Thermoformed component having excellent coating adhesion, and manufacturing method therefor

Abstract

Disclosed are thermoformed component having excellent coating adhesion and a method for manufacturing the same. The thermoformed component comprises a substrate layer and an aluminum coating coated on at least one surface of the substrate layer, wherein the average roughness Ra of a surface of the thermoformed component is between 1.0 μm and 3.0 μm, the peak height and the peak-to-valley height Rt are between 8 μm and 30 μm, and the roughness peak count Rpc is greater than or equal to 50. The thermoformed component has good paintability, good coating adhesion and good corrosion resistance, and is very suitable for automotive parts.

1 . A thermoformed component having excellent coating adhesion, comprising a substrate layer and an aluminum coating coated on at least one surface of the substrate layer, wherein the average roughness Ra of a surface of the thermoformed component is 1.0˜3.0 μm, the peak-to-valley height Rt is 8˜30 μm, and the roughness peak count Rpc is ≥50. 
     
     
         2 . The thermoformed component having excellent coating adhesion according to  claim 1 , wherein the aluminum coating comprises a diffusion layer adjacent to the substrate layer and an alloy layer on the surface of the aluminum coating, wherein the ratio of the thickness of the diffusion layer to the total thickness of the aluminum coating is 0.08-0.5. 
     
     
         3 . The thermoformed component having excellent coating adhesion according to  claim 1 , wherein the thickness of the diffusion layer is ≤16 μm, and the total thickness of the aluminum coating is ≤60 μm. 
     
     
         4 . The thermoformed component having excellent coating adhesion according to  claim 1 , wherein the mass percentage of chemical elements of the aluminum coating is: Si: 4˜14%, Fe: 0˜4%, Mg: 0˜10%, Zn: 0˜20%, and a balance of Al and other unavoidable impurities. 
     
     
         5 . The thermoformed component having excellent coating adhesion according to  claim 1 , wherein the average weight of the aluminum coating is 20˜120 g/m 2  per single surface. 
     
     
         6 . The thermoformed component having excellent coating adhesion according to  claim 5 , wherein the average weight of the aluminum coating is 30˜100 g/m 2  per single surface. 
     
     
         7 . The thermoformed component having excellent coating adhesion according to  claim 1 , wherein the mass percentage of chemical elements of the substrate layer is:
 C: 0.01˜0.8%, Si: 0.05˜1.0%, Mn: 0.1˜5%, P≤0.3%, S0.1%, Al≤0.3%, Ti≤0.5%, B: 0.0005˜0.1%, Cr: 0.01˜3%, Nb≤0.5%, V≤0.5%, and a balance of Fe and other unavoidable impurities.   
     
     
         8 . The thermoformed component having excellent coating adhesion according to  claim 7 , wherein the mass percentage of chemical elements of the substrate layer further meets at least one of the following:
 C: 0.05˜0.6%,   Si: 0.07˜0.8%,   Mn: 0.3˜4%,   P≤0.2%,   S≤0.08%,   A≤0.2%,   Ti≤0.4%,   B: 0.0005˜0.08%,   Cr: 0.01˜2%,   Nb≤0.3%,   V≤0.3%.   
     
     
         9 . The thermoformed component having excellent coating adhesion according to  claim 7 , wherein the mass percentage of chemical elements of the substrate layer further meets at least one of the following:
 C: 0.15˜0.5%,   Si: 0.1˜0.5%,   Mn: 0.5˜3%,   P≤0.1%,   S≤0.05%,   A≤0.1%,   Ti≤0.2%,   Cr: 0.01˜1%.   
     
     
         10 . The thermoformed component having excellent coating adhesion according to  claim 1 , wherein the yield strength of the thermoformed component having excellent coating adhesion is 400˜1400 MPa, the tensile strength is 500˜2100 MPa, and the elongation is ≥4%. 
     
     
         11 . The thermoformed component having excellent coating adhesion according to  claim 1 , wherein the surface of the thermoformed component having excellent coating adhesion comprises Fe 2 Al 5  and FeAl alloy; or the surface of the thermoformed component having excellent coating adhesion mainly consists of Fe 2 Al 5  and FeAl alloy, and further comprises silicon oxide, aluminum oxide and iron oxide. 
     
     
         12 . The thermoformed component having excellent coating adhesion according to  claim 9 , wherein the volume percentage of martensite in the microstructure of the substrate layer of the thermoformed component having excellent coating adhesion is 95%. 
     
     
         13 . A manufacturing method for the thermoformed component having excellent coating adhesion of  claim 1 , comprising the following steps:
 (1) immersing a substrate in an aluminum coating solution to obtain a plate having an aluminum coating on a surface thereof;   (2) leveling: using a leveling roller having a roughness Ra of 0.5˜3.0 μm to level the plate, and controlling the leveling elongation ≤2.0%, wherein the surface thermal radiation coefficient of the plate is 0.1˜0.8, the surface roughness Ra of the plate is 0.3˜2.0 μm, and the peak roughness count RPC of the surface of the plate is 30˜150;   (3) blanking: performing blanking on the plate or cutting the plate to obtain a blank having a required component shape;   (4) heat treatment: putting the blank into a heating furnace for heating and heat preservation, wherein the temperature of the heating furnace is 880˜960° C., the atmosphere in the heating furnace is air or nitrogen, and the residence time of the blank in the heating furnace is 2.5˜10 min;   (5) transferring and hot stamping: quickly transferring the heated blank to a mold for cooling and stamping forming to form the thermoformed component.   
     
     
         14 . The manufacturing method according to  claim 13 , wherein in step (1), the mass percentage of chemical elements of the aluminum coating solution is: Si: 5˜11%, Fe: 2˜4%, Zn: 0˜15%, Mg: 0˜8%, and a balance of Al and other unavoidable impurities. 
     
     
         15 . The manufacturing method according to  claim 13 , wherein in step (4), during the heating up process of blank heating, the heating rate does not exceed 10° C./s in the range of heating up to 400˜600° C. 
     
     
         16 . The manufacturing method according to  claim 13 , wherein in step (5), the blank is transferred to the mold within 20 seconds; or after the mold is closed, a pressure holding quenching is continued for 4˜20 s, and the pressure holding pressure applied to the blank surface is ≥8 MPa; or the closing speed of the mold during stamping is 30˜150 mm/s; or the blank is cooled to 50˜200° C. at a cooling rate of 30˜150° C./s. 
     
     
         17 . (canceled) 
     
     
         18 . The manufacturing method according to  claim 13 , wherein the material of the mold meets the following requirement: the thermal diffusion coefficient at 700° C. is greater than 3.8 mm 2 /s. 
     
     
         19 .- 20 . (canceled) 
     
     
         21 . The manufacturing method according to  claim 13 , wherein the mass percentage of chemical elements of the substrate layer is:
 C: 0.01˜0.8%, Si: 0.05˜1.0%, Mn: 0.1˜5%, P≤0.3%, S≤0.1%, Al≤0.3%, Ti≤0.5%, B: 0.0005˜0.1%, Cr: 0.01˜3%, Nb≤0.5%, V≤0.5%, and a balance of Fe and other unavoidable impurities.   
     
     
         22 . The manufacturing method according to  claim 13 , wherein the aluminum coating comprises a diffusion layer adjacent to the substrate layer and an alloy layer on the surface of the aluminum coating, wherein the ratio of the thickness of the diffusion layer to the total thickness of the aluminum coating is 0.08-0.5. 
     
     
         23 . The thermoformed component having excellent coating adhesion according to  claim 4 , wherein the mass percentage of chemical elements of the aluminum coating is: Si: 4˜14%, Fe: 2˜4%, Mg: 0˜10%, Zn: 0˜20%, and a balance of Al and other unavoidable impurities.