JPWO2017043360A1 - Clad plate and manufacturing method thereof - Google Patents

Abstract

Provided is a clad plate having high resistance against deformation during use due to frictional pressure and frictional heat even when used as a material for a sliding member used in a particularly severe sliding environment. A clad plate 1 having a first layer 2, a second layer 3, and a third layer 4 stacked in this order in the thickness direction. The first layer 2 and the third layer 4 are quench hardened carbon steel or martensitic stainless steel, and are made of the same material. The second layer 3 is made of an aluminum alloy. The yield strength of the aluminum alloy at 400 ° C. is more than 10 MPa. The yield strength of the aluminum alloy at room temperature after complete annealing is 1/10 or less of the yield strength of quench-hardened carbon steel or martensitic stainless steel. The difference in residual stress between the first layer 2 and the third layer 4 is within 150 MPa.

Description

  The present invention relates to a clad plate and a manufacturing method thereof.

  A metal plate used as a material for a sliding member of a mechanical part (for example, a rotor plate or a clutch plate of a reduction gear) has a high wear-resistant surface so that it does not cause damage due to friction during sliding. As required.

  This metal plate is required to efficiently dissipate heat generated by friction by being excellent in thermal conductivity. This metal plate is required to have high surface pressure and high resistance to deformation due to thermal cycle when the sliding environment such as pressure and thermal cycle is severe.

  Increasing the hardness of at least the metal material used for the surface is effective for obtaining a sliding member having a surface with excellent wear resistance. This hardness is desirably 350 Hv or more in terms of Vickers hardness as defined in JIS Z2244: 2009. A quench-hardened carbon steel plate or a quench-hardened martensitic stainless steel plate is known as a metal plate having excellent wear resistance.

  These metal plates made of a single material have low thermal conductivity. Since these metal plates cannot sufficiently dissipate heat generated during sliding, they are thermally deformed or damaged by seizure.

  A clad plate made by laminating and bonding a metal plate having excellent wear resistance and a metal plate having excellent thermal conductivity is effective for improving the thermal conductivity of the metal plate having excellent wear resistance. It is.

  The present inventor disclosed, in Patent Document 1, a clad plate having excellent wear resistance and thermal conductivity composed of three layers. The three layers are a metal layer having a Vickers hardness of 350 Hv or more on at least one surface, an aluminum or aluminum alloy layer, and an arbitrary metal layer.

JP 2005-21899 A

  As a result of the study by the present inventors, the clad plate disclosed in Patent Document 1 is used as a material for a sliding member used in a severe sliding environment, and the aluminum or aluminum alloy layer has a high surface pressure. It has been found that there is a risk of compression and deformation, and that warpage may occur due to thermal cycling. In particular, if the amount of warpage generated is large, the sliding member interferes with other members, making it impossible to use mechanical parts.

  An object of the present invention is a clad plate having a surface layer made of a high-hardness metal material having excellent wear resistance and an intermediate layer having excellent thermal conductivity, and particularly under a severe sliding environment, It is an object of the present invention to provide a clad plate that can prevent both an intermediate layer from being compressed and deformed by a high surface pressure and a warp from being caused by a thermal cycle, and a method for manufacturing the same.

  That is, an object of the present invention is to provide a high resistance to deformation caused by frictional pressure and frictional heat. It is to provide a manufacturing method thereof.

The inventor obtained the knowledge A to E listed below and completed the present invention.
(A) A clad plate composed of three layers of a first layer (surface layer), a second layer (intermediate layer), and a third layer (surface layer) is used as a material for a sliding member used in a particularly severe sliding environment. Used.

  (B) Quench-hardened carbon steel or quench-hardened martensitic stainless steel, and the same material is used as the first layer and the third layer.

  (C) An aluminum alloy is used as the second layer. The yield strength of this aluminum alloy at 400 ° C. is over 10 MPa. Furthermore, the proof stress of this aluminum alloy at room temperature after complete annealing is 1/10 or less of the proof strength of the quench-hardened carbon steel or quench-hardened martensitic stainless steel constituting the first and third layers.

  (D) The absolute value of the difference in residual stress between the first layer and the third layer is within 150 MPa. Thereby, generation | occurrence | production of the curvature (thermal deformation) in use as a sliding member is prevented substantially.

(E) The clad plate having the first layer, the second layer, and the third layer can substantially prevent deformation of the sliding member even when exposed to a high surface pressure or thermal cycle.
The present invention is listed below.

(1) A clad plate comprising a first layer, a second layer, and a third layer laminated in this order in the thickness direction,
The first layer and the third layer are quench-hardened carbon steel or quench-hardened martensitic stainless steel, and are made of the same material,
The second layer is made of an aluminum alloy,
The proof stress of the aluminum alloy at 400 ° C. is more than 10 MPa,
The yield strength of the aluminum alloy at room temperature after complete annealing is 1/10 or less of the yield strength of the quench-hardened carbon steel or quench-hardened martensitic stainless steel,
The clad plate, wherein an absolute value of a difference in residual stress between each of the first layer and the third layer is within 150 MPa.

  (2) The clad plate according to item 1, wherein the aluminum alloy is a 3000 series aluminum alloy or a 5000 series aluminum alloy specified in JIS H4000: 2014.

  (3) The clad plate according to 1 or 2, wherein the hardness of each of the first layer and the third layer is Vickers hardness of 350 Hv or more as defined in JIS Z2244: 2009.

(4) The clad plate according to 1 or 2, wherein a warpage amount measured by the following friction test is 1.5 mm or less.
Friction test: A clad plate was processed into a disk with a diameter of 100 mm, and a position 10 mm away from the outermost periphery of the disk in the radial direction was made of two materials of SUJ2 defined in JIS G4805: 2008 and a cross-sectional area of 1 cm ² . Rotate the disk at 100 rpm while applying a load of 100 N with a pin, and when the surface temperature of the disk reaches 300 ° C., increase the load to 1000 N and perform braking for 10 cycles. Place it flat on the board and measure the amount of warpage, which is the maximum value of the amount of the disc separated from the surface of the surface plate.

  (5) The clad plate according to 1 or 2, wherein a bonding strength between the first layer and the third layer and the second layer is 10 N / mm or more.

(6) From the same material as the first quench-hardened carbon steel plate or quench-hardened martensitic stainless steel plate, an aluminum alloy plate, and the first quench-hardened carbon steel plate or quench-hardened martensitic stainless steel plate The second quenching-hardened carbon steel plate or the quench-hardening martensitic stainless steel plate is heated to 250 to 430 ° C., and laminated in this order to form a laminate,
The laminate is joined and rolled at a rolling reduction of 10% or more, a first layer made of quench-hardened carbon steel or quench-hardened martensitic stainless steel, a second layer made of an aluminum alloy, and the first layer, A first rolling step as a clad band having a third layer made of the same material;
A first heat treatment step of performing a first heat treatment for holding the clad band at 300 to 500 ° C. for 3 minutes or more;
A second rolling step of rolling the clad band subjected to the first heat treatment at a rolling reduction of 2.0% or more and a breaking elongation value or less while applying a front tension and a rear tension of 10 kg / mm ² or more;
A method for manufacturing a clad plate, comprising: a second heat treatment step of performing a second heat treatment in which the clad band rolled while being applied with the front tension and the rear tension is held at 300 to 500 ° C. for 3 minutes or more.
However, the values of the front tension and the rear tension are obtained based on the cross-sectional areas of the first layer and the third layer in the cladding band.

(7) The method for manufacturing a clad plate according to item 6, wherein the front tension is 15 kg / mm ² or more.

  (8) The method for manufacturing a clad plate according to item 6 or 7, including a flattening step of flattening the clad band subjected to the second heat treatment with a leveler.

  The clad plate according to the present invention has high resistance to deformation during use due to frictional pressure and frictional heat. When the clad plate according to the present invention is used as a material for a sliding member that is used particularly in a severe sliding environment, the second layer is compressed and deformed by a high surface pressure, and warping is a thermal cycle. Can be substantially prevented.

  For this reason, the clad plate according to the present invention is suitably used as a material for a sliding member used in a particularly severe sliding environment.

FIG. 1 is an explanatory view showing the overall configuration of an example of a clad plate according to the present invention.

1. Clad plate 1 according to the present invention
(1) Overall Configuration FIG. 1 is an explanatory diagram showing an overall configuration of an example of a clad plate 1 according to the present invention.

  As shown in FIG. 1, the clad plate 1 includes a first layer (surface layer) 2, a second layer (intermediate layer) 3, and a third layer (surface layer) 4. The second layer 3 is joined to the first layer 2 through one of the two surfaces. The second layer 3 is joined to the third layer 4 through the other of the two surfaces.

  The clad plate 1 has a first layer 2 and a third layer 4 made of a hard metal having excellent wear resistance as surface layers. Furthermore, the clad plate 1 has a second layer 3 made of an aluminum alloy having excellent thermal conductivity as an intermediate layer.

  For example, a clad plate composed of two layers of high hardness metal and aluminum, or a clad plate composed of three layers having metals having different coefficients of thermal expansion in the first layer 2 and the third layer 4 is subject to thermal deformation due to the bimetal effect. Since it occurs during use as a moving member, deformation due to thermal cycling cannot be suppressed.

  For this reason, the clad plate 1 according to the present invention is a clad plate composed of three layers of a first layer 2, a second layer 3 and a third layer 4. The first layer 2 and the third layer 4 are both quench-hardened carbon steel or quench-hardened martensitic stainless steel, and are made of the same material. Further, the second layer 3 is made of an aluminum alloy.

  In the present invention, “the first layer 2 and the third layer 4 are made of the same material” means that the first layer 2 and the third layer 4 are both hardened and hardened by carbon steel, or are hardened by hardening. It is martensitic stainless steel, and means that the phase and strength as a metal structure are the same within the range of industrial production variation, and does not mean that the chemical composition is completely the same.

(2) First layer 2 and third layer 4
Both the first layer 2 and the third layer 4 are quench-hardened carbon steel or quench-hardened martensitic stainless steel (collectively referred to as “quenze hardened steel” in the following description), and are made of the same material. .

The reason why the hardened steel is used as the first layer 2 and the third layer 4 is as follows.
(A) Quenching hardened steel can exhibit excellent wear resistance, Vickers hardness of 350 Hv or more can be easily obtained, and

(B) The characteristic due to the temperature history, which is the cause of deformation in the operating temperature range of the clad plate 1 (room temperature to 400 ° C., and the range of 500 ° C. which is the highest temperature allowed only for a short time). A change is restrained comparatively small by heat-treating at 300-500 degreeC before use and age-hardening.

  The difference in residual stress between the first layer 2 and the third layer 4 is within 150 MPa, and is suppressed to a small value. Thereby, the clad plate 1 can substantially prevent warpage during use as a sliding member. This difference in residual stress is desirably within 100 MPa, and more desirably within 80 MPa.

The residual stress of each of the first layer 2 and the third layer 4 of the clad plate 1 is measured for the stress in the direction parallel to the rolling direction on the outer surface of each of the first layer 2 and the third layer 4, and an X-ray diffractometer is used. It is calculated from the gradient of the 2θ-sin ² ψ diagram obtained by the parallel tilt method measurement. The difference in residual stress between the first layer 2 and the third layer 4 is obtained by subtracting the residual stress at the outer surface of the third layer 4 from the residual stress at the outer surface of the first layer 2.

(3) Second layer 3
The second layer 3 is made of an aluminum alloy. The yield strength of this aluminum alloy at 400 ° C. is over 10 MPa. Furthermore, the proof stress of this aluminum alloy at room temperature after complete annealing is 1/10 or less of the proof strength of quench-hardened steel.

  Copper, aluminum, a copper alloy, or an aluminum alloy is considered as a metal having excellent thermal conductivity used for the second layer (intermediate layer) 3. An aluminum alloy capable of warm rolling joining in the air is desirable from the viewpoint of the productivity of the clad plate.

  When the proof stress of the second layer 3 is less than 10 MPa at 400 ° C. (the upper limit of the continuous use temperature range of the clad plate 1), The two layers 3 may be subjected to compression plastic deformation due to high frictional force and frictional heat generation, and the sliding member may be deformed. For this reason, the second layer 3 of the clad plate 1 is made of an aluminum alloy, not pure aluminum (1000 series) defined by JIS H4000: 2014.

The yield strength of the second layer 3 at 400 ° C. is desirably 12 MPa or more, and more desirably 15 MPa or more.
Furthermore, the proof stress of the aluminum alloy used as the second layer 3 as the intermediate layer is 1/10 or less of the proof strength of the hardened hardened steel used as the first layer 2 and the third layer 4. Thereby, even if the sliding member is heated by the thermal history during sliding and a difference in thermal expansion occurs between the first layer 2, the third layer 4 and the second layer 3, it is made of an aluminum alloy having a low yield strength. The second layer 3 is plastically deformed to release the stress and the warpage is reduced.

  The proof stress of the aluminum alloy is desirably 1 / 12.5 or less of the proof strength of the hardened and hardened steel used as the first layer 3 and the third layer 4.

  In particular, when the thicknesses of the first layer 2 and the third layer 4 are different from before the start of use, or because the first layer 2 and the third layer 4 are unevenly thinned due to wear during use, the first layer Even when the thicknesses of the second layer 3 and the third layer 4 are different, the proof stress of the aluminum alloy of the second layer 3 is sufficiently smaller than the proof strength of the hardened hardened steel of the first layer 2 and the third layer 4. The deformation of the sliding member is reduced.

  In order to satisfy the characteristics required for the second layer 3, it is desirable to use a 3000-series or 5000-series non-heat-treatable aluminum alloy defined by JIS H4000: 2014 for the second layer 3.

  The proof stress of heat treatment type (precipitation hardening type) aluminum alloys of 2000 series, 6000 series and 7000 series represented by duralumin is high. However, the strength of the heat-treatable aluminum alloy varies greatly within the operating temperature range (room temperature to 500 ° C.) of the clad plate 1. For this reason, it is not desirable to use the heat treatment type aluminum alloy for the second layer 3.

  The thickness of each of the first layer 2, the second layer 3, and the third layer 4 may be appropriately set in consideration of the performance required for the sliding member. The thicknesses of the first layer 2 and the third layer 4 are preferably the same in order to reduce warpage. For example, the thickness of each of the first layer 2 and the third layer 4 is 0.2 to 1.0 mm, and the thickness of the second layer is 0.5 to 1.0 mm.

2. Manufacturing method of clad plate 1 (1) Overall process The method of manufacturing the clad plate 1 is substantially the same as the method disclosed in Patent Document 1. The difference is that the second rolling is performed by increasing the forward tension on the clad band, and if necessary, flattening is performed by a leveler in the final step.

[Lamination process]
The material of the first layer 2 (hardened carbon steel having a Vickers hardness of 350 Hv or more or quench-hardened martensitic stainless steel plate, hereinafter collectively referred to as “quenching-hardened steel plate”) and the second layer 3 The material (aluminum alloy plate) and the material of the third layer 4 (quenched hardened steel plate made of the same material as the first layer 2) are individually heated to 250 to 430 ° C. and laminated in this order. The process of making the body,

[First rolling step]
The laminated body is joined and rolled (first rolling) at a rolling reduction of 10% or more, a first layer made of quench-hardened steel, a second layer made of an aluminum alloy, and a third layer made of the same material as the first layer. A clad band having

[First heat treatment step]
Performing a first heat treatment for holding the clad band at 300 to 500 ° C. for 3 minutes or more;
[Second rolling step]
Applying a first tension and a rear tension of 10 kg / mm ² or more to the clad band subjected to the first heat treatment and performing a second rolling at a rolling reduction of 2.0% or more and a breaking elongation value or less; and

[Second heat treatment step]
The clad plate 1 is manufactured through a step of performing a second heat treatment in which the clad band subjected to the second rolling is held at 300 to 500 ° C. for 3 minutes or more. Further if necessary

[Flatening process]
A step of flattening the clad band subjected to the second heat treatment with a leveler may be performed. Hereinafter, each process is demonstrated one by one.

(2) Lamination process and first rolling process First, a hardened and hardened steel plate as a material of the first layer 2, an aluminum alloy plate as a material of the second layer 3, and a first material composed of the same material as the first layer 2 The hardened and hardened steel sheet, which is the material of the three layers 4, is individually heated to 250 ° C. or higher and 430 ° C. or lower and laminated in this order to form a laminated body. Then, this laminated body is joined and rolled (first rolling) at a rolling reduction of 10% or more to form a clad band.

  When the heating temperature is less than 250 ° C., the chemical activity of the bonding interface cannot be sufficiently obtained. On the other hand, when the heating temperature is higher than 430 ° C., a thick oxide film is formed on the surface of the material of the first layer 2, the second layer 3, and the third layer 4, and bonding is inhibited. For this reason, sufficient bonding strength cannot be obtained in any case. Accordingly, the heating temperature is 250 to 430 ° C. The heating temperature is desirably 300 ° C. or higher, desirably 400 ° C. or lower.

  The first rolling is performed so that the material of the first layer 2, the material of the second layer 3, and the material of the third layer 4 are in a temporarily bonded state and the mutual diffusion proceeds by the first heat treatment after the first rolling. However, if the rolling reduction of the first rolling is less than 10%, the mutual diffusion does not proceed sufficiently at the joint interface even if the first heat treatment is performed.

  Therefore, the rolling reduction of the first rolling is 10% or more, desirably 20% or more. The upper limit of the rolling reduction of the first rolling is not limited. The rolling reduction of the first rolling is desirably 60% or less, desirably 50% or less, from the viewpoint of increasing the load on the rolling mill and difficulty in securing the product shape. The reduction ratio (%) is obtained as 100 × {(plate thickness of the laminate) − (plate thickness of the clad band)} / (plate thickness of the laminate).

  In the laminating step and the first rolling step, the laminated body in which the materials of the first layer 2, the second layer 3 and the third layer 4 are laminated is warm-rolled and joined in the air. Thus, the laminate is a clad band having a first layer made of quench-hardened steel, a second layer made of an aluminum alloy, and a third layer made of the same material as the first layer.

  The material (quenched hardened steel plate) of each of the first layer 2 and the third layer 4 constituting the clad plate 1 has a particularly high strength compared to the material of the second layer 3 (aluminum alloy plate). For this reason, only the material (aluminum alloy plate) of the second layer 3 expands during the joining rolling.

  A new surface necessary for clad bonding is hardly generated in each material (quenched hardened steel plate) of the first layer 2 and the third layer 4 constituting the clad plate 1. For this reason, the clad band which completed the 1st rolling does not have sufficient joint strength. The material of the first layer 2, the material of the second layer 3, and the material of the third layer 4 are in a temporarily joined state.

(3) 1st heat treatment process and 2nd rolling process The 1st heat processing hold | maintained at 300 degreeC or more and 500 degrees C or less for 3 minutes or more is performed to the clad belt obtained through the 1st rolling process. Further, the second rolling is performed on the clad band subjected to the first heat treatment. In the second rolling, the rolling reduction: 2.0% or more and the breaking elongation value or less, the front tension (tension in the rolling direction on the exit side of the rolling mill) and the rear tension (in the direction opposite to the rolling direction on the entrance side of the rolling mill) (Tension): 10 kg / mm ² or more. However, the values of the front tension and the rear tension are obtained based on the cross-sectional areas of the first layer and the third layer of the clad band.

  The first heat treatment is performed to advance interdiffusion at the bonding interface. High joint strength can be obtained by performing the second rolling and second heat treatment described later after the first heat treatment.

  However, when the temperature of the first heat treatment is less than 300 ° C., mutual diffusion does not proceed at the bonding interface. On the other hand, when the temperature of the first heat treatment exceeds 500 ° C., a brittle intermetallic compound is generated at the bonding interface. For this reason, in any case, finally sufficient bonding strength cannot be obtained. The temperature of the first heat treatment is desirably 320 ° C. or higher, desirably 400 ° C. or lower.

  Further, the interdiffusion at the bonding interface proceeds even by a short heat treatment. A heat treatment time of 3 minutes or more, preferably 10 minutes or more is effective for interdiffusing uniformly across the bonding interface. Therefore, 1st heat processing is performed by hold | maintaining at 300-500 degreeC for 3 minutes or more. The time for the first heat treatment is desirably 2 hours or less from the viewpoint of manufacturing cost.

  As described above, the clad band before the second rolling is in a state in which interdiffusion at the bonding interface has progressed by the first heat treatment. For this reason, the material of each of the first layer 2 and the third layer 4 (quenched hardened steel plate) and the material of the second layer 3 (aluminum alloy plate) are bonded with a certain degree of bonding strength (for example, 3 N / mm or more). The The material of each of the first layer 2, the second layer 3, and the third layer 4 is stretched at substantially the same reduction rate by performing the second rolling on the clad band in this state. Thereby, the new surface in the surface of the material of each of the first layer 2 and the third layer 4 is efficiently generated.

  The individual reduction ratios of the first layer 2, the second layer 3, and the third layer 4 are almost the same as the total reduction ratio. For this reason, a new surface is generated on the surface of the material of each of the first layer 2 and the third layer 4 at the same ratio as the total rolling reduction, and joining proceeds.

  However, if the rolling reduction of the second rolling is less than 2.0%, the bonding strength of the clad plate 1 is less than 10 N / mm even if the second heat treatment is performed after the second rolling. For this reason, the rolling reduction of 2nd rolling is 2.0% or more, Preferably it is 3.0% or more.

  On the other hand, when the second rolling is performed at a reduction rate exceeding the fracture elongation value of the clad band after the first heat treatment, intermittent cracks occur in the first layer 2 and the third layer 4, and the joint interface of the clad band peels off. To do. For this reason, the rolling reduction of the second rolling is not more than the breaking elongation value of the clad band after the first heat treatment.

  The rolling reduction (%) of the second rolling is 100 × {(the thickness of the clad band before the second rolling) − (the thickness of the clad band after the second rolling)} / (the clad before the second rolling) It is calculated as the thickness of the strip).

  Thus, the clad band has a bonding strength that can withstand the second rolling performed subsequently by performing the first heat treatment. And the raw material (hardening hardening steel plate) of each of the 1st layer 2 and the 3rd layer 4 is extended by performing the 2nd rolling to a clad belt. As a result, a new surface is generated at the bonding interface.

  The reason why the second rolling is performed by increasing the forward tension on the clad band is to uniformize the processing strain applied to the materials of the first layer 2 and the third layer 4 by the second rolling, and thereby the surface of the clad plate 1. This is because the absolute value of the difference in residual stress between the first layer 2 and the third layer 4 forming the back surface is reduced.

  The reduction force required for deformation of the clad band directly under the rolling roll is reduced by the increase of the rear tension, and the plate thickness is reduced by a smaller reduction force. On the other hand, the difference in residual stress inherent in each of the first layer and the third layer of the rolled clad band is reduced by an increase in the front tension, and the surface layer of each of the first layer 2 and the third layer 4 of the clad plate 1 The difference in residual stress at is as small as 150 MPa.

  Generally, in cold rolling of a metal plate, the rear tension is increased in order to reduce the rolling load. On the other hand, in this invention, the processing strain provided to each of the 1st layer 2 and the 3rd layer 4 is equalize | homogenized by raising front tension and performing 2nd rolling.

The values of the front tension and the rear tension are both determined based on the cross-sectional areas of the first layer and the third layer in the clad band and are 10 kg / mm ² or more. The forward tension is desirably 15 kg / mm ² or more. The forward tension is desirably 35 kg / mm ² or less because there is a risk of causing warping due to shrinkage deformation in the plate width direction if it is excessively increased.

(4) Second heat treatment step and flatness correction step The clad plate 1 is manufactured by performing a second heat treatment that is held at 300 to 500 ° C. for 3 minutes or more. The purpose of the second heat treatment is to ensure the bonding strength necessary for the clad plate 1 and to homogenize each of the first layer 2, the second layer 3 and the third layer 4 prior to use as a sliding member. By doing so, the strength of each of the first layer 2, the second layer 3, and the third layer 4 is not changed by the thermal cycle in use.

  The joint strength of the clad band increases rapidly by performing the second rolling and the second heat treatment. A new surface is generated at the bonding interface of the respective materials of the first layer 2 and the third layer 4 that have been subjected to the second rolling. However, interdiffusion does not proceed to this bonding interface. For this reason, the joining strength of the clad band after the second rolling is small. By performing the second heat treatment on the clad band, mutual diffusion proceeds to the bonding interface and the bonding strength increases.

  However, when the temperature of the second heat treatment is less than 300 ° C., mutual diffusion does not proceed at the bonding interface. On the other hand, when the temperature of the second heat treatment exceeds 500 ° C., a brittle intermetallic compound is generated at the bonding interface. Therefore, in any case, sufficient bonding strength cannot be obtained. The temperature of the second heat treatment is desirably 300 ° C. or higher, desirably 400 ° C. or lower.

  Here, a heat treatment time of 3 minutes or more is effective for obtaining uniform interdiffusion over the entire bonding interface. Therefore, the second heat treatment is performed by holding at 300 to 500 ° C. for 3 minutes or longer, desirably 10 minutes or longer. From the viewpoint of manufacturing cost, it is desirable that the time for the second heat treatment is 2 hours or less.

  In addition, the second heat treatment pre-generates age hardening that proceeds at 300 to 500 ° C. in martensitic stainless steel, and pre-softens heat treatment that proceeds at 300 to 500 ° C. in aluminum alloy. Thereby, the change of the characteristic by the heat cycle at the time of actual use of the clad board 1 is prevented.

  After performing the second heat treatment, it is desirable to perform leveling with a leveler as necessary. Thereby, the distortion of the balance of the internal stress which arises by the change of the said characteristic is homogenized.

  In this way, the clad plate 1 having the first layer 2 and the third layer 4 which are surface layers excellent in wear resistance and the second layer 3 which is an intermediate layer excellent in thermal conductivity is manufactured.

  The clad plate 1 is that the second layer 3 made of an aluminum alloy is compressed and deformed due to a high surface pressure particularly when used under a severe sliding environment, and warpage occurs due to a thermal cycle. Can be prevented.

  As shown in Table 1, the clad plate 1 shown in FIG. 1 was prepared and obtained by variously changing the composition and manufacturing conditions of the first layer 2, the second layer 3 and the third layer 4 respectively. The Vickers hardness and bonding strength of the first layer 2 of the clad plate 1 and the residual stress difference between the first layer 2 and the third layer 4 were measured. The residual stress difference was determined by the method described above. Further, the front tension and the rear tension of the second rolling were obtained by conversion from the power value of the reel motor.

  Moreover, the said friction test was done to the clad board 1 and the said curvature amount was measured. The case where the amount of warpage exceeded 1.5 mm was determined as defective.

  The test conditions and results are summarized in Table 1. Numbers 1 to 5 and 12 in Table 1 are examples of the present invention that satisfy all the rules of the present invention, and numbers 6 to 11 and 13 to 15 are comparative examples that do not satisfy the rules of the present invention.

  As shown in Table 1, in all of the inventive examples of numbers 1 to 5 and 12, the warpage amount is suppressed to a target value of 1.5 mm or less. In addition, although the example of this invention of the number 12 did not perform the flat correction by a leveler, although the amount of curvature was a little large with 1.5 mm, it was a pass level.

  On the other hand, in the comparative example of No. 6, since the Vickers hardness of the first layer is 320 Hv and does not reach the range of the present invention, the surface of the disk (the first layer 2 and the third layer 4) is worn by the friction test, Damaged at 7th cycle.

  In the comparative example of No. 7, since the first layer 2 and the third layer 4 are made of different materials, the warpage amount was 3.5 mm.

  In the comparative example of No. 8, since the heating temperature of the second layer 3 and the third layer 4 did not reach the range of the present invention, the bonding strength was low, and peeling occurred in the third cycle of the friction test, resulting in damage.

  The comparative example of No. 9 was not joined because the rolling reduction of the first rolling did not reach the range of the present invention, and the subsequent experiment was stopped.

  In the comparative example of No. 10, since the forward tension in the second rolling does not reach the range of the present invention, the processing strain applied to the first layer 2 and the third layer 4 is not uniform. The absolute value of the difference in residual stress between the three layers 4 exceeded the upper limit of the range of the present invention, and the amount of warpage was 1.7 mm.

  In the comparative example of No. 11, since the temperature of the second heat treatment does not reach the range of the present invention, the material characteristics of the first layer 2, the second layer 3 and the third layer 4 are not uniformized, and the warpage amount is 1. 9 mm.

  In Comparative Examples Nos. 13 and 15, since the proof stress at 400 ° C. of the aluminum alloy used as the second layer 3 did not reach the range of the present invention, the warpage amounts were 2.7 mm and 3.3 mm, respectively.

  Further, in Comparative Examples Nos. 14 and 15, since the yield strength of the aluminum alloy used as the second layer 3 at room temperature exceeded the range of the present invention, the warpage amounts were 2.1 mm and 3.3 mm, respectively.

DESCRIPTION OF SYMBOLS 1 Clad board 2 1st layer 3 2nd layer 4 3rd layer concerning this invention

Claims (8)

A clad plate comprising a first layer, a second layer, and a third layer laminated in this order in the thickness direction,
The first layer and the third layer are quench-hardened carbon steel or quench-hardened martensitic stainless steel, and are made of the same material,
The second layer is made of an aluminum alloy,
The proof stress of the aluminum alloy at 400 ° C. is more than 10 MPa,
The yield strength of the aluminum alloy at room temperature after complete annealing is 1/10 or less of the yield strength of the quench-hardened carbon steel or quench-hardened martensitic stainless steel,
The clad plate, wherein the difference in residual stress between the first layer and the third layer is within 150 MPa.   2. The clad plate according to claim 1, wherein the aluminum alloy is a 3000 series aluminum alloy or a 5000 series aluminum alloy defined in JIS H4000: 2014.   3. The clad plate according to claim 1, wherein the first layer and the third layer both have a Vickers hardness of 350 Hv or more as defined in JIS Z2244: 2009. The clad plate according to claim 1 or 2, wherein the amount of warpage measured by the following friction test is 1.5 mm or less.
Friction test: A clad plate was processed into a disk with a diameter of 100 mm, and a position 10 mm away from the outermost periphery of the disk in the radial direction was made of two materials of SUJ2 defined in JIS G4805: 2008 and a cross-sectional area of 1 cm ² . Rotate the disk at 100 rpm while applying a load of 100 N with a pin, and when the surface temperature of the disk reaches 300 ° C., increase the load to 1000 N and perform braking for 10 cycles. Place it flat on the board and measure the amount of warpage, which is the maximum value of the amount of the disc separated from the surface of the surface plate.   The clad plate according to claim 1 or 2, wherein a bonding strength between the first layer and the third layer and the second layer is 10 N / mm or more. The first quench-hardened carbon steel plate or the quench-hardened martensitic stainless steel plate, the aluminum alloy plate, and the same material as the first quench-hardened carbon steel plate or the quench-hardened martensitic stainless steel plate. A second quenching and hardening carbon steel plate or a quench hardening martensitic stainless steel plate is heated to 250 to 430 ° C. and laminated in this order to form a laminate,
The laminate is joined and rolled at a rolling reduction of 10% or more, a first layer made of quench-hardened carbon steel or quench-hardened martensitic stainless steel, a second layer made of an aluminum alloy, and the first layer, A first rolling step as a clad band having a third layer made of the same material;
A first heat treatment step of performing a first heat treatment for holding the clad band at 300 to 500 ° C. for 3 minutes or more;
A second rolling step of rolling the clad band subjected to the first heat treatment at a rolling reduction of 2.0% or more and a breaking elongation value or less while applying a front tension and a rear tension of 10 kg / mm ² or more;
A method for manufacturing a clad plate, comprising: a second heat treatment step of performing a second heat treatment in which the clad band rolled while being applied with the front tension and the rear tension is held at 300 to 500 ° C. for 3 minutes or more.
However, the values of the front tension and the rear tension are obtained based on the cross-sectional areas of the first layer and the third layer in the cladding band. The method for manufacturing a clad plate according to claim 6, wherein the front tension is 15 kg / mm ² or more.   The method for manufacturing a clad plate according to claim 6, further comprising a flattening step of flattening the clad band subjected to the second heat treatment with a leveler.

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