Curved gi sheet

Curved gi sheet is a metal sheet that combines curved structure and galvanized protective layer,widely used in fields such as building decoration,automobile manufacturing,and home appliance production.Its production process mainly includes key links such as raw material preparation,sheet forming,galvanizing treatment,and quality inspection.

1. Raw material preparation

1.Substrate selection:Cold rolled steel plates or hot-rolled pickled steel plates are usually used as substrates for curved gi sheet.Cold rolled steel plates have high surface flatness and good thickness accuracy,making them suitable for products with high requirements for surface quality and forming accuracy;Hot rolled pickled steel plates have a lower cost and are suitable for general use products with relatively low surface quality requirements.Select appropriate steel grades and specifications based on the specific purpose and performance requirements of the product,such as Q235,SPCC,etc.

2.Raw material inspection:Strictly inspect the incoming substrates,including dimensional measurement(checking whether the thickness,width,and length of the board meet the requirements),surface quality inspection(checking for defects such as cracks,holes,rust spots,etc.),and mechanical performance testing(testing the strength,toughness,and other performance indicators of the substrate through tensile testing,bending testing,etc.).Only substrates that pass inspection can enter the subsequent production process,ensuring the quality of raw materials is the foundation for ensuring product quality.

2. Sheet metal forming

1.Mold design and manufacturing:Design and manufacture molds according to the design requirements of curved gi sheets.The accuracy and quality of the mold directly affect the forming effect of the sheet metal.It is necessary to accurately calculate the curvature,size,and structure of the mold,use high-quality mold steel materials,and perform high-precision processing through CNC machining equipment to ensure the dimensional accuracy and surface quality of the mold.
2.Roll forming:Roll forming is one of the commonly used methods for producing gi sheets.The substrate is fed into the roll forming unit,and the sheet is gradually bent and deformed by multiple sets of rollers of different shapes to achieve the desired arc shape.During the rolling process,it is necessary to strictly control the parameters such as the speed,pressure,and temperature of the rollers to ensure the forming accuracy and surface quality of the sheet metal.At the same time,according to the material and thickness of the sheet,adjust the gap and bending angle of the rollers reasonably to avoid defects such as cracking and wrinkling of the sheet.
3.Stamping forming:For some curved gi sheet products with complex shapes and high precision requirements,stamping forming technology can be used.Place the substrate in the stamping die and apply pressure through a press to cause plastic deformation of the sheet metal under the action of the die,thereby obtaining the desired arc-shaped shape.During the stamping process,attention should be paid to the installation accuracy of the mold and the pressure control of the press to ensure the dimensional accuracy and forming quality of the product.In addition,it is necessary to perform subsequent treatments such as deburring and shaping on the stamped sheet metal to improve the surface quality of the product.

4.Bending forming:Using bending equipment such as bending machines,rolling machines,etc.,to bend the substrate into an arc shape.Bending forming is suitable for the production of curved gi sheets with larger curvature radii and relatively simple shapes.During the bending process,it is necessary to select appropriate bending molds and bending process parameters based on the material and thickness of the board,such as bending angle,bending radius,etc.,to ensure the bending quality and forming accuracy of the board.At the same time,attention should be paid to preventing rebound of the board during the bending process,which can be solved by increasing the bending angle appropriately or adopting a correction process.

3. Galvanized treatment

1.Pre treatment:Before galvanizing,the formed sheet needs to be pre treated to remove impurities such as oil stains,rust,and dust on the surface,and improve the adhesion between the galvanized layer and the sheet substrate.The pre-treatment process usually includes steps such as degreasing,acid washing,water washing,and activation.Defatting is the use of chemical agents to remove oil stains from the surface of the board;Acid washing is the process of dissolving rust and oxide scale on the surface of a sheet using acid solution;Water washing is to clean the residual chemicals after degreasing and acid washing;Activation is the formation of an active film on the surface of the sheet,which is beneficial for the deposition of the galvanized layer.
2.Hot dip galvanizing:Hot dip galvanizing is the process of immersing pre treated sheet metal in molten zinc solution to form a continuous and dense galvanized layer on the surface of the sheet metal.The process flow of hot-dip galvanizing is generally as follows:sheet metal is put into the pot→hot-dip galvanizing→air knife scraping zinc→cooling→passivation.During the hot-dip galvanizing process,it is necessary to strictly control parameters such as the temperature of the zinc solution,galvanizing time,and air knife pressure to ensure the thickness and uniformity of the galvanized layer.The temperature of the zinc solution is generally controlled between 450℃-465℃,and the immersion time depends on the thickness and material of the sheet,usually 1-3 minutes.The function of using an air knife to scrape zinc is to remove excess zinc liquid from the surface of the sheet,ensuring that the thickness of the galvanized layer meets the requirements and making the surface smoother.The cooling process can use water or air cooling to quickly cool the galvanized sheet to room temperature to prevent oxidation and deformation of the galvanized layer.Passivation treatment is the formation of a passivation film on the surface of the galvanized layer to improve its corrosion resistance and weather resistance.
3.Electrogalvanizing:Electrogalvanizing is the process of depositing a layer of zinc on the surface of a sheet using electrochemical principles.The process flow of electroplating mainly includes:degreasing→water washing→acid washing→water washing→electroplating→water washing→passivation.Compared with hot-dip galvanizing,the thickness of the electroplated zinc layer is thinner,generally between 5-30μm,but the surface of the electroplated zinc layer is smoother and flatter,and can be galvanized on one or both sides according to product requirements.In the process of electroplating zinc,it is necessary to control the composition,temperature,current density and other parameters of the plating solution to ensure the quality and performance of the galvanized layer.The electroplating solution mainly contains zinc salts,complexing agents,additives,and other components.By adjusting the proportion and concentration of these components,galvanized layers with different properties can be obtained.
4.Post treatment:Galvanized sheet metal also needs to undergo post treatment to further improve product performance and quality.The post-treatment process mainly includes anti white rust treatment,oil coating,color coating,etc.Anti white rust treatment is to prevent the occurrence of white rust on the galvanized layer in humid environments.Chemical treatment or coating with anti rust paint can be used.Oil coating is the process of applying a layer of rust proof oil to the surface of galvanized sheet,which serves to protect the galvanized layer and prevent scratches during transportation and storage.Color coating is a process of applying a layer of colored organic coating on the surface of galvanized sheet,which enhances its decorative and corrosion-resistant properties.It is widely used in fields such as construction and home appliances.
The above is the overall production process of curved gi sheet.If you want to have a deeper understanding of any aspect or have any other modification or supplementary requirements,please feel free to let us know at any time.