A method for preparing a high-chromium cast iron and stainless steel layered composite plate

Abstract

The present invention provides a preparation method of a layered composite plate of high-chromium cast iron and stainless steel, which belongs to the field of material processing technology. The present invention rolls the stainless steel plate into a single-sided corrugated plate of different thicknesses as the upper and lower substrates, and casts high-chromium cast iron between the corrugated interfaces of the upper and lower substrates to obtain a composite plate blank. The presence of the corrugation can improve the bonding strength between the stainless steel layer and the high-chromium cast iron layer; the composite plate blank is symmetrically assembled into a rolled plate blank and then hot-rolled. On the one hand, this can ensure that the rolled plate shape is straight, and on the other hand, after hot rolling and heat preservation, it is separated to obtain multiple layered composite plates, thereby improving production efficiency; the present invention utilizes hot rolling and heat preservation to complete metallurgical composite of the stainless steel substrate and the high-chromium cast iron, and reduce stress damage to the brittle high-chromium cast iron; the method provided by the present invention can improve the bonding strength between the layers of the layered composite plate, thereby achieving the purpose of improving its impact toughness without changing the wear resistance of the high-chromium cast iron.

Description

Technical Field

[0001] The invention relates to the technical field of material processing, and in particular to a method for preparing a high-chromium cast iron and stainless steel layered composite plate. Background Art

[0002] Although high-chromium cast iron has good hardness and wear resistance, its poor impact toughness limits its application. Improving its toughness without changing its hardness and wear resistance is a technical challenge that needs to be urgently addressed in high-chromium cast iron applications. Research has shown that composite plates made by laminating high-chromium cast iron with steel with good impact toughness can overcome the poor toughness of high-chromium cast iron by absorbing the excellent ductility and weldability of steel, while maintaining the hardness and wear resistance of high-chromium cast iron. This provides a possibility for improving the toughness of high-chromium cast iron without changing its hardness and wear resistance.

[0003] At present, the preparation method of high chromium cast iron / steel layered composite plate mainly includes solid-solid composite casting, solid-liquid composite casting and liquid-liquid centrifugal composite casting. However, there are many deficiencies in these preparation methods. For example, although the commonly used rolling composite method can roll brittle materials that are difficult to deform in the solid state, each layer of metal can also obtain metallurgical bonding, but brittle metal compounds are easily produced at the interface, and the rolling force can produce large stress damage to the brittle high chromium cast iron, easily produce defects such as cracks, and then cause the direct bonding strength of each layer of metal sheet to be weak. Therefore, it is urgent to provide a method for improving the bonding strength between high chromium cast iron and stainless steel layered composite plate. Summary of the Invention

[0004] The object of the present invention is to provide a method for preparing high chromium cast iron and stainless steel layered composite plates, which can improve the bonding strength between the layered composite plates.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a high-chromium cast iron and stainless steel layered composite plate, comprising the following steps:

[0007] (1) rolling a stainless steel plate into a single-sided corrugated plate of different thicknesses, which are used as an upper substrate and a lower substrate respectively; the thickness of the upper substrate is 10% to 90% of the thickness of the lower substrate;

[0008] (2) placing the corrugated surfaces of the upper substrate and the lower substrate obtained in step (1) opposite to each other and separated, and then casting high chromium cast iron between the upper substrate and the lower substrate to obtain a composite slab;

[0009] (3) assembling a plurality of composite slabs obtained in step (2) into a rolled slab, and then sequentially hot rolling, heat preservation, cooling and separation to obtain a high-chromium cast iron and stainless steel layered composite plate; the assembling comprises: stacking a plurality of composite slabs in a mirror-symmetrical manner, and coating an isolation agent between the composite slabs.

[0010] Preferably, the material of the stainless steel plate in step (1) includes 316 stainless steel, 321 stainless steel or 430 stainless steel.

[0011] Preferably, the corrugated cross-section of the single-sided corrugated plate in step (1) is arc-shaped, elliptical, sinusoidal, triangular, trapezoidal or rectangular.

[0012] Preferably, the corrugation height d in step (1) is 20% to 50% of the thickness of the corresponding substrate.

[0013] Preferably, the corrugation height d and the corrugation width t of the single-face corrugated plate satisfy t=(1-5)d.

[0014] Preferably, the high chromium cast iron in step (2) includes KmTBCr12, KmTBCr15Mo or KmTBCr20Mo.

[0015] Preferably, the step (2) further comprises: preheating the upper substrate and the lower substrate at 400-500° C. before casting.

[0016] Preferably, the end point temperature of hot rolling in step (3) is not lower than 1100°C.

[0017] Preferably, the reduction in each hot rolling pass in step (3) is 10% to 30%.

[0018] Preferably, the insulation temperature in step (3) is 600-800° C., and the insulation time is 20-60 minutes.

[0019] The present invention provides a preparation method of a high-chromium cast iron and stainless steel layered composite plate, comprising the following steps: rolling a stainless steel plate into a single-sided corrugated plate of different thicknesses, serving as an upper substrate and a lower substrate respectively; the thickness of the upper substrate is 10% to 90% of the thickness of the lower substrate; placing the corrugated surfaces of the upper and lower substrates opposite to each other and separated, and then casting high-chromium cast iron between the upper and lower substrates to obtain a composite slab; assembling multiple composite slabs into a rolled slab, and then sequentially hot-rolling, heat-insulating, cooling and separating to obtain a high-chromium cast iron and stainless steel layered composite plate; the assembly comprises: stacking the multiple composite slabs in a mirror-symmetrical manner, and coating an isolation agent between the composite slabs. The present invention rolls stainless steel plates into single-sided corrugated plates of different thicknesses, and casts high chromium cast iron between the corrugated interfaces of the upper and lower substrates to obtain composite slabs. The presence of the corrugations can improve the bonding strength between the stainless steel layer and the high chromium cast iron layer; the composite slabs are assembled into rolled slabs in a mirror-symmetrical manner and then hot-rolled. This, on the one hand, can make the composite slabs evenly stressed during hot rolling, ensuring the straightness of the rolled plate shape; on the other hand, by coating an isolation agent between the composite slabs, the composite slabs can be separated after hot rolling and heat preservation, so that multiple layered composite plates can be obtained, thereby improving production efficiency. Efficiency; The present invention utilizes hot rolling and heat preservation to complete metallurgical composite of stainless steel substrate and high-chromium cast iron, and reduces stress damage to brittle high-chromium cast iron, thereby improving the bonding strength between layered composite plates; The method provided by the present invention can improve the bonding strength between the layers of the layered composite plate. The thinner stainless steel layer in the prepared layered composite plate is first used as the working surface. After this surface is worn, the high-chromium cast iron layer with excellent wear resistance is exposed, further exerting its wear-resistant effect, thereby achieving the purpose of improving its impact toughness without changing the wear resistance of the high-chromium cast iron. The results of the embodiment show that the bonding strength of the layered composite plate prepared by the present invention is as high as 532.5Mpa. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of an upper substrate and a lower substrate prepared in Example 1 of the present invention;

[0021] Figure 2 This is a schematic structural diagram of a composite slab prepared in Example 1 of the present invention;

[0022] Figure 3 This is a schematic structural diagram of a rolled slab prepared in Example 1 of the present invention;

[0023] Figure 4 This is a schematic structural diagram of the high chromium cast iron and stainless steel layered composite plate prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0024] The present invention provides a method for preparing a high-chromium cast iron and stainless steel layered composite plate, comprising the following steps:

[0025] (1) rolling a stainless steel plate into a single-sided corrugated plate of different thicknesses, which are used as an upper substrate and a lower substrate respectively; the thickness of the upper substrate is 10% to 90% of the thickness of the lower substrate;

[0026] (2) placing the corrugated surfaces of the upper substrate and the lower substrate obtained in step (1) opposite to each other and separated, and then casting high chromium cast iron between the upper substrate and the lower substrate to obtain a composite slab;

[0027] (3) assembling a plurality of composite slabs obtained in step (2) into a rolled slab, and then sequentially hot rolling, heat preservation, cooling and separation to obtain a high-chromium cast iron and stainless steel layered composite plate; the assembling comprises: stacking a plurality of composite slabs in a mirror-symmetrical manner, and coating an isolation agent between the composite slabs.

[0028] The present invention rolls stainless steel plates into single-sided corrugated plates of different thicknesses, which serve as upper and lower substrates respectively. In the present invention, the thickness of the upper substrate is 10% to 90% of the thickness of the lower substrate, preferably 20% to 80%. In the present invention, the thickness of the upper and lower substrates within the above range can meet the requirements for wear resistance and toughness of the layered composite plate, thereby making the composite plate have excellent wear resistance and toughness. The present invention does not specifically limit the thickness of the upper and lower substrates, and can be selected according to the required product specifications and rolling mill parameters. In the present invention, the thickness of the upper substrate is preferably 5 mm, and the thickness of the lower substrate is preferably 10 mm. The present invention selects the thickness of the above substrates based on the thickness of the product to be prepared.

[0029] In the present invention, the material of the stainless steel plate preferably includes 316 stainless steel, 321 stainless steel or 430 stainless steel. In the present invention, when the stainless steel plate adopts the above materials, it has better impact toughness.

[0030] In the present invention, the corrugated cross section of the single-sided corrugated plate is preferably arc-shaped, elliptical, sinusoidal, triangular, trapezoidal or rectangular. In the present invention, the single-sided corrugated plate can improve the bonding strength between the stainless steel layer and the high chromium cast iron layer.

[0031] In the present invention, the corrugation height d is preferably 20% to 50% of the corresponding substrate thickness; the corrugation height d and the corrugation width t of the single-sided corrugated plate preferably satisfy t=(1 to 5)d. ​​The present invention does not specifically limit the specific values ​​of t and d, and they can be adjusted according to the thickness of the substrate, as long as they are within the above range. In the present invention, when the upper substrate used is 5mm, the d is preferably 1 to 2.5mm, more preferably 1.5 to 2.5mm; the t is preferably 4 to 10mm, more preferably 6 to 10mm; when the upper substrate used is 10mm, the d is preferably 2 to 5mm, more preferably 3 to 5mm; the t is preferably 8 to 20mm, more preferably 12 to 20mm. In the present invention, if the corrugation height is too low, it will not be conducive to improving the bonding strength between layers, and if the corrugation height is too high, the thickness of the wear-resistant layer will be reduced, thereby reducing the wear resistance.

[0032] The present invention is not particularly limited to the rolling method. A rolling method well known to those skilled in the art can be used to produce a single-sided corrugated stainless steel sheet, with the corrugation height and corrugation width of the single-sided corrugated sheet falling within the desired range. In the present invention, the rolling method is preferably: Based on product specifications, the stainless steel sheet is rolled into the single-sided corrugated sheet on a flat rolling mill with a corrugating roller as the upper roll and a flat roller as the lower roll.

[0033] After obtaining the upper substrate and the lower substrate, the present invention places the corrugated surfaces of the upper substrate and the lower substrate opposite and separately, and then casts high chromium cast iron between the upper substrate and the lower substrate to obtain a composite slab.

[0034] In the present invention, the corrugated surfaces of the upper and lower substrates are preferably polished and cleaned separately before placement. The present invention does not specifically limit the polishing and cleaning method; polishing and cleaning methods familiar to those skilled in the art can be employed. In the present invention, the polishing and cleaning can remove oxide layers and contaminants, protecting the surfaces to be bonded from contamination.

[0035] In the present invention, the upper and lower substrates are preferably placed in a vacuum casting chamber. In the present invention, the distance between the highest point of the corrugated surface of the upper substrate and the lowest point of the corrugated surface of the lower substrate is E, and the range of E is preferably greater than or equal to h and less than or equal to H. In the present invention, when E is within the above range, it can ensure that a high-chromium cast iron layer can be formed after the high-chromium cast iron melt is cast between the two substrates, and it is more conducive to improving the wear resistance and toughness of the layered composite plate.

[0036] In the present invention, the step of pre-casting preferably further includes preheating the upper and lower substrates at 400-500°C. Preheating the upper and lower substrates ensures that the stainless steel is fully preheated without annealing, thereby preventing cracks caused by excessive residual stress at the bimetallic interface due to a large temperature difference between the two materials during casting of high-chromium cast iron melt.

[0037] In the present invention, the casting is preferably vacuum casting. In the present invention, the vacuum degree of the vacuum casting is preferably 0.001 to 0.003 Pa, more preferably 0.002 to 0.003 Pa. In the present invention, when the vacuum degree of the vacuum casting is within the above range, it is more conducive to controlling the purity and composition stability of the casting.

[0038] The present invention does not particularly limit the casting method; any casting method known to those skilled in the art may be employed. In the present invention, the casting temperature is preferably 1400-1500°C, more preferably 1450-1500°C. In the present invention, high chromium cast iron has a melting point of 1200°C and a furnace tapping temperature of 1500°C. A casting temperature within this range is more conducive to controlling the quality of the high chromium cast iron layer.

[0039] In the present invention, the high chromium cast iron preferably includes KmTBCr12, KmTBCr15Mo or KmTBCr20Mo. In the present invention, the stainless steel plate is made of 316 stainless steel, 321 stainless steel or 430 stainless steel. When the high chromium cast iron is of the above types, it has similar deformation resistance to stainless steel, which is more conducive to obtaining a high-quality layered composite plate.

[0040] In the present invention, the cooling method of the casting is preferably natural cooling at room temperature. In the present invention, the cooling can form a preliminary metallurgical bond between the stainless steel and the high chromium cast iron.

[0041] After obtaining the composite slab, the present invention assembles multiple composite slabs into a rolled slab, and then sequentially performs hot rolling, heat preservation, cooling and separation to obtain a high chromium cast iron and stainless steel layered composite plate.

[0042] In the present invention, the number of the composite slabs is preferably 2, 4 or 6, more preferably 2. In the present invention, when the number of the composite slabs is within the above range, it is more conducive to controlling the rolling parameters.

[0043] In the present invention, the assembling comprises: stacking a plurality of composite slabs in a mirror-symmetrical manner, and coating a release agent between the composite slabs.

[0044] The present invention does not specifically limit the type and amount of the release agent; those familiar to those skilled in the art can be used. In the present invention, the release agent enables the natural separation of different composite slabs after hot rolling and heat preservation. In the present invention, the release agent is preferably a viscous mixture of Al2O3 and putty powder solution; the release agent coating thickness is preferably 1.5 to 2.0 mm.

[0045] The present invention preferably spot welds the four sides of each composite slab. The present invention does not specifically limit the method for spot welding; any spot welding method familiar to those skilled in the art can be employed. In the present invention, the spot welding prevents the different composite slabs from shifting relative to each other during hot rolling and holding. This ensures more uniform stress distribution across the rolled slabs, preventing warping of the composite slab.

[0046] In the present invention, the hot-rolled slab is preferably heated to a starting rolling temperature before hot rolling. In the present invention, the starting rolling temperature is preferably 1150-1200°C, more preferably 1150-1180°C. In the present invention, when the starting rolling temperature is within the above range, it is more advantageous to control the hot rolling temperature. In the present invention, the heating is preferably performed in a heating furnace.

[0047] In the present invention, the endpoint temperature of the hot rolling is preferably not less than 1100° C., more preferably 1100° C. In the present invention, 1100° C. is the plastic deformation temperature of high chromium cast iron. When the endpoint temperature of the hot rolling is within the above range, both high chromium cast iron and stainless steel have good plastic deformation capabilities within this temperature range.

[0048] The present invention has no particular limitation on the hot rolling device, and any hot rolling device well known to those skilled in the art can be used. In the present invention, the hot rolling device is preferably a flat rolling mill.

[0049] In the present invention, the hot rolling is preferably a multi-pass hot rolling; the reduction in each pass of the hot rolling is preferably 10% to 30%, more preferably 15% to 25%. The present invention does not specifically limit the total deformation of the hot rolling, which can be adjusted as needed. The total deformation is preferably 30 to 60%. The present invention does not specifically limit the number of hot rolling passes, which can be adjusted according to the required thickness. By controlling the deformation in each hot rolling pass within the above range, the present invention can ensure that the rolled slab is gradually deformed, avoid stress damage to the brittle high-chromium cast iron, and refine its grains, which is more conducive to further improving the bonding strength between the layered composite plates.

[0050] The present invention has no special limitation on the rolling speed, which can be adjusted according to actual conditions.

[0051] In the present invention, the holding temperature is preferably 600-800°C, more preferably 650-750°C; the holding time is preferably 20-60 minutes, more preferably 30-60 minutes. In the present invention, when the holding temperature and time are within the above ranges, diffusion heat treatment can be performed, achieving high-quality bimetallic cladding while uniformly deforming the hard and brittle high-chromium cast iron material, improving the bimetallic bonding strength of the composite plate product, and preventing crack defects in the high-chromium cast iron layer.

[0052] The present invention has no particular limitation on the cooling method, and a cooling method well known to those skilled in the art can be used to cool the heat-insulated component to room temperature. In the present invention, the cooling is preferably air cooling.

[0053] The present invention does not specifically limit the separation method; any separation method known to those skilled in the art can be used to separate the different layered composite sheets. In the present invention, the separation method preferably involves trimming the edges of the cooled composite sheet. In the present invention, the aforementioned separation method allows for the removal of the spot-welded portions. Since a release agent is applied between the different composite sheets, the different layered composite sheets can be naturally separated after the spot-welded portions are removed.

[0054] The present invention rolls stainless steel plates into single-sided corrugated plates of different thicknesses as upper and lower substrates, and casts high chromium cast iron between the corrugated interfaces of the upper and lower substrates to obtain a composite slab. The presence of the corrugations can improve the bonding strength between the layers; the composite slabs are then assembled into rolled slabs in a mirror-symmetrical manner and then hot-rolled. This can, on the one hand, ensure the straightness of the rolled plate shape; on the other hand, by coating an isolation agent between the composite slabs, the composite slabs are separated after hot rolling and heat preservation, so that multiple layered composite plates can be obtained, thereby improving production efficiency; the present invention utilizes hot rolling and heat preservation to complete metallurgical composite of the stainless steel substrate and the high chromium cast iron, and reduce stress damage to the brittle high chromium cast iron; the thinner stainless steel layer in the layered composite plate prepared by the method provided by the present invention is first used as a working surface, and after the surface is worn, the high chromium cast iron layer with excellent wear resistance is exposed, further exerting its wear-resistant effect, thereby achieving the purpose of improving its impact toughness without changing the wear resistance of the high chromium cast iron.

[0055] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0056] Example 1

[0057] A method for preparing a high-chromium cast iron and stainless steel layered composite plate, comprising the following steps:

[0058] (1) A 304 stainless steel plate is rolled into single-sided corrugated plates with a thickness of h of 5 mm and a thickness of H of 10 mm on a flat rolling mill with a corrugated roller as the upper roller and a flat roller as the lower roller, respectively. The single-sided corrugated plate with h of 5 mm is the upper base plate, and the single-sided corrugated plate with H of 10 mm is the lower base plate; the h is 20% of the H; the upper base plate and the lower base plate are single-sided corrugated plates, the corrugation height d of the lower base plate of the single-sided corrugated plate is 2 mm, and the corrugation height d is 20% of the thickness of the lower base plate; the corrugation width t of the lower base plate of the single-sided corrugated plate is 8 mm, satisfying t=4d; the corrugation height d on the base plate of the single-sided corrugated plate is 1 mm, and the corrugation height d is 20% of the thickness of the upper base plate; the corrugation width t on the base plate of the single-sided corrugated plate is 4 mm, satisfying t=4d.

[0059] The structures of the upper substrate and the lower substrate prepared in this step are as follows: Figure 1 As shown, in Figure 1 In the figure, 1 is the upper substrate and 2 is the lower substrate;

[0060] (2) polishing and cleaning the corrugated surfaces of the upper substrate and the lower substrate obtained in step (1) to remove the oxide layer and contaminants, and then placing the polished and cleaned corrugated surfaces of the upper substrate and the lower substrate opposite to each other and separately in a vacuum casting chamber with a vacuum degree of 0.001 to 0.003 Pa, wherein the distance E between the highest point of the corrugated surface of the upper substrate and the lowest point of the corrugated surface of the lower substrate is 8 mm; preheating the upper and lower substrates at 450° C.; casting a KmTBCr26 high chromium cast iron melt with a temperature of 1450° C. between the upper and lower substrates, and then cooling to obtain a composite slab;

[0061] Among them, the structure of the composite slab is as follows Figure 2 As shown, in Figure 2 In the middle, 3 is the high chromium cast iron layer, and 4 is the composite slab;

[0062] (3) stacking two composite slabs obtained in step (2) in a mirror-symmetrical manner, applying a 2 mm thick isolation agent between the two upper substrates; spot welding the two upper substrates to assemble them into a rolled slab, then placing the rolled slab in a heating furnace and heating it to 1180° C., starting hot rolling on a flat roll mill, the final rolling temperature being not less than 1100° C., the plastic deformation temperature of high chromium cast iron, the maximum reduction per hot rolling pass being 10%, the total deformation of hot rolling being 30%, and the rolling speed being 0.1 m / s; after rolling, the composite plate is kept at 700° C. for 30 min and subjected to diffusion heat treatment; after air cooling, the composite plate is trimmed on all sides, and the upper and lower composite plates are naturally separated to obtain two high chromium cast iron and stainless steel layered composite plates;

[0063] Among them, rolled slabs such as Figure 3 As shown, in Figure 3 In the figure, 5 is a separator, 6 is a rolled slab; high chromium cast iron and stainless steel layered composite plate such as Figure 4 As shown, in Figure 4 Among them, 7 and 7' are two high chromium cast iron and stainless steel layered composite plates.

[0064] Example 2

[0065] The difference from Example 1 is that in step (1), the corrugation height d of the lower substrate of the single-sided corrugated plate is 3 mm, which is 30% of the thickness of the lower substrate; the corrugation width t of the lower substrate of the single-sided corrugated plate is 12 mm, which satisfies t = 4d. The corrugation height d of the upper substrate of the single-sided corrugated plate is 1.5 mm, which is 30% of the thickness of the upper substrate; the corrugation width t of the upper substrate of the single-sided corrugated plate is 6 mm, which satisfies t = 4d.

[0066] Example 3

[0067] The difference from Example 1 is that in step (1), the corrugation height d of the lower substrate of the single-sided corrugated plate is 5 mm, which is 50% of the thickness of the lower substrate; the corrugation width t of the lower substrate of the single-sided corrugated plate is 20 mm, which satisfies t = 4d. The corrugation height d of the upper substrate of the single-sided corrugated plate is 2.5 mm, which is 50% of the thickness of the upper substrate; the corrugation width t of the upper substrate of the single-sided corrugated plate is 10 mm, which satisfies t = 4d.

[0068] Comparative Example 1

[0069] A method for preparing a high-chromium cast iron and stainless steel layered composite plate, comprising the following steps:

[0070] (1) A 304 stainless steel plate with a thickness of h (5 mm) was used as the upper substrate; a 304 stainless steel plate with a thickness of H (10 mm) was used as the lower substrate;

[0071] (2) The upper substrate and the lower substrate obtained in step (1) are relatively separated and fixedly placed in a vacuum casting chamber with a vacuum degree of 0.001 to 0.003 Pa, and the distance E between the upper substrate and the lower substrate is 8 mm; the upper and lower substrates are preheated at 450° C.; a KmTBCr26 high chromium cast iron melt with a temperature of 1450° C. is cast between the upper substrate and the lower substrate, and then cooled to obtain a composite slab;

[0072] (3) placing the substrate surfaces of two composite slabs obtained in step (2) facing each other and separated, and applying a 2 mm thick isolation agent between the two upper substrates; spot welding the two upper substrates to assemble them into a rolled slab, and then placing the rolled slab in a heating furnace to heat it to 1180° C., and starting hot rolling on a flat roll mill, with the final rolling temperature being not less than 1100° C., the plastic deformation temperature of high chromium cast iron, the maximum reduction per hot rolling pass being 10%, the total deformation of hot rolling being 60%, and the rolling speed being 0.1 m / s; after rolling, the composite plate is kept at 700° C. for 30 min and subjected to diffusion heat treatment; after air cooling, the four sides of the composite plate are trimmed, and the upper and lower composite plates are naturally separated to obtain two high chromium cast iron and stainless steel layered composite plates.

[0073] Test Case

[0074] The high chromium cast iron and stainless steel layered composite plates prepared in Examples 1 to 3 and Comparative Example 1 were tested using a tensile shear test. The bonding strengths of the high chromium cast iron and stainless steel layered composite plates were shown in Table 1.

[0075] Table 1 Bonding strength of high chromium cast iron and stainless steel layered composite plates prepared in Examples 1 to 3 and Comparative Example 1

[0076] Example 1 Example 2 Example 3 Comparative Example 1 Bonding strength 406.2Mpa 497.6Mpa 532.5Mpa 239.5Mpa

[0077] From the above results, it can be seen that the high chromium cast iron and stainless steel layered composite plate prepared by the method provided by the present invention can significantly improve the bonding strength between the high chromium cast iron and the stainless steel layer, thereby improving the toughness of the high chromium cast iron without changing the hardness and wear resistance of the high chromium cast iron.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a high chromium cast iron and stainless steel layered composite plate, comprising the following steps: (1) rolling a stainless steel plate into a single-sided corrugated plate of different thicknesses, which are used as an upper substrate and a lower substrate respectively; the thickness of the upper substrate is 10% to 90% of the thickness of the lower substrate; (2) placing the corrugated surfaces of the upper substrate and the lower substrate obtained in step (1) opposite to each other and separated, and then casting high chromium cast iron between the upper substrate and the lower substrate to obtain a composite slab; (3) assembling a plurality of composite slabs obtained in step (2) into a rolled slab, and then sequentially hot rolling, heat preservation, cooling, and separation to obtain a high-chromium cast iron and stainless steel layered composite plate; the assembling comprising: stacking the plurality of composite slabs in a mirror-symmetrical manner, and coating a release agent between the composite slabs; The material of the stainless steel plate in step (1) includes 316 stainless steel, 321 stainless steel or 430 stainless steel; The high chromium cast iron in step (2) includes KmTBCr12, KmTBCr15Mo or KmTBCr20Mo; The end point temperature of the hot rolling in step (3) is not less than 1100°C.

2. The preparation method according to claim 1, characterized in that The corrugated cross section of the single-sided corrugated plate in step (1) is arc-shaped, elliptical, sinusoidal, triangular, trapezoidal or rectangular.

3. The preparation method according to claim 1 or 2, characterized in that The corrugation height d in step (1) is 20% to 50% of the thickness of the corresponding substrate.

4. The preparation method according to claim 3, characterized in that The corrugation height d and the corrugation width t of the single-face corrugated plate satisfy t=(1-5)d.

5. The preparation method according to claim 1, characterized in that The step (2) also includes preheating the upper substrate and the lower substrate at 400-500° C. before casting.

6. The preparation method according to claim 1, characterized in that In the step (3), the reduction in each hot rolling pass is 10% to 30%.

7. The preparation method according to claim 1, characterized in that The insulation temperature in step (3) is 600-800° C., and the insulation time is 20-60 minutes.

Images