience at -1 200 C) attain a value as high as possible.
2. A method according to claim 1, wherein the steel has a carbon content of less than 0.20%.
3. A method according to claim 1 or 2, wherein the steel is one which has been subjected to killing (i.e. deoxidation) by the addition of aluminium in an amount of at least 0.03%.
4. A method according to any of claims 1 to 3, wherein the steel has a nickel content of not more than 10%.
5. A method according to any of claims 1 to 4, wherein the steel contains vanadium and/or molybdenum.
6. A method according to any of claims 1 to 5, wherein the temperature of the steel is regulated before rolling by virtue of the fact that the steel emerges from a furnace whose temperature is regulated so as to be less than 1 2000C.
7. A method according to any of claims 1 to 6, wherein, before the steel is rolled in the three passes or in the last three passes as the case may be, it is rapidly cooled to a temperature corresponding to the transformation point Ar3.
8. A method according to any of claims 1 to 7, wherein, at the end of rolling, the rolled product is rapidly cooled to a temperature at which the temperature of the core thereof is low enough to prevent recrystallisation.
9. A method according to claim 1, substantially as described herein.
10. Rolled steel produced by a method according to any of claims 1 to 9.
11. Rolled steel as claimed in claim 10, in the form of bars for reinforcing concrete.
12. Rolled steel as claimed in claim 11, in the form of round bars for reinforcing concrete.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| LU82408A LU82408A1 (en) | 1980-04-28 | 1980-04-28 | PROCESS FOR MANUFACTURING STEEL LAMINES HAVING GOOD WELDABILITY, HIGH ELASTICITY LIMIT AND RESILIENCE AT VERY LOW TEMPERATURES |
| LU82987A LU82987A1 (en) | 1980-12-08 | 1980-12-08 | PROCESS FOR THE MANUFACTURE OF STEEL LAMINES HAVING GOOD WELDING, A HIGH ELASTICITY LIMIT AND RESILIENCE AT VERY LOW TEMPERATURES |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2075390A true GB2075390A (en) | 1981-11-18 |
| GB2075390B GB2075390B (en) | 1983-06-29 |
Family
ID=26640265
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8112955A Expired GB2075390B (en) | 1980-04-28 | 1981-04-27 | Method of producing rolled steel |
Country Status (12)
| Country | Link |
|---|---|
| AT (1) | AT382642B (en) |
| AU (1) | AU542064B2 (en) |
| BR (1) | BR8100215A (en) |
| CA (1) | CA1159286A (en) |
| CH (1) | CH640569A5 (en) |
| DE (1) | DE3107669A1 (en) |
| ES (1) | ES501716A0 (en) |
| FR (1) | FR2481321B1 (en) |
| GB (1) | GB2075390B (en) |
| IT (1) | IT1209295B (en) |
| NL (1) | NL8100232A (en) |
| SE (1) | SE8100496L (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5325697A (en) * | 1991-05-06 | 1994-07-05 | Morgan Construction Company | Method and apparatus for continuously hot rolling ferrous long products |
-
1980
- 1980-12-19 CA CA000367171A patent/CA1159286A/en not_active Expired
- 1980-12-23 IT IT8026926A patent/IT1209295B/en active
-
1981
- 1981-01-14 CH CH22681A patent/CH640569A5/en not_active IP Right Cessation
- 1981-01-15 BR BR8100215A patent/BR8100215A/en unknown
- 1981-01-19 NL NL8100232A patent/NL8100232A/en not_active Application Discontinuation
- 1981-01-21 FR FR8027493A patent/FR2481321B1/en not_active Expired
- 1981-01-27 SE SE8100496A patent/SE8100496L/en unknown
- 1981-02-28 DE DE19813107669 patent/DE3107669A1/en not_active Withdrawn
- 1981-03-04 AT AT0099981A patent/AT382642B/en not_active IP Right Cessation
- 1981-04-06 AU AU69112/81A patent/AU542064B2/en not_active Ceased
- 1981-04-27 GB GB8112955A patent/GB2075390B/en not_active Expired
- 1981-04-28 ES ES501716A patent/ES501716A0/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5325697A (en) * | 1991-05-06 | 1994-07-05 | Morgan Construction Company | Method and apparatus for continuously hot rolling ferrous long products |
Also Published As
| Publication number | Publication date |
|---|---|
| ATA99981A (en) | 1986-08-15 |
| IT1209295B (en) | 1989-07-16 |
| FR2481321A1 (en) | 1981-10-30 |
| SE8100496L (en) | 1981-10-29 |
| AU6911281A (en) | 1981-11-05 |
| BR8100215A (en) | 1982-01-12 |
| NL8100232A (en) | 1981-11-16 |
| CA1159286A (en) | 1983-12-27 |
| ES8207586A1 (en) | 1982-09-16 |
| GB2075390B (en) | 1983-06-29 |
| FR2481321B1 (en) | 1986-11-21 |
| IT8026926A0 (en) | 1980-12-23 |
| CH640569A5 (en) | 1984-01-13 |
| AT382642B (en) | 1987-03-25 |
| DE3107669A1 (en) | 1982-02-25 |
| ES501716A0 (en) | 1982-09-16 |
| AU542064B2 (en) | 1985-02-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |