WO2014132628A1 - ロール外層材および熱間圧延用複合ロール - Google Patents
ロール外層材および熱間圧延用複合ロール Download PDFInfo
- Publication number
- WO2014132628A1 WO2014132628A1 PCT/JP2014/000985 JP2014000985W WO2014132628A1 WO 2014132628 A1 WO2014132628 A1 WO 2014132628A1 JP 2014000985 W JP2014000985 W JP 2014000985W WO 2014132628 A1 WO2014132628 A1 WO 2014132628A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- roll
- outer layer
- hot rolling
- layer material
- content
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
- C22C37/06—Cast-iron alloys containing chromium
-
- 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
-
- 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
- B21B27/02—Shape or construction of rolls
- B21B27/03—Sleeved rolls
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
- B32B15/011—Layered products comprising a layer of metal all layers being exclusively metallic all layers being formed of iron alloys or steels
-
- 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
- C21D5/00—Heat treatments of cast-iron
-
- 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/38—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for roll bodies
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
- C22C37/10—Cast-iron alloys containing aluminium or silicon
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/004—Dispersions; Precipitations
Definitions
- the present invention is a roll outer layer material that constitutes an outer layer of a composite roll for hot rolling for a hot roll finishing mill of a steel sheet (composite roll for hot roll). And a hot-rolling composite roll having an outer layer made of the roll outer layer material.
- the use environment of rolls has become more severe with the progress of hot rolling technology for steel sheets.
- the production of steel plates with a large rolling load such as high-strength steel plates and thin-walled products has increased. For this reason, surface roughness and chipping due to fatigue of the rolling surface of the hot rolling roll often occur.
- the roll for hot rolling here means the work roll used for finish rolling.
- Patent Document 1 and Patent Document 2 propose a high-speed roll outer layer material for hot rolling.
- the roll outer layer material for hot rolling described in Patent Document 1 has C: 1.5 to 3.5%, Ni: 5.5% or less, Cr: 5.5 to 12.0%, Mo: 2. 0 to 8.0%, V: 3.0 to 10.0%, Nb: 0.5 to 7.0%.
- the roll outer layer material for hot rolling described in Patent Document 1 satisfies Nb and V, the contents of Nb, V and C satisfy a specific relationship, and the ratio of Nb and V is within a specific range. To be contained.
- the roll outer layer material for hot rolling described in Patent Document 2 has C: 1.5 to 3.5%, Cr: 5.5 to 12.0%, Mo: 2.0 to 8.0% V: 3.0 to 10.0%, Nb: 0.5 to 7.0%.
- the roll outer layer material for hot rolling described in Patent Document 2 includes C, Nb and V, the contents of Nb, V and C satisfy a specific relationship, and the ratio of Nb and V is specific. It contains so that it may become in the range. Thereby, even if a centrifugal casting method is applied, segregation of hard carbides in the outer layer material is suppressed, and the wear resistance and crack resistance of the hot rolling roll are improved. For this reason, it is said that the technique described in Patent Document 2 contributes to efficient hot rolling.
- Patent Document 3 discloses that C: 2.2 to 2.6%, Cr: 5.0 to 8.0%, Mo: 4.4 to 6.0%, V: 5 .3 to 7.0%, Nb: 0.6 to 1.3%, and the contents of C, Mo, V, and Nb are set so that Mo + V and C ⁇ 0.24V ⁇ 0.13Nb are within a specific range.
- a composite cast roll made by centrifugal casting has been proposed. This centrifugally cast composite roll is said to be excellent in fatigue resistance (fatigue ⁇ resistance) of the roll surface layer in a hot rolling environment.
- the present invention solves such a problem of the prior art, and the fatigue resistance of the surface layer (here, the ability to suppress fatigue damage such as rough skin and chipping that occurs in the roll surface part by hot rolling is called "fatigue resistance”.
- Excellent roll outer layer material for hot rolling, and a composite roll made by centrifugal casting for hot rolling formed by using the outer layer material of the roll (composite-roll-for-hot-rolling-produced-through-centrifugal-casting) (this specification)
- the purpose is to provide a composite roll for hot rolling (sometimes referred to as “composite roll for hot roll”).
- the present inventors conduct a detailed observation and investigation on the surface of the roll having rough skin or missing by hot rolling (hot rolling). An important finding has been obtained that the roll surface layer breaks due to cracks that have occurred and propagated in coarse carbides exceeding 50 ⁇ m. Therefore, the present inventors have determined how to control the carbide morphology to improve fatigue resistance, and to determine the damage form of carbide on the outer layer surface of the composite roll for hot rolling. We studied diligently by investigating morphology) in detail.
- the inventors of the present invention have further intensively studied to technically realize a remarkable improvement in fatigue resistance, and have clarified the quantitative optimum range of coarse carbides and fine carbides.
- a molten metal having a composition composed of Fe and unavoidable impurities is produced in a high-frequency furnace, and a ring-shaped roll material corresponding to the roll outer layer material (outer diameter: 250 mm ⁇ , (Width: 75 mm, wall thickness: 55 mm) was cast by centrifugal casting.
- the casting temperature was 1450 to 1530 ° C.
- the centrifugal force was 180 G in gravity multiple. Further, after casting, quenching from 1050 ° C. and tempering at 530 to 560 ° C. were performed a plurality of times, and the shore hardness of the ring-shaped roll material was set to HS 80 to 87.
- Hot rolling fatigue test specimens (outer diameter 60mm ⁇ , wall thickness 10mm) are collected from the obtained ring-shaped roll material to reproduce the fatigue resistance of hot roll work rolls (work roll for hot rolling)
- a hot rolling fatigue test (test described in Japanese Patent Application Laid-Open No. 2010-101752), which was shown to be well evaluated, was performed. Note that the hot rolling fatigue test piece has notches (depth t: 1.2 mm, circumferential length L: 0.8 mm) as shown in FIG. .Introduced by electric sparking forming method (wire cutting) using 2mm ⁇ wire. In addition, 1.2C chamfering was applied to the end of the rolling contact surface of the hot rolling fatigue test piece.
- the hot rolling fatigue test is a two-disk sliding rolling fatigue method (slip rolling rolling fatigue type) of a notched specimen (hot rolled fatigue testing specimen) and a heated counterpart material. ) That is, as shown in FIG. 3, the test piece (hot rolling fatigue test piece) was rotated at 700 rpm while being cooled with water, and the rotating test piece was heated to 810 ° C. (material: S45C, outer diameter: While being pressed with a load of 980 N at 190 mm ⁇ and width: 15 mm, rolling was performed at a slip ratio of 9%. Roll until the two notches introduced to the hot rolling fatigue test piece break, break the rolling notch until each notch breaks, and calculate the average value for the hot rolling fatigue life. (fatigue life).
- FIG. 1 shows the hot rolling fatigue life (hot rolling fatigue means hot rolling fatigue. Therefore, the hot rolling fatigue property means hot rolling fatigue life) and the above-mentioned coarse carbide and fine carbide.
- FIG. 2 shows the relationship between the hot rolling fatigue life and (Cr (%) + Mo (%)) / V (%).
- FIG. 1 shows that the hot rolling fatigue life is remarkably improved as the amount of fine carbide having a circle equivalent diameter of 3 to 30 ⁇ m increases.
- the hot rolling fatigue life is significantly reduced even if the amount of fine carbide having an equivalent circle diameter of 3 to 30 ⁇ m is large. Yes.
- the amount of coarse carbide having an equivalent circle diameter exceeding 50 ⁇ m is reduced. It is clear that the amount of fine carbide having an equivalent circle diameter of 3 to 30 ⁇ m is required to be 500 to 2500 pieces / mm 2 when the number is 20 pieces / mm 2 or less.
- the hot rolling fatigue life of the roll material for hot rolling can be simply evaluated.
- the roll carbide structure was quantified by the following method. First, the cut surface of the sample cut from an arbitrary position in the range of 20 to 25 mm in the depth direction from the outer surface at the initial stage of use of the roll was finished to mirror polishing. Next, the polished cut surface was strongly corroded with natal so that the carbides look white and the base looks black with an optical microscope. The carbide morphology of the cut surface was then examined using an image analysis device at a microscope magnification of 100 (200 magnification on the monitor). The number of coarse carbides having an equivalent circle diameter of 50 ⁇ m or more and the number of fine carbides having an equivalent circle diameter of 3 to 30 ⁇ m were used as quantitative values. The observed field of view area is 9 mm 2 .
- the present invention has been completed based on the above findings. That is, the gist of the present invention is as follows.
- composition further contains one or more of Al: 0.001 to 0.05% and REM: 0.001 to 0.03% by mass% in [2]
- a composite roll for hot rolling in which an outer layer and an inner layer are welded and integrated, wherein the outer layer is made of the roll outer layer material described in [1] to [3]. roll.
- the composite roll for hot rolling of the present invention is used in a severe hot rolling environment where a high rolling load is applied or a large amount of continuous rolling occurs, the roll surface such as rough surface and surface layer chipping (surface cracking) Hot-rolling fatigue damage (fatigue damage due to hot rolling) is less likely to occur. Therefore, according to the present invention, it is possible to achieve both a significant improvement in surface quality and an improvement in roll life.
- the present invention it is possible to easily manufacture a hot-rolling composite roll having significantly improved fatigue resistance. Therefore, according to the present invention, it is possible to achieve all of the productivity improvement of the hot-rolled steel sheet, the remarkable improvement of the surface quality, and the improvement of the roll life.
- FIG. 1 is a diagram showing the relationship between the hot rolling fatigue life in the hot rolling fatigue test, the area ratio of granular carbides, and the number of coarse carbides per unit area.
- FIG. 2 is a diagram showing the relationship between the hot rolling fatigue life and (Cr (%) + Mo (%)) / V (%) in the hot rolling fatigue test.
- Fig. 3 shows the configuration of the testing machine used in the hot rolling fatigue test, the outer periphery of the test piece for hot rolling fatigue test (fatigue test piece), and the test piece for hot rolling fatigue test (fatigue test piece) It is explanatory drawing which shows typically the shape and dimension of the notch introduced into the surface.
- the roll outer layer material of the present invention is made by centrifugal casting, and can be used as it is as a ring roll or a sleeve roll. Moreover, the roll outer layer material of the present invention is applied as an outer layer material of a composite roll for hot rolling suitable for hot finish rolling.
- the composite roll for hot rolling according to the present invention comprises an outer layer formed by centrifugal casting and an inner layer welded and integrated with the outer layer. An intermediate layer may be disposed between the outer layer and the inner layer. That is, instead of the inner layer welded and integrated with the outer layer, an intermediate layer welded and integrated with the outer layer and an inner layer welded and integrated with the intermediate layer may be used.
- the outer layer and the inner layer are welded and integrated through the intermediate layer.
- the inner layer is preferably produced by static casting.
- the composition of the inner layer and the intermediate layer is not particularly limited, but the inner layer is preferably made of nodular graphite cast iron and the intermediate layer is made of a high carbon material having C: 1.5 to 3% by mass.
- C 2.4 to 2.9% C increases the hardness of the base phase by solid solution and combines with the carbide-forming element to form hard carbide, thereby improving the wear resistance of the roll outer layer material.
- the rolling use characteristic means a necessary characteristic as a rolling roll outer layer material that combines the lubricity and fatigue resistance of the roll outer layer material surface during rolling. If the C content is less than 2.4%, the amount of carbide is insufficient, the frictional force on the surface of the roll outer layer material increases during rolling, and rolling may become unstable. On the other hand, the content of C exceeding 2.9% may excessively increase the amount of carbides to form connected coarse carbides, thereby reducing fatigue resistance. Therefore, the C content is preferably limited to a range of 2.4 to 2.9%. In the case where Al and REM are not contained, the C content is preferably limited to a range of 2.7 to 2.9%.
- Si 0.2 to 1.0%
- Si is an element that acts as a deoxidizing agent and improves the casting performance of the molten metal.
- the Si content is desirably 0.2% or more. Further, even if the Si content exceeds 1.0%, the effect is saturated and an effect commensurate with the content cannot be expected, which is economically disadvantageous by the increase in cost due to the increase in the Si content. Therefore, the Si content is preferably limited to a range of 0.2 to 1.0%.
- Mn 0.2 to 1.0%
- Mn has an effect of fixing S as MnS and detoxifying it.
- Mn is an element that has an effect of improving the hardenability by dissolving in a matrix.
- the Mn content is preferably 0.2% or more.
- the Mn content is preferably limited to a range of 0.2 to 1.0%.
- Cr 4.0 to 7.5% Cr combines with C to form mainly eutectic carbide, improving wear resistance and reducing the frictional force between the steel sheet and the outer roll surface during rolling, It is an element that acts to reduce damage and stabilize rolling. Furthermore, in this invention, Cr has the effect
- Mo 4.0-6.5%
- Mo is an element that combines with C to form a hard carbide and improves wear resistance. Mo dissolves in hard MC-type carbides to strengthen the carbides and also dissolves in eutectic carbides to increase the fracture resistance of these carbides. Through such an action, Mo improves the fatigue resistance of the outer roll layer material. In order to obtain such an effect, the Mo content is preferably set to 4.0% or more. On the other hand, if the Mo content exceeds 6.5%, hard and brittle carbides mainly composed of Mo may be generated and the fatigue resistance may be lowered. Therefore, the Mo content is preferably limited to a range of 4.0 to 6.5%.
- V 5.3 to 7.0%
- V is an important element in the present invention in order to have both wear resistance and fatigue resistance.
- V forms extremely hard granular carbide (MC type carbide), improves wear resistance, and effectively acts to sever coarse eutectic carbide and dispersely crystallize. It is an element that significantly improves the fatigue resistance of the material. Such an effect becomes remarkable when the content of V is set to 5.3% or more.
- the V content exceeds 7.0%, the MC type carbide may be coarsened and the centrifugal casting segregation of the MC type carbide may be promoted. In this case, in the hot rolling roll, Various characteristics become unstable. Therefore, the V content is preferably limited to a range of 5.3 to 7.0%.
- Nb 0.5 to 3.0% Nb improves the fatigue resistance through the effect of increasing the fracture resistance by coexisting with Mo by solid-dissolving in the granular MC-type carbide and strengthening the MC-type carbide.
- Nb is an element which has an effect
- Nb has the effect
- the content of Nb exceeding 3.0% may promote the growth of MC type carbides in the molten metal and promote the segregation of carbides during centrifugal casting. Therefore, the Nb content is preferably limited to a range of 0.5 to 3.0%. More preferably, it is 0.5 to 2.0%.
- Al and REM both have the effect of strongly promoting the formation of granular carbides, and have the effect of increasing the amount of fine carbides. is there. For this reason, Al and REM impart excellent fatigue resistance to the roll outer layer material.
- REM is a misch metal that is a mixture of two or more rare earth elements. If it is difficult to analyze all the rare earth elements, the REM content may be twice the Ce analysis value. Good.
- the balance other than the above components is composed of Fe and inevitable impurities.
- inevitable impurities include P: 0.05% or less, S: 0.05% or less, N: 0.06% or less, B: 0.03% or less, and Ni: 0.2% or less.
- the P content is 0.05% or less.
- S exists as sulfide inclusions and lowers the material, it is preferable to reduce the S content as much as possible. However, it is acceptable if the S content is 0.05% or less.
- N is mixed in an amount of about 0.01 to 0.06% for normal dissolution.
- the N content of this level does not affect the effects of the present invention.
- the N content is preferably limited to less than 0.05%.
- B is an element mixed from scrap, which is a raw material, such as raw metal for melting metal, casting flux, and the like, and has an action of dissolving in the carbide and weakening the carbide.
- it is preferable to reduce the B content as much as possible. However, if the content of B is 0.03% or less, the effect of the present invention is not significantly adversely affected and is acceptable.
- Ni is an element mixed from scrap, which is a melting raw material, affects the hardenability of the roll outer layer material, and generates variations in hardness and residual stress after heat treatment. In the present invention, it is preferable to reduce the Ni content as much as possible. However, if the Ni content is 0.2% or less, it is acceptable in the production of rolls.
- the roll outer layer material is manufactured by a low-cost centrifugal casting method with low energy costs.
- the molten outer layer material composition described above is applied to a rotating mold in which a refractory mainly composed of zircon or the like is coated on the inner surface with a thickness of 1 to 5 mm so as to have a predetermined thickness.
- the rotational speed of the casting mold is preferably adjusted so that the gravity multiple applied to the outer surface of the roll is in the range of 120 to 220G.
- the outer layer layer material is solidified during solidification or completely solidified, and then the molten metal having the intermediate layer composition is poured and centrifugally cast while rotating the mold.
- the mold rotation and stand the mold After the outer layer or the intermediate layer is completely solidified, it is preferable to stop the mold rotation and stand the mold, and then statically cast the inner layer material to form a composite roll. Thereby, the inner surface side of the roll outer layer material is redissolved to form a composite roll in which the outer layer and the inner layer, or the outer layer and the intermediate layer, and the intermediate layer and the inner layer are welded and integrated.
- spheroidal graphite cast iron excellent in castability and mechanical properties, worm-like graphite cast iron (VC cast iron), or the like for the inner layer to be statically cast.
- the outer layer and the inner layer are integrally welded, so that the component of the outer layer material is mixed in the inner layer by about 1 to 8%.
- carbide forming elements such as Cr and V contained in the outer layer material are mixed into the inner layer, the inner layer is weakened. For this reason, it is preferable to suppress the mixing rate of the outer layer component into the inner layer to less than 6%.
- the intermediate layer when forming the intermediate layer, it is preferable to use graphite steel, high-carbon steel, hypoeutectic cast iron, or the like as the intermediate layer material.
- the intermediate layer and the outer layer are integrally welded in the same manner, and the outer layer component is mixed in the intermediate layer in the range of 10 to 95%. From the viewpoint of suppressing the amount of the outer layer component mixed into the inner layer, it is important to reduce the amount of the outer layer component mixed into the intermediate layer as much as possible.
- the composite roll for hot rolling of the present invention is preferably subjected to heat treatment after casting.
- the heat treatment is preferably a treatment in which heating to 950 to 1150 ° C. and air cooling or blast air cooling (air blast cooling), and further heating and holding at 450 to 600 ° C. followed by cooling are performed once or more.
- the preferable hardness of the composite roll for hot rolling of the present invention is 79 to 88 HS, and more preferable hardness is 80 to 87 HS. It is recommended to adjust the heat treatment after casting so that such hardness can be secured stably.
- the melt of the roll outer layer material composition shown in Table 1 was melted in a high-frequency furnace (furnace) and subjected to centrifugal casting to obtain a ring-shaped test material (ring roll; outer diameter: 250 mm ⁇ , width: 75 mm, wall thickness: 55 mm) It was.
- the casting temperature was 1430 to 1550 ° C.
- the centrifugal force was 180 G as a multiple of gravity.
- quenching from 1050 ° C. and tempering from 540 to 560 ° C. were performed, and the hardness was adjusted to 79 to 86 HS.
- Microstructure observation specimens and fatigue specimens were collected from the obtained ring-shaped test materials, and microstructure observation (of observation microstructure) and hot rolling fatigue tests were performed.
- the test method was as follows.
- Hot rolling fatigue test A fatigue test piece (outer diameter 60 mm ⁇ , wall thickness 10 mm, chamfered) having the shape shown in FIG. 3 was collected from the obtained ring-shaped test material.
- electrical discharge machining using notches depth t: 1.2 mm, circumferential length L: 0.8 mm as shown in FIG. It was introduced by the (wire cut) method.
- the hot rolling fatigue test is performed by a two-disk sliding rolling method of a hot rolling fatigue test piece and a counterpart material, and the hot rolling fatigue test piece is rotated at 700 rpm while being cooled with water.
- the mating piece material: S45C, outer diameter: 190 mm ⁇ , width: 15 mm
- the mating piece heated to 810 ° C. was rolled to the rotating test piece at a slip ratio of 9% while being pressed with a load of 980 N.
- the two rolling notches introduced into the hot rolling fatigue test piece were rolled until they broke, the rolling rotation speed until each notch broke was determined, and the average value was calculated as the hot rolling fatigue life. did.
- this hot rolling fatigue life exceeded 300,000 times, the hot rolling fatigue life was considered excellent.
- the hot rolling fatigue life is remarkably improved as compared with the comparative example.
- Comparative Examples M, R, S, U, and V there are few fine carbides having an equivalent circle diameter of 3 to 30 ⁇ m, and the hot rolling fatigue life is deteriorated. Further, in Comparative Examples L, M, N, P, Q, S, and T, there is an excessive amount of coarse carbide having an equivalent circle diameter exceeding 50 ⁇ m. Therefore, cracks propagate through the coarse carbide and the hot rolling fatigue characteristics are remarkable. Declined. In Comparative Example W, the number of fine carbides excessively increased, cracks propagated to the adjacent carbides, and the hot rolling fatigue life was significantly reduced.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Geometry (AREA)
- Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
Abstract
Description
記
1.5 ≦ (Cr+Mo)/V ≦ 2.4 ・・・(1)
ここで、Cr、Mo、V:各元素の含有量(質量%)
Cは、固溶して基地(base phase)の硬さを増加させるとともに、炭化物形成元素(carbide-forming element)と結合し硬質炭化物を形成し、ロール外層材の耐摩耗性を向上させる作用を有する。C含有量に応じて圧延使用特性に影響を及ぼす炭化物の形態が変化する。ここで、圧延使用特性とは、圧延時のロール外層材表面の潤滑性と耐疲労性を複合した、圧延ロール外層材としての必要特性を意味する。C含有量が2.4%未満では、炭化物量が不足し、圧延時にロール外層材表面の摩擦力が増加し圧延が不安定となる場合がある。一方、2.9%を超えるCの含有は、炭化物量を過度に増加させ、連結した粗大炭化物を形成して、耐疲労性を低下させる場合がある。このため、Cの含有量は2.4~2.9%の範囲に限定することが好ましい。また、Al、REMを含有しない場合は、Cの含有量は2.7~2.9%の範囲に限定することが好ましい。
Siは、脱酸剤(deoxidizing agent)として作用するとともに、溶湯の鋳造性(casting performance)を向上させる元素である。本発明ではSiの含有量を0.2%以上にすることが望ましい。また、Siの含有量が1.0%を超えても効果が飽和し含有量に見合う効果が期待できなくなり、Siの含有量を増加させることによる費用増加の分だけ経済的に不利となる。このため、Siの含有量は0.2~1.0%の範囲に限定することが好ましい。
Mnは、SをMnSとして固定し、無害化する作用を有する。また、Mnは、基地に固溶し、焼入れ性(hardenability)を向上させる効果を有する元素である。このような効果を得るためには、Mnの含有量が0.2%以上であることが好ましい。また、Mnの含有量が1.0%を超えても、効果が飽和し含有量に見合う効果が期待できなくなり、Mnの含有量を増加させることによる費用増加の分だけ経済的に不利となる。また、Mnの含有量が1.0%を超えると、ロール材が脆化する場合がある。このため、Mnの含有量は0.2~1.0%の範囲に限定することが好ましい。
Crは、Cと結合して主に共晶炭化物(eutectic carbide)を形成し、耐摩耗性を向上させるとともに、圧延時に鋼板とロール外層材表面との間の摩擦力を低減し、ロール表面の損傷を軽減させ、圧延を安定化させる作用を有する元素である。更に、本発明では、Crは、粒状炭化物(granular carbide)や基地中にも適度に固溶してロール外層材を強化する作用を有する。このような効果を得るために、Crの含有量を4.0%以上にすることが好ましい。一方、Crの含有量が7.5%を超えると、粗大な共晶炭化物が増加しすぎて、耐疲労性が低下する場合がある。このため、Crの含有量は4.0~7.5%の範囲に限定することが好ましい。
Moは、Cと結合して硬質な炭化物を形成し、耐摩耗性を向上させる元素である。また、Moは、硬質なMC型炭化物中に固溶して、炭化物を強化するとともに、共晶炭化物中にも固溶し、それら炭化物の破壊抵抗(fracture resistance)を増加させる。このような作用を介してMoは、ロール外層材の耐疲労性を向上させる。このような効果を得るために、Moの含有量を4.0%以上とすることが好ましい。また、Moの含有量が6.5%を超えると、Mo主体の硬脆な炭化物(hard and brittle carbide)が生成し、耐疲労性が低下する場合がある。このため、Moの含有量は4.0~6.5%の範囲に限定することが好ましい。
Vは、耐摩耗性と耐疲労性を兼備させるために、本発明において重要な元素である。Vは、極めて硬質な粒状炭化物(MC型炭化物)を形成し、耐摩耗性を向上させるとともに、粗大な共晶炭化物を分断、分散晶出(dispersedly crystallize)させることに有効に作用し、ロール外層材の耐疲労性を顕著に向上させる元素である。このような効果は、Vの含有量を5.3%以上にすることで顕著となる。また、7.0%を超えるVの含有は、MC型炭化物を粗大化させるとともに、MC型炭化物の遠心鋳造偏析(centrifugal casting segregation)を助長させる場合があり、この場合、熱間圧延用ロールの諸特性が不安定になる。このため、Vの含有量は5.3~7.0%の範囲に限定することが好ましい。
Nbは、粒状のMC型炭化物に固溶してMC型炭化物を強化し、Moと共存することにより破壊抵抗を増加させる作用を介し、耐疲労性を向上させる。また、Nbは、粗大な共晶炭化物の分断を促進させ、共晶炭化物の破壊を抑制する作用を有し、ロール外層材の耐疲労性を向上させる元素である。また、NbはMC型炭化物の遠心鋳造時の偏析を抑制する作用を有する。このような効果は、Nbの含有量が0.5%以上で顕著となる。また、3.0%を超えるNbの含有は、溶湯中でのMC型炭化物の成長を促進させ、遠心鋳造時の炭化物の偏析を助長する場合がある。このため、Nbの含有量は0.5~3.0%の範囲に限定することが好ましい。より好ましくは、0.5~2.0%である。
Al、REMは、いずれも粒状炭化物の生成を強く促進する作用があり、微細炭化物を増量する効果がある。このため、Alおよび、REMは、優れた耐疲労性をロール外層材に付与する。このような効果を得るためには、Al及びREMの少なくとも1種を合計で0.001%以上含有することが好ましい。Alの含有量が0.05%、あるいはREMの含有量が0.03%を超えても、効果が飽和し、さらにはガス欠陥(gas defect)を生じやすくなる。このため、Al:0.001~0.05%あるいはREM:0.001~0.03%の一種以上含有することが好ましい。
(ここで、Cr、Mo、V:各元素の含有量(質量%))
(Cr+Mo)量とV量の比が、1.5未満で(1)式を満足しない場合には、所望の優れた熱間転動疲労寿命を確保できなくなる場合がある。一方、(Cr+Mo)量とV量の比が2.4を超えると、粗大な共晶炭化物が増加しすぎ、熱間転動疲労寿命が著しく低下する場合がある。このため、(Cr+Mo)/Vを、1.5以上、2.4以下に限定することが好ましい。
得られたリング状試験材から図3に示す形状の疲労試験片(外径60mmφ、肉厚10mm、面取り有)を採取した。疲労試験片には、図3に示すようなノッチ(深さt:1.2mm、周方向長さL:0.8mm)を外周面の2箇所に、0.2mmφのワイヤを用いた放電加工(ワイヤカット)法で導入した。
Claims (4)
- 熱間圧延用複合ロールの外層に用いられる鋳鉄系ロール外層材であって、
円相当直径が3~30μmの微細炭化物を500~2500個/mm2含有し、かつ、円相当直径が50μm以上の粗大炭化物の存在が20個/mm2以下であることを特徴とするロール外層材。 - 質量%で、C:2.4~2.9%、Si:0.2~1.0%、Mn:0.2~1.0%、Cr:4.0~7.5%、Mo:4.0~6.5%、V:5.3~7.0%、Nb:0.5~3.0%、を含有し、かつCr、Mo、Vの含有量が下記(1)式を満足し、残部Feおよび不可避的不純物からなる組成を有することを特徴とする請求項1に記載のロール外層材。
記
1.5 ≦ (Cr+Mo)/V ≦ 2.4 ・・・(1)
ここで、Cr、Mo、V:各元素の含有量(質量%) - 前記組成に加えてさらに、質量%で、Al:0.001~0.05%あるいはREM:0.001~0.03%の一種以上を含有することを特徴とする請求項2に記載のロール外層材。
- 外層と内層が溶着一体化してなる熱間圧延用複合ロールであって、前記外層が請求項1ないし3に記載のロール外層材からなることを特徴とする熱間圧延用複合ロール。
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201480012268.5A CN105121043B (zh) | 2013-03-01 | 2014-02-25 | 轧辊外层材料及热轧用复合轧辊 |
US14/769,841 US9708695B2 (en) | 2013-03-01 | 2014-02-25 | Roll outer layer material, and composite roll for hot rolling |
KR1020157022876A KR101785182B1 (ko) | 2013-03-01 | 2014-02-25 | 롤 외층재 및 열간 압연용 복합 롤 |
ES14756297.9T ES2629413T3 (es) | 2013-03-01 | 2014-02-25 | Material de capa exterior de rodillo y rodillo de material compuesto para laminación en caliente |
CA2899293A CA2899293C (en) | 2013-03-01 | 2014-02-25 | Roll outer layer material, and composite roll for hot rolling |
EP14756297.9A EP2962776B1 (en) | 2013-03-01 | 2014-02-25 | Roll outer layer material, and composite roll for hot rolling |
BR112015019928-3A BR112015019928B1 (pt) | 2013-03-01 | 2014-02-25 | Material de camada externa de cilindro, e cilindro compósito para laminação a quente |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013-040298 | 2013-03-01 | ||
JP2013040298A JP5949596B2 (ja) | 2013-03-01 | 2013-03-01 | 熱間圧延用ロール外層材、および熱間圧延用複合ロール |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014132628A1 true WO2014132628A1 (ja) | 2014-09-04 |
Family
ID=51427905
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2014/000985 WO2014132628A1 (ja) | 2013-03-01 | 2014-02-25 | ロール外層材および熱間圧延用複合ロール |
Country Status (10)
Country | Link |
---|---|
US (1) | US9708695B2 (ja) |
EP (1) | EP2962776B1 (ja) |
JP (1) | JP5949596B2 (ja) |
KR (1) | KR101785182B1 (ja) |
CN (1) | CN105121043B (ja) |
BR (1) | BR112015019928B1 (ja) |
CA (1) | CA2899293C (ja) |
ES (1) | ES2629413T3 (ja) |
TW (1) | TWI577461B (ja) |
WO (1) | WO2014132628A1 (ja) |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5949596B2 (ja) | 2013-03-01 | 2016-07-06 | Jfeスチール株式会社 | 熱間圧延用ロール外層材、および熱間圧延用複合ロール |
JP6405894B2 (ja) * | 2014-10-30 | 2018-10-17 | 新日鐵住金株式会社 | 熱間圧延用ロール |
JP6621650B2 (ja) * | 2015-11-17 | 2019-12-18 | 株式会社フジコー | 熱延プロセス用ロールおよびその製造方法 |
CN105618485B (zh) * | 2016-01-29 | 2017-05-17 | 山东省四方技术开发有限公司 | 热轧无缝钢管定径机或减径机复合粒子强化轧辊及制备方法 |
CN105543641B (zh) * | 2016-01-29 | 2017-03-15 | 山东省四方技术开发有限公司 | 粒子强化热轧无缝钢管连轧机复合轧辊及其制备方法 |
CN109641250B (zh) * | 2016-09-07 | 2020-11-03 | 杰富意钢铁株式会社 | 热轧用辊外层材料及热轧用复合辊 |
BR112020026751A2 (pt) * | 2018-08-08 | 2021-03-30 | Hitachi Metals, Ltd. | Rolo compósito centrifugamente fundido para laminação e seu método de produção |
CN113166864B (zh) * | 2018-11-28 | 2022-09-23 | 杰富意钢铁株式会社 | 热轧用辊外层材料和热轧用复合辊 |
KR102190503B1 (ko) * | 2019-03-25 | 2020-12-11 | 현대제철 주식회사 | 워크롤의 성능 평가방법 |
CN113661019B (zh) * | 2019-04-03 | 2022-09-13 | 日铁轧辊株式会社 | 通过离心铸造法制造的轧制用复合辊及其制造方法 |
CN111922732A (zh) * | 2020-06-29 | 2020-11-13 | 河北偶园钛模具有限公司 | 一种无缝管穿孔机用复合导板的制造方法 |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03404A (ja) * | 1989-05-30 | 1991-01-07 | Nippon Steel Corp | 鋼板の熱間圧延用ロール |
JPH04365836A (ja) | 1990-10-01 | 1992-12-17 | Kawasaki Steel Corp | 圧延用ロール外層材 |
JPH051350A (ja) | 1990-11-21 | 1993-01-08 | Kawasaki Steel Corp | 圧延用ロール外層材 |
JPH05148510A (ja) * | 1991-04-22 | 1993-06-15 | Hitachi Metals Ltd | 耐摩耗複合ロール及びその製造方法 |
JPH05271875A (ja) * | 1992-03-30 | 1993-10-19 | Nippon Steel Corp | 耐摩耗性熱間圧延用ロール材質 |
JPH05339673A (ja) * | 1992-06-04 | 1993-12-21 | Kawasaki Steel Corp | ロール外層材及び複合ロール |
JPH0999306A (ja) * | 1995-10-06 | 1997-04-15 | Hitachi Metals Ltd | 熱間圧延用ロール |
JP2005105296A (ja) * | 2003-09-26 | 2005-04-21 | Jfe Steel Kk | 熱間圧延用ロール外層材および熱間圧延用複合ロール |
JP2007196257A (ja) * | 2006-01-26 | 2007-08-09 | Hitachi Metals Ltd | 圧延用ロール |
JP2009221573A (ja) | 2008-03-18 | 2009-10-01 | Jfe Steel Corp | 熱間圧延用遠心鋳造製複合ロール |
JP2010101752A (ja) | 2008-10-23 | 2010-05-06 | Jfe Steel Corp | 熱間圧延用ロールの評価方法 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2841276B2 (ja) | 1994-06-29 | 1998-12-24 | 川崎製鉄株式会社 | 熱間圧延用ロール外層材及び熱間圧延用ロールの製造方法 |
US5813962A (en) * | 1996-06-28 | 1998-09-29 | Kawasaki Steel Corporation | Forged roll for rolling a seamless steel pipe |
US8156651B2 (en) * | 2004-09-13 | 2012-04-17 | Hitachi Metals, Ltd. | Centrifugally cast external layer for rolling roll and method for manufacture thereof |
JP4569358B2 (ja) * | 2005-04-04 | 2010-10-27 | Jfeスチール株式会社 | 熱間圧延用鋳造ロール材および熱間圧延用ロール |
KR101281135B1 (ko) | 2005-12-28 | 2013-07-02 | 히타치 긴조쿠 가부시키가이샤 | 원심 주조 복합롤 |
CN101386961A (zh) | 2007-09-14 | 2009-03-18 | 日立金属株式会社 | 离心铸造制轧辊 |
JP5434276B2 (ja) * | 2009-05-29 | 2014-03-05 | Jfeスチール株式会社 | 熱間圧延用遠心鋳造製複合ロール |
CN102330014B (zh) | 2011-10-31 | 2013-03-06 | 驻马店市永诚耐磨材料有限公司 | 一种抗磨铸铁材料 |
EP2706128B1 (en) * | 2011-11-21 | 2016-02-03 | Hitachi Metals, Ltd. | Centrifugally cast composite rolling mill roll and manufacturing method therefor |
JP5949596B2 (ja) | 2013-03-01 | 2016-07-06 | Jfeスチール株式会社 | 熱間圧延用ロール外層材、および熱間圧延用複合ロール |
-
2013
- 2013-03-01 JP JP2013040298A patent/JP5949596B2/ja active Active
-
2014
- 2014-02-25 BR BR112015019928-3A patent/BR112015019928B1/pt active IP Right Grant
- 2014-02-25 CN CN201480012268.5A patent/CN105121043B/zh active Active
- 2014-02-25 EP EP14756297.9A patent/EP2962776B1/en active Active
- 2014-02-25 KR KR1020157022876A patent/KR101785182B1/ko active IP Right Grant
- 2014-02-25 WO PCT/JP2014/000985 patent/WO2014132628A1/ja active Application Filing
- 2014-02-25 ES ES14756297.9T patent/ES2629413T3/es active Active
- 2014-02-25 CA CA2899293A patent/CA2899293C/en active Active
- 2014-02-25 US US14/769,841 patent/US9708695B2/en active Active
- 2014-02-27 TW TW103106711A patent/TWI577461B/zh active
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03404A (ja) * | 1989-05-30 | 1991-01-07 | Nippon Steel Corp | 鋼板の熱間圧延用ロール |
JPH04365836A (ja) | 1990-10-01 | 1992-12-17 | Kawasaki Steel Corp | 圧延用ロール外層材 |
JPH051350A (ja) | 1990-11-21 | 1993-01-08 | Kawasaki Steel Corp | 圧延用ロール外層材 |
JPH05148510A (ja) * | 1991-04-22 | 1993-06-15 | Hitachi Metals Ltd | 耐摩耗複合ロール及びその製造方法 |
JPH05271875A (ja) * | 1992-03-30 | 1993-10-19 | Nippon Steel Corp | 耐摩耗性熱間圧延用ロール材質 |
JPH05339673A (ja) * | 1992-06-04 | 1993-12-21 | Kawasaki Steel Corp | ロール外層材及び複合ロール |
JPH0999306A (ja) * | 1995-10-06 | 1997-04-15 | Hitachi Metals Ltd | 熱間圧延用ロール |
JP2005105296A (ja) * | 2003-09-26 | 2005-04-21 | Jfe Steel Kk | 熱間圧延用ロール外層材および熱間圧延用複合ロール |
JP2007196257A (ja) * | 2006-01-26 | 2007-08-09 | Hitachi Metals Ltd | 圧延用ロール |
JP2009221573A (ja) | 2008-03-18 | 2009-10-01 | Jfe Steel Corp | 熱間圧延用遠心鋳造製複合ロール |
JP2010101752A (ja) | 2008-10-23 | 2010-05-06 | Jfe Steel Corp | 熱間圧延用ロールの評価方法 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2962776A4 |
Also Published As
Publication number | Publication date |
---|---|
US20150376748A1 (en) | 2015-12-31 |
EP2962776A1 (en) | 2016-01-06 |
CN105121043A (zh) | 2015-12-02 |
TW201446351A (zh) | 2014-12-16 |
CA2899293A1 (en) | 2014-09-04 |
CA2899293C (en) | 2017-10-24 |
CN105121043B (zh) | 2017-03-08 |
JP5949596B2 (ja) | 2016-07-06 |
BR112015019928A2 (pt) | 2017-07-18 |
EP2962776A4 (en) | 2016-04-13 |
EP2962776B1 (en) | 2017-04-19 |
ES2629413T3 (es) | 2017-08-09 |
JP2014168783A (ja) | 2014-09-18 |
KR20150110733A (ko) | 2015-10-02 |
TWI577461B (zh) | 2017-04-11 |
US9708695B2 (en) | 2017-07-18 |
KR101785182B1 (ko) | 2017-10-12 |
BR112015019928B1 (pt) | 2022-07-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2014132628A1 (ja) | ロール外層材および熱間圧延用複合ロール | |
JP5136138B2 (ja) | 熱間圧延用遠心鋳造製複合ロール | |
WO2013057914A1 (ja) | 耐疲労性に優れた熱間圧延用遠心鋳造製ロール外層材および熱間圧延用遠心鋳造製複合ロール | |
JP5862526B2 (ja) | 熱間圧延用ロール外層材および熱間圧延用複合ロール | |
JP5703718B2 (ja) | 熱間圧延用遠心鋳造製ロール外層材および複合ロール | |
JP5434276B2 (ja) | 熱間圧延用遠心鋳造製複合ロール | |
JP5516545B2 (ja) | 耐疲労性に優れた熱間圧延用遠心鋳造製ロール外層材および熱間圧延用遠心鋳造製複合ロール | |
JP6292362B1 (ja) | 熱間圧延用ロール外層材および熱間圧延用複合ロール | |
JP2006281301A (ja) | 圧延用複合ロール | |
JP5434249B2 (ja) | 熱間圧延用遠心鋳造製複合ロール | |
JP5447812B2 (ja) | 熱間圧延用遠心鋳造製複合ロール | |
JP5867143B2 (ja) | 耐疲労性に優れた熱間圧延用遠心鋳造製ロール外層材および熱間圧延用遠心鋳造製複合ロール、ならびにそれらの製造方法 | |
JP5327342B2 (ja) | 耐疲労性に優れた熱間圧延用遠心鋳造製ロール外層材および熱間圧延用遠心鋳造製複合ロール | |
JP2018161655A (ja) | 熱間圧延用ロール外層材および熱間圧延用複合ロール | |
JP5867144B2 (ja) | 耐疲労性に優れた熱間圧延用遠心鋳造製ロール外層材および熱間圧延用遠心鋳造製複合ロール、ならびにそれらの製造方法 | |
JPWO2020110660A1 (ja) | 熱間圧延用ロール外層材および熱間圧延用複合ロール | |
JP2005296955A (ja) | 熱間圧延用アダマイトロール |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 14756297 Country of ref document: EP Kind code of ref document: A1 |
|
REEP | Request for entry into the european phase |
Ref document number: 2014756297 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2014756297 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2899293 Country of ref document: CA |
|
ENP | Entry into the national phase |
Ref document number: 20157022876 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14769841 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
REG | Reference to national code |
Ref country code: BR Ref legal event code: B01A Ref document number: 112015019928 Country of ref document: BR |
|
ENP | Entry into the national phase |
Ref document number: 112015019928 Country of ref document: BR Kind code of ref document: A2 Effective date: 20150819 |