US3342058A - Roll for cold-rolling metallic sheet materials - Google Patents

Roll for cold-rolling metallic sheet materials Download PDF

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US3342058A
US3342058A US590437A US59043766A US3342058A US 3342058 A US3342058 A US 3342058A US 590437 A US590437 A US 590437A US 59043766 A US59043766 A US 59043766A US 3342058 A US3342058 A US 3342058A
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weight
roll
cold
chromium
alloy
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US590437A
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Nemoto Tadashi
Yaegashi Toshio
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Hitachi Ltd
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Hitachi Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/36—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.7% by weight of carbon
    • 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
    • Y10S203/00—Distillation: processes, separatory
    • Y10S203/05—Human waste

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  • the present invention relates to roll materials and more particularly to those for use in the making of hardened forging-steel rolls and has for its object to provide a roll material of the type which is highly improved in hardenability and wear resistance.
  • rolls of the Sendzimir mill for cold rolling have been made of 'a high-carbon high-chromium steel, which has heretofore been recommended, since the material when quenched from higher temperatures forms a martensite including chromium carbide of high hardness and thus has a substantial wear resistance.
  • Conventional roll materials such as highcarbon high-chromium alloy steels have been unable to meet this demand due to the lack of any satisfactory wear resistance.
  • the present invention is designed to furnish a roll material having an extraordinarily high wear resistance and a high hardenability.
  • a roll material comprising from 1.0% to 2.5% by weight of carbon, 3% to by weight of chromium, 0.5 to 8% by weight of molybdenum, 0.5% to 6% by weight of tungsten, 1.0% to 7.0% by weight of vanadium, not more than 0.5% by weight of silicon, and not more than 0.5 by weight of manganese, the balance being substantially iron.
  • less than l.0% by weight of carbon gives only insuflicient hardness and wear resistance while over 2.5% by weight of carbon impairs the hardenability of the alloy and reduces its ductility.
  • Chromium combines with carbon to form the carbides M C and M C which are very hard, and thus plays an important role in enhancing the wear resistance of the roll.
  • the weight percentage of chromium decreases below 3%, the amount of these carbides is rapidly reduced. In the range of over 10% by weight, an excess of primary crystals of chromium carbide appears in masses to cause exfoliation or firecracking during use of the roll. Therefore, the chromium percentage must be coordinated with the proportions of the other alloying elements.
  • Molybdenum also forms carbides, while a part thereof forms a solid solution in the base contributing to the strength and the heat resistance at elevated temperatures. This is important since, particularly in Sendzimir mills, the surface temperature of the rolls is momentarily raised to a substantial extent requiring a substantially high strength in the base of the roll material. This effect of the presence of molybdenum rapidly decreases as the weight percentage is reduced below 0.5 On the other hand, as the percentage increases, the amounts of molybdenum and 3,342,058 Patented Sept. 19, 1967 its carbide increase to give a highly improved wear resistance; however, in the range of over 8% both the workobility and the hardenability of the alloy steel are markedability and the hardenability of the alloy steel are marked- 1y reduced.
  • Tungsten has substantially the same effects as molybdenum except that it raises the wear resistance of the alloy to a much greater extent than molybdenum.
  • the tungsten content exceeds 6% by weight, the amount of tungsten forming a solid solution in the base is increased, thereby making the roll fragile.
  • vanadium is particular significant in the present invention.
  • chromium carbide in primary crystals is nonuniformly distributed in masses along the grain boundaries and such masses do .not disappear even by subsequent working or heat treatment of the material, causing exfoliation or firecracking in the use of the roll formed of such material.
  • vanadium if added together with chromium, forms a carbide during solidification in advance of chromium and in the form of minute spheroids to limit precipitation of the chromium carbide and thus prevents any nonuniform distribution of carbides in the alloy, as will clearly be observed in FIG. 2 in the accompanying drawmg.
  • FIG. 2 represents two micrographs x360 of one example of the alloy according to the invention, which comprises 2.2% by weight of C, 0.3% by weight of Si, 0.6% by weight of Mn, 5.1% by weight of Cr, 0.85% by weight of M0, 0.9% by weight of W, and 4.8% by weight of V, the rest being substantially iron.
  • FIG. 2a is a micrograph of a nonetched specimen oil-quenched at 950 C., showing clearly defined grains of vanadium carbide
  • FIG. 2b represents a micrograph of a specimen oilquenched 'at the same temperature and etched with a 10% solution of nitric acid, showing that the formation of chromium carbide is effectively suppressed.
  • Vanadium carbide is much harder than chromium carbide (about three times as hard as the latter) and thus is generally very effective in increasing the wear resistance of the roll.
  • vanadium carbide is much harder than chromium carbide (about three times as hard as the latter) and thus is generally very effective in increasing the wear resistance of the roll.
  • the effect of the addition of vanadium is reduced to about one half as its weight percentage is reduced below 1% while the presence of vanadium in percentages of over 7% reduces the workability and hardenability of the alloy to a substantial extent.
  • FIG. 1 graphically illustrates the relationship between the hardness and the quenching temperature of the two materials
  • Table 1 which includes data comparing the two materials with respect to their wear resistance as expressed in terms of their resistance to grinding.
  • the high-carbon high-chromium steel selected as a typical example of conventional roll material comprised 2.1% by weight of C, 12.5% by weight of Cr, 0.85% by weight of Mo, and 0.88% by weight of V, the balance being substantially iron.
  • the solid line represents the hardness of the alloy of the invention while the dotted line represents that of the conventional high-carbon high-chromium steel.
  • the alloy of the invention has an optimum quenching temperature lower than that of the high-carbon high-chromium steel, thereby facilitating the hardening procedure to that extent. It has been found in this testing that the alloyof the invention has a satisfactory self-hardenability and exhibits excellent mechanical properties due to its finegrained structure as seen in the micrographs of FIG. 2.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)

Description

Sept. 19, 1967 TADASHI NEMOTO E AL 3,342,058
ROLL FOR COLD-ROLLING METALLIC SHEET MATERIALJS Original Filed March 25, 1963 2 Sheets-Sheet 1 Quenching femperan/re ("6) Fl 3 g L T InvErrToRs Tsaag'fi nemo o ashio Vaeg aQfi Sept. 19,1967' DASH-MEMO, m 3,342,058
ROLL FOR COLD-ROLLING METALTJI'C SHEET MATERIALS Original Filed March 25, 1963 2 Sheets-Sheet z Hg 20 Hg 20 Non-etching Efch/ry M712 /0% n/fr/c ac/a' M'lcmsrrucm or" me invent/Va alloy 360) (0//'quenche0 0r 950'6 BY QuL 0 417,
Tadashi Nemoto, Takahagi-shi,
United States Patent 3,342,058 ROLL FOR COLD-ROLLING METALLIC SHEET MATERIALS and Toshio Yaegashi, Hitachi-shi, Japan, assignors to Hitachi, Ltd., Tokyo, Japan, a corporation of Japan Continuation of application Ser. No. 267,757, Mar.
25, 1963. This application Oct. 28, 1966, Ser. No.
590,437 Claims priority, application Japan, Mar. 26, 1962,
37/ 11,036 2 Claims. (Cl. 72-365) This application is a continuation of application Ser. No. 267,757 filed Mar. 25, 1963, now abandoned.
The present invention relates to roll materials and more particularly to those for use in the making of hardened forging-steel rolls and has for its object to provide a roll material of the type which is highly improved in hardenability and wear resistance.
Cutomarily, rolls of the Sendzimir mill for cold rolling have been made of 'a high-carbon high-chromium steel, which has heretofore been recommended, since the material when quenched from higher temperatures forms a martensite including chromium carbide of high hardness and thus has a substantial wear resistance. Most recently, however, the demand for improvements in dimension-a1 accuracy and surface luster of rolled steel sheets has been increasing. Conventional roll materials such as highcarbon high-chromium alloy steels have been unable to meet this demand due to the lack of any satisfactory wear resistance.
In View of the above difiiculty, the present invention is designed to furnish a roll material having an extraordinarily high wear resistance and a high hardenability.
According to the present invention, there is provided a roll material comprising from 1.0% to 2.5% by weight of carbon, 3% to by weight of chromium, 0.5 to 8% by weight of molybdenum, 0.5% to 6% by weight of tungsten, 1.0% to 7.0% by weight of vanadium, not more than 0.5% by weight of silicon, and not more than 0.5 by weight of manganese, the balance being substantially iron.
Composition limits for each of the alloying elements will now be detailed.
Carbon forms carbides in the alloy, which are critically important for obtaining a desired wear resistance. However, less than l.0% by weight of carbon gives only insuflicient hardness and wear resistance while over 2.5% by weight of carbon impairs the hardenability of the alloy and reduces its ductility.
Chromium combines with carbon to form the carbides M C and M C which are very hard, and thus plays an important role in enhancing the wear resistance of the roll. However, as the weight percentage of chromium decreases below 3%, the amount of these carbides is rapidly reduced. In the range of over 10% by weight, an excess of primary crystals of chromium carbide appears in masses to cause exfoliation or firecracking during use of the roll. Therefore, the chromium percentage must be coordinated with the proportions of the other alloying elements.
Molybdenum also forms carbides, while a part thereof forms a solid solution in the base contributing to the strength and the heat resistance at elevated temperatures. This is important since, particularly in Sendzimir mills, the surface temperature of the rolls is momentarily raised to a substantial extent requiring a substantially high strength in the base of the roll material. This effect of the presence of molybdenum rapidly decreases as the weight percentage is reduced below 0.5 On the other hand, as the percentage increases, the amounts of molybdenum and 3,342,058 Patented Sept. 19, 1967 its carbide increase to give a highly improved wear resistance; however, in the range of over 8% both the workobility and the hardenability of the alloy steel are markedability and the hardenability of the alloy steel are marked- 1y reduced.
Tungsten has substantially the same effects as molybdenum except that it raises the wear resistance of the alloy to a much greater extent than molybdenum. However, as the tungsten content exceeds 6% by weight, the amount of tungsten forming a solid solution in the base is increased, thereby making the roll fragile.
The use of vanadium is particular significant in the present invention. In most of the high-carbon high-chromium steels previously used, chromium carbide in primary crystals is nonuniformly distributed in masses along the grain boundaries and such masses do .not disappear even by subsequent working or heat treatment of the material, causing exfoliation or firecracking in the use of the roll formed of such material. Experiments have shown, however, that vanadium, if added together with chromium, forms a carbide during solidification in advance of chromium and in the form of minute spheroids to limit precipitation of the chromium carbide and thus prevents any nonuniform distribution of carbides in the alloy, as will clearly be observed in FIG. 2 in the accompanying drawmg.
FIG. 2 represents two micrographs x360 of one example of the alloy according to the invention, which comprises 2.2% by weight of C, 0.3% by weight of Si, 0.6% by weight of Mn, 5.1% by weight of Cr, 0.85% by weight of M0, 0.9% by weight of W, and 4.8% by weight of V, the rest being substantially iron. FIG. 2a, is a micrograph of a nonetched specimen oil-quenched at 950 C., showing clearly defined grains of vanadium carbide, while FIG. 2b, represents a micrograph of a specimen oilquenched 'at the same temperature and etched with a 10% solution of nitric acid, showing that the formation of chromium carbide is effectively suppressed. Vanadium carbide is much harder than chromium carbide (about three times as hard as the latter) and thus is generally very effective in increasing the wear resistance of the roll. However, it is noted that the effect of the addition of vanadium is reduced to about one half as its weight percentage is reduced below 1% while the presence of vanadium in percentages of over 7% reduces the workability and hardenability of the alloy to a substantial extent.
The advantages of the roll material of the invention over the high-carbon high-chromium steel conventionally used as a roll material will be evident from FIG. 1, which graphically illustrates the relationship between the hardness and the quenching temperature of the two materials, and Table 1, which includes data comparing the two materials with respect to their wear resistance as expressed in terms of their resistance to grinding. The composition of the roll material according to this invention forth hereinbefore in connection with FIG. 2. On the other hand, the high-carbon high-chromium steel selected as a typical example of conventional roll material comprised 2.1% by weight of C, 12.5% by weight of Cr, 0.85% by weight of Mo, and 0.88% by weight of V, the balance being substantially iron. In FIG. 1, the solid line represents the hardness of the alloy of the invention while the dotted line represents that of the conventional high-carbon high-chromium steel. As observed in this figure, the alloy of the invention has an optimum quenching temperature lower than that of the high-carbon high-chromium steel, thereby facilitating the hardening procedure to that extent. It has been found in this testing that the alloyof the invention has a satisfactory self-hardenability and exhibits excellent mechanical properties due to its finegrained structure as seen in the micrographs of FIG. 2.
TABLE 1 Weight, gr. Weight ratio, B 100% A Specific wear resistance Material of specimen Material removed Grit dislodged High-C high-Or steel.-. Inventive alloy As apparent from this table, the alloy of the invention exhibits a notably reduced grindability compared with the conventional roll material and is duly expected to have a wear resistance nearly three times as high as that of the latter. Actual use of rolls formed of the alloy of the invention in a rolling mill for non-ferrous alloys and in a small-sized Sendzimir mill has demonstrated the fact that the alloy gives a highly improved roll performance compared with any of the conventional roll materials.
We claim:
1. In a process of cold-rolling metals by means of a rolling mill having rolls which contact the metal, the improvement in said process comprising contacting said metals with said rolls, said rolls consisting essentially of 4 1.0 to 2.5% by weight of carbon, 3 to 10% by Weight of chromium, 0.5 to 8% by weight of molybdenum, 0.5 to 6% by Weight of tungsten, 1.0 to 7% by weight of vanadium, not more than 0.5% by weight of silicon, not more than 0.6% by weight of manganese, the balance being substantially iron and a small amount of impurities.
2. In a process of cold-rolling metals by means of a rolling mill having rolls which contact the metal, the improvement in said process comprising contacting said metals with said rolls, said rolls consisting essentially of 2.2% by weight of carbon, 0.3% by weight of silicon, 0.6% by weight of manganese, 5.1% by weight of chromium, 0.85% by Weight of molybdenum, 0.9% by weight of tungsten, 4.8% by weight of vanadium, and the balance being substantially iron.
References Cited UNITED STATES PATENTS 2,174,286 9/1939 Gill 126 2,736,650 2/1956 Grimshaw 75-126 2,867,532 l/1959 Payseen 75-l26 2,983,601 5/1961 Fletcher 75-126 2,996,376 8/1961 Nehrenberg 75126 OTHER REFERENCES Roberts et al.: Tool Steels, 3rd ed., Apr. 16, 1962, pub. by the American Society for Metals, pp. 237 and 23 8,
HYLAND BIZOT, Primary Examiner.
P. WEINSTEIN, Assistant Examiner.

Claims (1)

1. IN A PROCESS OF COLD-ROLLING METALS BY MEANS OF A ROLLING MILL HAVING ROLLS WHICH CONTACT THE METAL, THE IMPROVEMENT IN SAID PROCESS COMPRISING CONTACTING SAID METALS WITH SAID ROLLS, SAID ROLLS CONSISTING ESSENTIALLY OF 1.0 TO 2.5% BY WEIGHT OF CARBON, 3 TO 10% BY WEIGHT OF CHRONIUM, 0.5 TO 8% BY WEIGHT OF MOLYDENUM, 0.5 TO 6% BY WEIGHT OF TUNGSTEN, 1.0 TO 7% BY WEIGHT OF VANADIUM, NOT MORE THAN 0.5% BY WEIGHT OF SILICON, NOT MORE THAN 0.6% BY WEIGHT OF MANGANESE, THE BALANCE BEING SUBSTANTIALLY IRON AND A SMALL AMOUNT OF IMPURITIES.
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4875415A (en) * 1971-11-10 1973-10-11
FR2345233A1 (en) * 1976-03-22 1977-10-21 Industrial Materials Tech Crack-resistant rolls for shaping metal - composed of compacted metal powder on sheathed tubular core
US4106319A (en) * 1977-03-11 1978-08-15 Southwire Company Apparatus for hot-rolling non-ferrous metals
US4193823A (en) * 1977-03-11 1980-03-18 Southwire Company Rolls for hot-rolling non-ferrous metals and method of making
EP0178022A1 (en) * 1984-10-08 1986-04-16 S.A. des Fonderies J. Marichal, Ketin & Cie. Roll made from two metals for reduction or finishing stands in a hot strip mill
EP0252828A1 (en) * 1986-07-11 1988-01-13 Chavanne-Ketin Composite steel roll for a hot rolling mill
EP0275475A1 (en) * 1986-12-30 1988-07-27 Uddeholm Tooling Aktiebolag Tool steel
USRE35052E (en) * 1979-11-13 1995-10-03 Forcast International Method for hot rolling metal strip with composite metal rolls
EP2455180A1 (en) * 2010-11-17 2012-05-23 Cetto Maschinenbau Gmbh & Co. Kg. Iron-chromium molybdenum manganese alloy, use of same, method for producing this alloy, a roller for a roller assembly with a surface composed of this alloy and a roller for a roller assembly with a surface produced according to the method used to produce this alloy

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2174286A (en) * 1939-02-21 1939-09-26 Vanadium Alloys Steel Co Ferrous alloy
US2736650A (en) * 1953-06-08 1956-02-28 Firth Sterling Inc Low alloy high speed steel
US2867532A (en) * 1957-01-16 1959-01-06 Crucible Steel Co America Wear resistant alloy steel
US2983601A (en) * 1954-09-14 1961-05-09 Latrobe Steel Co Ferrous alloys and articles made therefrom
US2996376A (en) * 1961-04-06 1961-08-15 Crucible Steel Co America Low alloy steel having high hardness at elevated temperatures

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2174286A (en) * 1939-02-21 1939-09-26 Vanadium Alloys Steel Co Ferrous alloy
US2736650A (en) * 1953-06-08 1956-02-28 Firth Sterling Inc Low alloy high speed steel
US2983601A (en) * 1954-09-14 1961-05-09 Latrobe Steel Co Ferrous alloys and articles made therefrom
US2867532A (en) * 1957-01-16 1959-01-06 Crucible Steel Co America Wear resistant alloy steel
US2996376A (en) * 1961-04-06 1961-08-15 Crucible Steel Co America Low alloy steel having high hardness at elevated temperatures

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4875415A (en) * 1971-11-10 1973-10-11
JPS54173011U (en) * 1971-11-10 1979-12-06
FR2345233A1 (en) * 1976-03-22 1977-10-21 Industrial Materials Tech Crack-resistant rolls for shaping metal - composed of compacted metal powder on sheathed tubular core
US4106319A (en) * 1977-03-11 1978-08-15 Southwire Company Apparatus for hot-rolling non-ferrous metals
DE2810186A1 (en) * 1977-03-11 1978-09-14 Southwire Co ROLLING MILL AND ROLL FOR HOT ROLLING NON-FERROUS METALS AND METHOD FOR PRODUCING THE ROLL
US4193823A (en) * 1977-03-11 1980-03-18 Southwire Company Rolls for hot-rolling non-ferrous metals and method of making
USRE35052E (en) * 1979-11-13 1995-10-03 Forcast International Method for hot rolling metal strip with composite metal rolls
EP0178022A1 (en) * 1984-10-08 1986-04-16 S.A. des Fonderies J. Marichal, Ketin & Cie. Roll made from two metals for reduction or finishing stands in a hot strip mill
EP0252828A1 (en) * 1986-07-11 1988-01-13 Chavanne-Ketin Composite steel roll for a hot rolling mill
FR2601268A1 (en) * 1986-07-11 1988-01-15 Chavanne Ketin COMPOSITE STEEL WORKING CYLINDER FOR HOT TRAIN.
EP0275475A1 (en) * 1986-12-30 1988-07-27 Uddeholm Tooling Aktiebolag Tool steel
EP2455180A1 (en) * 2010-11-17 2012-05-23 Cetto Maschinenbau Gmbh & Co. Kg. Iron-chromium molybdenum manganese alloy, use of same, method for producing this alloy, a roller for a roller assembly with a surface composed of this alloy and a roller for a roller assembly with a surface produced according to the method used to produce this alloy

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