US3076361A - Rolling steel in ferritic state - Google Patents
Rolling steel in ferritic state Download PDFInfo
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- US3076361A US3076361A US28808A US2880860A US3076361A US 3076361 A US3076361 A US 3076361A US 28808 A US28808 A US 28808A US 2880860 A US2880860 A US 2880860A US 3076361 A US3076361 A US 3076361A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
- B21B1/24—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process
- B21B1/26—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process by hot-rolling, e.g. Steckel hot mill
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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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B2201/00—Special rolling modes
- B21B2201/04—Ferritic rolling
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S72/00—Metal deforming
- Y10S72/70—Deforming specified alloys or uncommon metal or bimetallic work
Definitions
- ROLLING STEEL IN FERRITIC STATE 3 Sheets-Sheet 3 HIGH TE MPE RA TURE TENS/LE TEST 66 may SPEED 0/0405 I l x I I 2a000 i-DEFORMHT/0/V INVENTORS Samuel Epsl'e/n John M Frame aha/ eorge F. Mel/0 ATTORNEY United States Patent Ofifice 3,076,361 Patented Feb. 5, 1963 3,076,361 ROLLENG STEEL IN FERRITIC STATE Samuel Epstein, John W. Frame, and George F. Melloy, Bethlehem, Pat, assignors to Bethlehem Steel Company, a corporation of Pennsylvania Filed May 12, 1960, Ser. No. 28,808 19 Claims. (Cl.
- nitriding steel for example, decarburization causes the nitrided layer to be weak and brittle. Decarburization that at which any substantial work hardening takes place during rolling.
- Bars rolled by conventional hot rolling methods must frequently be slow cooled or subjected to various thermal treatments to avoid defects such as cooling cracks, thermal ruptures, etc., associated with rapid cooling from the rolling temperature. Such treatments are unnecessary with bars produced by our method as above described.
- bars produced from billets in accordance with our process have excellent surface finish.
- the bars are substantially free from decarburization and scale and therefore do not require corrective surface treatment.
- Bars rolled by our method retain the metallurgical and mechanical properties of the billets from which they are formed.
- FIGS. 1, 2 and 3 are graphs of high temperature tensile tests, showing tensile strength, elongation, and reduction of area at various temperatures of a 10-120 grade tool steel, of a nitriding steel, and of a high speed steel, re-
- Decarburization is highly undesirable and it therefore is necessary to remove the decarburized'surface by grinding, or to restore carbon by a recarburization treatmentboth processes being expensive and undesirable.
- the billet is first given the heat treatment necessary to produce the properties desired in the finished bar.
- Such heat treatments may consist of annealing, normalizing, spherodize annealing, quenching and tempering, or other treatment processing designed to produce a product having specified physical properties.
- the billet is then treated by conventional methods to remove scale and decarburization.
- Such methods include chipping, scarfing, turning, grinding and/ or pickling.
- the-nitriding steel illustrated containing carbon .42%, mangauese .63%, phosphorus .026%, sul- 'phur 026%, silicon 32%, chromium'1.57,%,-molybdenum 34%, and aluminum 1.10% has properties mak-- ing it suitable for hot-rolling within an approximate temperature range of about 1470 F. to 1350 'F.; that the high speed steel illustrated, containing carbon .83%, chromium 3.97%, molybdenum 4.73%,tungsten '6.37%,- and vanadium 1.88% has properties making it suitable-for hot rolling within an approximate temperature range of about 1520 F. tol350 F.
- the rolling temperature should beas close to the A temperature as possible, and above the temperature at which the tensile strength begins to rise" steeply and the ductility begins to fall rapidly with small" p Accordingly it is essential whenrolling in accordance with our invention not to,
- a nitriding steel having a lower critical temperature, on heating, of 1440 F. was rolled between 1.420 F. starting temperature and 1400" F. finishing temperature without substantial work hardening; and a C1018 carbon steel having a lower critical temperature of- 1370 F. was rolled in a temperature range of 1370 F. to 1350* F. without substantial work hardening.
- breaks and tears are more apt to form in higher carbon and highly alloyed steels, and this may also occasionally be true in our low temperature warm rolling process. But just as breaks and tears can be avoided during ordinary hot rolling of these more sensitive higher carbon highly alloyed steels by paying special attention to proper grinding and annealing of the billets before rolling and by normal adjustments of the roll passes, so also, breaks and tears in the more sensitive steels can be avoided in the same way in our warm rolling process.
- the surface of the warm rolled steel is especially good.
- the surface is of good enough quality to permit the use of such warm rolled product in automatic cutting machines without cleaning the warm rolled steel, cold drawing it, machining it, or the like, preparatory to feeding it into the automatic cutting machine.
- T 1. The method of producing rolled shapes of non-austenitic steel comprising normalizing a billet, spheriodizing said billet, removing scale and decarburization from said billet, heating the said billet to a temperature within a range not higher than the lower critical temperature, on heating, of said steel and not lower than 100 F. below said critical temperature, and rolling said steel while within said temperature range.
- the 'metho'd fproducing rolled shapes of nonaustenitic steel comprising normalizing a billet, spheroidizing said billet", -removing scale and decarburization from said billet, heating the said billet to a temperature within a range not higher than the lower critical temperature, on heating, of said'steeland'not lower than 200 F. below said critical temperature, and rolling said steel while within said temperature range.
- the method of producing rolled shapes of nonaustenitic steel comprising spheroidizing a billet, removing scale and decarburization from said billet, heating the said billet to a temperature within a range not higher than the lower critical temperature, on heating, of said steel and not lower than 100 F. below said critical temperature, and rolling said steel while within said temperature range.
- the method of producing a rolled shape of nonaustenitic steel comprising heat treating a billet to produce therein the metallurgical and mechanical properties desired in the rolled shape, removing scale and decarburizetion from said billet, heating the said billet to a temperature within a range not higher than the lower critical temperature, on heating, of said steel and not lower than 100 F. below said critical temperature, and rolling said steel while within said temperature range.
- a process for the rolling of a steel billet containing C .38-45%, Mn .40-.7-0%, Si ill-.40%, Cr 1.401.80 Al .85-1.20%, Mo .30.45%, balance essentially iron comprising heat treating a billet of said steel to below a desired maximum hardness, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the lower mean critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range and while maintaining said hardness below said desired maximum hardness.
- a process for the rolling of a steel billet containing C .95l.l0%, Mn 25-45%, Si .2-035%, Cr l.20l.50%, balance essentially iron comprising heat treating a billet of said steel to below a desired maximum hardness, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet is still ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range, and while maintaining said hardness below said desired maximum hardness.
- a process for the rolling of a steel billet containing C 19-86%, 'Mn 35% max., Si .40% max., Cr 3.90- 4.40%, Mo 4.755.25%, V 1.752.05%, W 604.75%, balance essentially iron comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billetwhile within said temperature range, and while maintaining said properties.
- a process for the rolling of a steel billet containing C 1.15 1.50%, Mn .20-.45%, Si .10-.20%, balance essentially iron comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel biilet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain wholly ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the critical temperature, on heating, of the said steel billet, and rolling said steel billet While within said temperature range and while maintaining said properties.
- Method of producing rolled shapes of non-austenitic steel having close dimensional tolerances, free from decarburization and scale, and of specified maximum hardness comprising heat treating a billet of said steel to a hardness not greater than said specified maximum hardness, removing any decarburized and scaled areas from the surface of the billet, heating the billet to a temperature within a range not higher than the lower critical temperature, on heating, of said steel and not lower than approximately 200 F. below said critical temperature, and rolling the billet to finished form while maintaining the temperature of the steel within said range.
- a process for the hot-rolling of a non-austenitic steel billet while in the ferritic state comprising removing decarburization and scale from said steel billet, heating said steel billet to the upper range of temperatures at which the steel is still ferritic, said range having as a lower limit thereof, a temperature of approximately 100 F. below the critical temperature, on heating, of
- a process for the hot rolling of a non-austenitic steel billet while in the ferritic state comprising removing decarburization and scale from said steel billet, heating said steel billet to the upper range of temperatures at which the steel is still ferritic, said range having as a lower limit thereof a temperature of approximately 200 F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range.
- a process for the rolling of a steel billet containing C .38-.45%, Mn .40-.70%, Si .20.40%, Cr 1.40- 1.80%, Al .851.20%, Mo .30.45%, balance essentially iron comprising removing decarburization and scale from said steel billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range.
- a process for the rolling of a steel billet containing C .95-1.10%, Mn .25-.45%, Si .20-.35%, Cr 1.20- 1.50%, balance essentially iron, comprising removing decarburization and scale from said billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet is still ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the lower critical temperature, onheating, of said steel billet, and rolling said steel billet while within said temperature range.
- a process for the rolling of a steel billet containing C .79-.86%, Mn 35% max., Si .40% max., Cr 3.90-4.40%, Mo 4.75-5.25%, V 1.75-2.05%, W 6.0- 6.75%, balance essentially iron, comprising removing decarburization and scale from said billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 100 F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range.
- a process for the rolling of a steel billet containing C .73-.83%, Mn .40% max., Si .40% max., Cr 3.60- 4.10%, Mo 8.009.00%, V .90-1.20%, W 1.40-1.80%, balance essentially iron comprising removing decarburi- Zation and scale fromsaid billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereofi, a temperature of approximately F. below the critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range.
- a process for the rolling of a steel billet containing C 1.15-l.50%, Mn .20.45%, Si .10.20%, balance essentially iron comprising removing decarburization and scale from said billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain wholly ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the critical temperature, on heating, of the said steel billet, and rolling said steel billet while within said temperature range.
- the method of producing rolled shapes of nonaustenitic steel comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 100 F. below the critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range, and while maintaining said properties.
- the method of producing rolled shapes of nonaustenitic steel comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain wholly ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the critical temperature, on'heating, of the said steel billet, and rolling said steel billet while within said temperature range and while maintaining said properties.
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Description
Feb.
Filed May 12, 1960 TENS/LE STRENGTH (P67) S. EPSTEIN ETAL ROLLING STEEL IN FERRITIC STATE I Hon/'64 mm,
5 Sheets-Sheet l i i i .049 .0/0 ./4
EL o/ven r/o/v mvo R5006 7/0/1/ (Z) 0 A200 /400 I500 Hoe-Fo/wnr/o/v TEMPE/MTURE KAI/v65 TE 5 7711/6 TEMPERA TUBE "F I INVENTORS Samuel 'psfem c/qbn W. Frame and George E Mel/0y BY ATTORNEY Feb. 5, 1963 Filed May 12, 1960 TENS/LE STRE/VG 71/ (P51) 5. EPSTEIN ETAL 3,076,361
ROLLING STEEL IN FERRITIC STATE 3 Sheets-Sheet 3 HIGH TE MPE RA TURE TENS/LE TEST 66 may SPEED 0/0405 I l x I I 2a000 i-DEFORMHT/0/V INVENTORS Samuel Epsl'e/n John M Frame aha/ eorge F. Mel/0 ATTORNEY United States Patent Ofifice 3,076,361 Patented Feb. 5, 1963 3,076,361 ROLLENG STEEL IN FERRITIC STATE Samuel Epstein, John W. Frame, and George F. Melloy, Bethlehem, Pat, assignors to Bethlehem Steel Company, a corporation of Pennsylvania Filed May 12, 1960, Ser. No. 28,808 19 Claims. (Cl. 80-60) subject to appreciable decarburization and scaling which are very serious surface defects. These greatly detract from the quality of the finished product, especially where high surface hardness is necessary as' in tool steel. nitriding steel, for example, decarburization causes the nitrided layer to be weak and brittle. Decarburization that at which any substantial work hardening takes place during rolling.
Bars rolled by conventional hot rolling methods must frequently be slow cooled or subjected to various thermal treatments to avoid defects such as cooling cracks, thermal ruptures, etc., associated with rapid cooling from the rolling temperature. Such treatments are unnecessary with bars produced by our method as above described.
We find that bars produced from billets in accordance with our process have excellent surface finish. The bars are substantially free from decarburization and scale and therefore do not require corrective surface treatment. Bars rolled by our method retain the metallurgical and mechanical properties of the billets from which they are formed.
FIGS. 1, 2 and 3 are graphs of high temperature tensile tests, showing tensile strength, elongation, and reduction of area at various temperatures of a 10-120 grade tool steel, of a nitriding steel, and of a high speed steel, re-
' spectively. In these graphs it is evident that the tensile and scaling may add materially to the cost of grinding" the steel and otherwise preparing the surface of the product for its use in service.
Decarburization is highly undesirable and it therefore is necessary to remove the decarburized'surface by grinding, or to restore carbon by a recarburization treatmentboth processes being expensive and undesirable.
Furthermore, after normal high temperature rolling such steels usually must be cooled slowly from the rolling temperature to avoid excessive hardening, high residual stresses, cooling cracks, etc., and thereafter must normally be annealed or otherwise .heat treated in order to attain the desired metallurgical and mechani al P P- erties. Such heat treatment also causes decarburization and scaling.
Furthermore, with normal high temperature rolling is difiicult to attain an excellent surface finish.
It is therefore a broad object of this invention to provide a process for rolling steels which avoids the dangers of decarburization and scaling, etc. as mentioned above, and produces a rolled product of excellent surface finish and desired metallurgical and mechanical properties.
In the practice of our process we subject a billet of steel produced by conventional means to the following treatment:
(1) The billet is first given the heat treatment necessary to produce the properties desired in the finished bar.
In normal prior hot rolling practice this heat treatment would be given to the bars after rolling, because the eifects of any treatment given to the billet would be lost in the hot rolling. Such heat treatments may consist of annealing, normalizing, spherodize annealing, quenching and tempering, or other treatment processing designed to produce a product having specified physical properties.
(2) The billet is then treated by conventional methods to remove scale and decarburization. Such methods include chipping, scarfing, turning, grinding and/ or pickling.
(3) The billet is then heated to a temperature not higher than the lower critical temperature, on heating, of
the'steel (the A temperature) and not lower than 200 F. below the A temperature, and rolled to finished size while maintaining the temperature of the steel within said 'at' which'it 'is 'still' ferritic. 40"
In fact, the tensile strength and the plasticity of the steel at the upper temperatures at which the steel is still ferritic approximate that of steel heated to the normal the upper critical temperature of the steelr hot-rolling temperatures several hundred degrees above The graphs of FIGS. 1, 2 and 3 also indicate that upon heating to a temperature somewhat above the lower critical temperature on heating (the temperature A in the graphs) the tensile strength rises' and the ductility falls.
' This is because the austenitic condition of the steel in these temperature ranges has somewhat higher strength and lower ductility than the steel hasin the upper temperatures heatthe steel above the A critical temperature.
range. We prefer to roll at a temperature as close to the A temperature as possible, preferably not more than 50 to 100 F. below the A temperature. The temperature range will vary for different steels and should be above The temperature range below the A temperature, within which we roll will vary with different steels. The 2 data in the graphs ofFIGS. 1, 2 and 3 indicate that the tool steel illustrated, containing carbon 1.18%, manganese .41%, phosphorus 019%, sulphur 018%, silicon .14%, has properties making it suitable for hot-rolling within an approximate temperature range of about 1380 F. to 1270 F.; that the-nitriding steel illustrated, containing carbon .42%, mangauese .63%, phosphorus .026%, sul- 'phur 026%, silicon 32%, chromium'1.57,%,-molybdenum 34%, and aluminum 1.10% has properties mak-- ing it suitable for hot-rolling within an approximate temperature range of about 1470 F. to 1350 'F.; that the high speed steel illustrated, containing carbon .83%, chromium 3.97%, molybdenum 4.73%,tungsten '6.37%,- and vanadium 1.88% has properties making it suitable-for hot rolling within an approximate temperature range of about 1520 F. tol350 F. These temperature ranges l have been indicated by the vertical dot-dash broken lines in the graphs. In some cases it may be necessaryto restrict the range of rolling temperatures still further in order to avoid exceeding the annealed hardness. For instance, if his desired to retain the original annealed hardness of high speed steels such as shown in FIG; 3 a rolling range going no lower than F. below the A temperature is necessary.
Generally speaking, the rolling temperature should beas close to the A temperature as possible, and above the temperature at which the tensile strength begins to rise" steeply and the ductility begins to fall rapidly with small" p Accordingly it is essential whenrolling in accordance with our invention not to,
decreases in temperature, as shown in the drawings. Rolling at temperatures below this lower limit may result in breaks, corner and surface tears, and excessive hardening. Although the temperature ranges appear to be narrow, in practice the heat gained in deforming the steel in the various roll passes offsets to a large extent the normal heat losses, making it quite feasible to keep the steel in the desired temperature range. No reheating is necessary. We have'found that the lower limit for successful rolling lies approximately 200 F. below the lower critical temperature; on heating, of the steel being rolled. However, it is preferable to maintain the steel at a temperature not more than 50 to 100 below the A temperature. It should be pointed out that each type of steel and even specific analyses of steel within such types, have ideal lower limits of temperature above which rolling will be most successful.
Among the various steels which have been investigated and which exhibit a similar temperature range for hot rolling in the ferritic state are those steels which fall within the following ranges of composition:
0, Mn, P, 8, r percent percent percent percent percent It was desired to produce bars having a maximum Brinell hardness of 187. These billets were normalized Carbon Tool Steel 0, percent Mn, percent Si, percent Cr, percent; Al,percent Mo, percent V, percent W, percent l.lll.fi0 I l.,45 .10 20 A BallBearlng Steel Alb/1.10 I .25/.45 .20l.35 1.20/l.50 I Nltrlding Steel .08I.45 .40[.70 .20I.40 1.40/L80 .8 5/L2 0 .30I.45
High Speed Steels 1131158 3131'. :38 33;: 213.5% 7 2585313 "Tilt? 11121137 Automotive Axle Steel 7 32/19 170 .00 l5/.'30 I i 7 Free Machlning Steel .12: max. 4011.00 .o1-.12 .1e-.2a
It is here pointed out, however, that these steels are only a few examples of non-austenitic steels which can be advantageously rolled by the process of our invention. Theinvention is applicable to all steels which are normally non-austenitic.
For example, a nitriding steel having a lower critical temperature, on heating, of 1440 F. was rolled between 1.420 F. starting temperature and 1400" F. finishing temperature without substantial work hardening; and a C1018 carbon steel having a lower critical temperature of- 1370 F. was rolled in a temperature range of 1370 F. to 1350* F. without substantial work hardening.
To'give a typical example of our procedure the follow ing nitriding steel was rolled according to the invention.
0, Mn, P, 8, Si, Cr, Mo, Al, percent percent percent percent percent percent percent percent .38 .00 i .015 l .001 .28 l 1.50 .37 1.17
at 1600 F. and spheroidized at a temperature of 1420" F. to a hardness of Brinell, and the surface defects removed by grinding. The billets were then heated to 1300 F. and rolled into bars at this temperature, which is approximately 55 F. below the lower critical temperature, on heating, for this steel. The final hardness of the rQlled bars was 163-170 Brinell.
We have found that sections difficult to roll, such as sharp cornered squares, can be rolled by our process.
In ordinary hot rolling, breaks and tears are more apt to form in higher carbon and highly alloyed steels, and this may also occasionally be true in our low temperature warm rolling process. But just as breaks and tears can be avoided during ordinary hot rolling of these more sensitive higher carbon highly alloyed steels by paying special attention to proper grinding and annealing of the billets before rolling and by normal adjustments of the roll passes, so also, breaks and tears in the more sensitive steels can be avoided in the same way in our warm rolling process.
When conditioning billets prior to warm rolling by scarfing and pickling, light scabs may show on the bars after rolling, but when the conditioning is done by chipping instead of scarfing, and then pickling, no such scabs appear and a very good surface is obtained-much better than the surface obtained by ordinary hot rolling at temperatures high above the upper critical.
As has been stated, the surface of the warm rolled steel is especially good. The surface is of good enough quality to permit the use of such warm rolled product in automatic cutting machines without cleaning the warm rolled steel, cold drawing it, machining it, or the like, preparatory to feeding it into the automatic cutting machine.
It will be clearly apparent from the foregoing description that our novel low temperature process as defined in the claims will have many advantages over the prior art rolling processes which take place at much higher temperatures in the austenitic state, e.g., we have discovered the following advantages:
, (1) Substantially no decarburization occurs on the rolled bars. Accordingly, subsequent treatment of the bars to remove decarburization or to restore carbon is unnecessary.
- (2) Formation of scale is substantially avoided thereby eliminating the need for removing the scale.
(3) Superior surface finish.
(4) Better sizing.
(5) Slow cooling after rolling into bars is not required.
(6) The rolled bars retain the metallurgical and mechanical properties of the billets from which they are formed;
While we have thus described our invention in considerable detail we do not wish to be limited narrowly to the exact and specific particulars disclosed, but we may also use such substitutes, modifications, or equivalents as are included within the scope and spirit of the invention or pointed out in the appended claims.
We claim: 1 r
T 1..The method of producing rolled shapes of non-austenitic steel comprising normalizing a billet, spheriodizing said billet, removing scale and decarburization from said billet, heating the said billet to a temperature within a range not higher than the lower critical temperature, on heating, of said steel and not lower than 100 F. below said critical temperature, and rolling said steel while within said temperature range.
2. The 'metho'd fproducing rolled shapes of nonaustenitic steel comprising normalizing a billet, spheroidizing said billet", -removing scale and decarburization from said billet, heating the said billet to a temperature within a range not higher than the lower critical temperature, on heating, of said'steeland'not lower than 200 F. below said critical temperature, and rolling said steel while within said temperature range.
3, The method of producing rolled shapes of nonaustenitic steel comprising spheroidizing a billet, removing scale and decarburization from said billet, heating the said billet to a temperature within a range not higher than the lower critical temperature, on heating, of said steel and not lower than 100 F. below said critical temperature, and rolling said steel while within said temperature range.
4. The method of producing a rolled shape of nonaustenitic steel comprising heat treating a billet to produce therein the metallurgical and mechanical properties desired in the rolled shape, removing scale and decarburizetion from said billet, heating the said billet to a temperature within a range not higher than the lower critical temperature, on heating, of said steel and not lower than 100 F. below said critical temperature, and rolling said steel while within said temperature range.
5. A process for the rolling of a steel billet containing C .38-45%, Mn .40-.7-0%, Si ill-.40%, Cr 1.401.80 Al .85-1.20%, Mo .30.45%, balance essentially iron, comprising heat treating a billet of said steel to below a desired maximum hardness, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the lower mean critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range and while maintaining said hardness below said desired maximum hardness.
6. A process for the rolling of a steel billet containing C .95l.l0%, Mn 25-45%, Si .2-035%, Cr l.20l.50%, balance essentially iron, comprising heat treating a billet of said steel to below a desired maximum hardness, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet is still ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range, and while maintaining said hardness below said desired maximum hardness.
7. A process for the rolling of a steel billet containing C 19-86%, 'Mn 35% max., Si .40% max., Cr 3.90- 4.40%, Mo 4.755.25%, V 1.752.05%, W 604.75%, balance essentially iron, comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billetwhile within said temperature range, and while maintaining said properties.
8. A process for the rolling of a steel billet containing C .73-.83%, Mn .40% max., Si .40% max., Cr 3.604.10%, Mo 8.00-9.00%, V .90-1.20%, W 1.40-
l.80%, balance essentially iron, comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 100 F. below the critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range, and while maintaining said properties.
9-. A process for the rolling of a steel billet containing C 1.15 1.50%, Mn .20-.45%, Si .10-.20%, balance essentially iron, comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel biilet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain wholly ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the critical temperature, on heating, of the said steel billet, and rolling said steel billet While within said temperature range and while maintaining said properties.
10. Method of producing rolled shapes of non-austenitic steel having close dimensional tolerances, free from decarburization and scale, and of specified maximum hardness, comprising heat treating a billet of said steel to a hardness not greater than said specified maximum hardness, removing any decarburized and scaled areas from the surface of the billet, heating the billet to a temperature within a range not higher than the lower critical temperature, on heating, of said steel and not lower than approximately 200 F. below said critical temperature, and rolling the billet to finished form while maintaining the temperature of the steel within said range.
11. A process for the hot-rolling of a non-austenitic steel billet while in the ferritic state, comprising removing decarburization and scale from said steel billet, heating said steel billet to the upper range of temperatures at which the steel is still ferritic, said range having as a lower limit thereof, a temperature of approximately 100 F. below the critical temperature, on heating, of
said steel billet, and rolling said steel billet within said range.
12. A process for the hot rolling of a non-austenitic steel billet while in the ferritic state, comprising removing decarburization and scale from said steel billet, heating said steel billet to the upper range of temperatures at which the steel is still ferritic, said range having as a lower limit thereof a temperature of approximately 200 F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range.
13. A process for the rolling of a steel billet containing C .38-.45%, Mn .40-.70%, Si .20.40%, Cr 1.40- 1.80%, Al .851.20%, Mo .30.45%, balance essentially iron, comprising removing decarburization and scale from said steel billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range.
14. A process for the rolling of a steel billet containing C .95-1.10%, Mn .25-.45%, Si .20-.35%, Cr 1.20- 1.50%, balance essentially iron, comprising removing decarburization and scale from said billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet is still ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the lower critical temperature, onheating, of said steel billet, and rolling said steel billet while within said temperature range.
15. A process for the rolling of a steel billet containing C .79-.86%, Mn 35% max., Si .40% max., Cr 3.90-4.40%, Mo 4.75-5.25%, V 1.75-2.05%, W 6.0- 6.75%, balance essentially iron, comprising removing decarburization and scale from said billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 100 F. below the lower critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range.
16. A process for the rolling of a steel billet containing C .73-.83%, Mn .40% max., Si .40% max., Cr 3.60- 4.10%, Mo 8.009.00%, V .90-1.20%, W 1.40-1.80%, balance essentially iron, comprising removing decarburi- Zation and scale fromsaid billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereofi, a temperature of approximately F. below the critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range.
17. A process for the rolling of a steel billet containing C 1.15-l.50%, Mn .20.45%, Si .10.20%, balance essentially iron, comprising removing decarburization and scale from said billet, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain wholly ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the critical temperature, on heating, of the said steel billet, and rolling said steel billet while within said temperature range.
18. The method of producing rolled shapes of nonaustenitic steel comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain ferritic and having as the lower limit thereof, a temperature of approximately 100 F. below the critical temperature, on heating, of said steel billet, and rolling said steel billet while within said temperature range, and while maintaining said properties.
19. The method of producing rolled shapes of nonaustenitic steel comprising heat treating a billet of said steel to produce therein the metallurgical and mechanical properties desired in the rolled shape, heating said steel billet to within a temperature range having as the upper limit thereof, the highest temperature at which said steel billet will remain wholly ferritic and having as the lower limit thereof, a temperature of approximately 200 F. below the critical temperature, on'heating, of the said steel billet, and rolling said steel billet while within said temperature range and while maintaining said properties.
References Cited in the file of this patent The Making, Shaping and Treating of Steel, Seventh Edition, copyright 1957 by US. Steel Corporation.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,076,361 February 5, 1963 Samuel Epstein et alt,
It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Columns 3 and .4, in the table, under the heading "High Speed Steels, and under the column heading "W, percent" for "L l/18.," read lo l/108 column 5, line 68, for ".38--45%" read n38u45% column 6, line 6 for "25-45%" read .,2545% same line for ,2035%" read o 20 435% same column, line 18 for "e7986%" read .79.,86% 7 same line, for "35% max," read 035% max,
Signed and sealed this 3rd day of September 1963,
(SEAL) Attest' ERNEST W. SWIDER Attesting Officer DAVID L. LADD Commissioner of Patents
Claims (1)
19. THE METHOD OF PRODUCING ROLLED SHAPES OF NONAUSTENITIC STEEL COMPRISING HEAT TREATING A BILLET OF SAID STEEL TO PRODUCE THEREIN THE METALLURGICAL AND MECHANICAL PROPERTIES DESIRED IN THE ROLLED SHAPE, HEATING SAID STEEL BILLET TO WITHIN A TEMPERTURE RANGE HAVING AS THE UPPER LIMIT THEREOF, THE HIGHEST TEMPERATURE AT WHICH SAID STEEL BILLET WILL REMAIN WHOLLY FERRITIC AND HAVING AS THELOWER LIMIT THEREOF, A TEMPERATURE OF APPROXIMATELY 200*F. BELOW THE CRITICAL TEMPERATURE, ON HEATING, OF THE SAID STEEL BILLET, AND ROLLING SAID STEEL BILLET WHILE WITHIN SAID TEMPERATURE RANGE AND WHILE MAINTAINING SAID PROPERTIES.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US28808A US3076361A (en) | 1960-05-12 | 1960-05-12 | Rolling steel in ferritic state |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US28808A US3076361A (en) | 1960-05-12 | 1960-05-12 | Rolling steel in ferritic state |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3076361A true US3076361A (en) | 1963-02-05 |
Family
ID=21845546
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US28808A Expired - Lifetime US3076361A (en) | 1960-05-12 | 1960-05-12 | Rolling steel in ferritic state |
Country Status (1)
| Country | Link |
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| US (1) | US3076361A (en) |
Cited By (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3316068A (en) * | 1965-10-21 | 1967-04-25 | Lindsay Wire Weaving Co | Wire belt for use in paper making machines |
| US3459599A (en) * | 1966-10-17 | 1969-08-05 | United States Steel Corp | Method of thermomechanically annealing steel |
| US3523833A (en) * | 1967-03-14 | 1970-08-11 | Boehler & Co Ag Geb | Method of improving the properties of alloy steel castings |
| US3892602A (en) * | 1972-04-10 | 1975-07-01 | Bethlehem Steel Corp | As-worked, heat treated cold-workable hypoeutectoid steel |
| USRE29240E (en) * | 1973-05-09 | 1977-05-31 | Bethlehem Steel Corporation | As-worked, heat treated cold-workable hypoeutectoid steel |
| US5094698A (en) * | 1990-10-24 | 1992-03-10 | Consolidated Metal Products, Inc. | Method of making high strength steel parts |
| US5236520A (en) * | 1990-10-24 | 1993-08-17 | Consolidated Metal Products, Inc. | High strength steel sway bars and method of making |
| US5330594A (en) * | 1990-10-24 | 1994-07-19 | Consolidated Metal Products, Inc. | Method of making cold formed high-strength steel parts |
| US5453139A (en) * | 1990-10-24 | 1995-09-26 | Consolidated Metal Products, Inc. | Method of making cold formed high-strength steel parts |
| US5454888A (en) * | 1990-10-24 | 1995-10-03 | Consolidated Metal Products, Inc. | Warm forming high-strength steel structural members |
| US5496425A (en) * | 1990-10-24 | 1996-03-05 | Consolidated Metal Products, Inc. | Cold formed high-strength steel structural members |
| US5538566A (en) * | 1990-10-24 | 1996-07-23 | Consolidated Metal Products, Inc. | Warm forming high strength steel parts |
| US5704998A (en) * | 1990-10-24 | 1998-01-06 | Consolidated Metal Products, Inc. | Hot rolling high-strength steel structural members |
| US6325874B1 (en) | 1999-12-03 | 2001-12-04 | Consolidated Metal Products, Inc. | Cold forming flat-rolled high-strength steel blanks into structural members |
| US20030111143A1 (en) * | 2001-10-23 | 2003-06-19 | Consolidated Metal Products, Inc. | Flattened U-bolt and method |
| US20080229893A1 (en) * | 2007-03-23 | 2008-09-25 | Dayton Progress Corporation | Tools with a thermo-mechanically modified working region and methods of forming such tools |
| US20090229417A1 (en) * | 2007-03-23 | 2009-09-17 | Dayton Progress Corporation | Methods of thermo-mechanically processing tool steel and tools made from thermo-mechanically processed tool steels |
| US20110253826A1 (en) * | 2008-11-07 | 2011-10-20 | Polimeri Europa S.P.A. | Granulator blades with a high wear resistance and sharpening method thereof |
| RU2499638C1 (en) * | 2012-08-21 | 2013-11-27 | Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Национальный исследовательский технологический университет "МИСиС" | Strip hot rolling |
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| US938893A (en) * | 1909-11-02 | Manganese Steel Rail Company | Process of rolling manganese steel. | |
| US1711000A (en) * | 1925-07-02 | 1929-04-30 | Gen Motors Res Corp | Method of making wrought-metal articles |
| US2400866A (en) * | 1941-11-08 | 1946-05-21 | United Drill And Tool Corp | Method of drawing metal stock |
| US2767835A (en) * | 1955-06-27 | 1956-10-23 | Lasalle Steel Co | Process of extruding steel |
| US2881107A (en) * | 1956-10-22 | 1959-04-07 | Lasalle Steel Co | Austempered, cold-finished steels |
| US2924544A (en) * | 1956-10-22 | 1960-02-09 | Lasalle Steel Co | Metallurgical process for cold-finishing steel |
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| US938893A (en) * | 1909-11-02 | Manganese Steel Rail Company | Process of rolling manganese steel. | |
| US1711000A (en) * | 1925-07-02 | 1929-04-30 | Gen Motors Res Corp | Method of making wrought-metal articles |
| US2400866A (en) * | 1941-11-08 | 1946-05-21 | United Drill And Tool Corp | Method of drawing metal stock |
| US2767835A (en) * | 1955-06-27 | 1956-10-23 | Lasalle Steel Co | Process of extruding steel |
| US2881107A (en) * | 1956-10-22 | 1959-04-07 | Lasalle Steel Co | Austempered, cold-finished steels |
| US2924544A (en) * | 1956-10-22 | 1960-02-09 | Lasalle Steel Co | Metallurgical process for cold-finishing steel |
Cited By (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3316068A (en) * | 1965-10-21 | 1967-04-25 | Lindsay Wire Weaving Co | Wire belt for use in paper making machines |
| US3459599A (en) * | 1966-10-17 | 1969-08-05 | United States Steel Corp | Method of thermomechanically annealing steel |
| US3523833A (en) * | 1967-03-14 | 1970-08-11 | Boehler & Co Ag Geb | Method of improving the properties of alloy steel castings |
| US3892602A (en) * | 1972-04-10 | 1975-07-01 | Bethlehem Steel Corp | As-worked, heat treated cold-workable hypoeutectoid steel |
| USRE29240E (en) * | 1973-05-09 | 1977-05-31 | Bethlehem Steel Corporation | As-worked, heat treated cold-workable hypoeutectoid steel |
| US5496425A (en) * | 1990-10-24 | 1996-03-05 | Consolidated Metal Products, Inc. | Cold formed high-strength steel structural members |
| US5236520A (en) * | 1990-10-24 | 1993-08-17 | Consolidated Metal Products, Inc. | High strength steel sway bars and method of making |
| US5330594A (en) * | 1990-10-24 | 1994-07-19 | Consolidated Metal Products, Inc. | Method of making cold formed high-strength steel parts |
| US5453139A (en) * | 1990-10-24 | 1995-09-26 | Consolidated Metal Products, Inc. | Method of making cold formed high-strength steel parts |
| US5454888A (en) * | 1990-10-24 | 1995-10-03 | Consolidated Metal Products, Inc. | Warm forming high-strength steel structural members |
| US5094698A (en) * | 1990-10-24 | 1992-03-10 | Consolidated Metal Products, Inc. | Method of making high strength steel parts |
| US5538566A (en) * | 1990-10-24 | 1996-07-23 | Consolidated Metal Products, Inc. | Warm forming high strength steel parts |
| US5704998A (en) * | 1990-10-24 | 1998-01-06 | Consolidated Metal Products, Inc. | Hot rolling high-strength steel structural members |
| US6325874B1 (en) | 1999-12-03 | 2001-12-04 | Consolidated Metal Products, Inc. | Cold forming flat-rolled high-strength steel blanks into structural members |
| US20030111143A1 (en) * | 2001-10-23 | 2003-06-19 | Consolidated Metal Products, Inc. | Flattened U-bolt and method |
| US6852181B2 (en) | 2001-10-23 | 2005-02-08 | Consolidated Metal Products, Inc. | Flattened U-bolt and method |
| US20080229893A1 (en) * | 2007-03-23 | 2008-09-25 | Dayton Progress Corporation | Tools with a thermo-mechanically modified working region and methods of forming such tools |
| US20090229417A1 (en) * | 2007-03-23 | 2009-09-17 | Dayton Progress Corporation | Methods of thermo-mechanically processing tool steel and tools made from thermo-mechanically processed tool steels |
| US8968495B2 (en) | 2007-03-23 | 2015-03-03 | Dayton Progress Corporation | Methods of thermo-mechanically processing tool steel and tools made from thermo-mechanically processed tool steels |
| US9132567B2 (en) | 2007-03-23 | 2015-09-15 | Dayton Progress Corporation | Tools with a thermo-mechanically modified working region and methods of forming such tools |
| US20110253826A1 (en) * | 2008-11-07 | 2011-10-20 | Polimeri Europa S.P.A. | Granulator blades with a high wear resistance and sharpening method thereof |
| RU2499638C1 (en) * | 2012-08-21 | 2013-11-27 | Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Национальный исследовательский технологический университет "МИСиС" | Strip hot rolling |
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