1. Key points of raw material quality control
Selection basis: Select metal sheets according to product requirements, while considering the supplier's reputation and actual situation. For example, in sheet metal processing, commonly used metal sheets include steel plates, stainless steel plates, aluminum plates, etc. The appropriate sheet type should be determined based on the purpose and performance requirements of the final product1.
Quality verification: When purchasing, the raw material report provided by the supplier must be verified to ensure that the quality of the raw materials meets the requirements. This includes checking whether the material composition and mechanical properties of the sheet meet the corresponding standards.
2. Key points of equipment quality control
Equipment selection: Select processing equipment with reliable quality and stable performance, such as shearing machines, bending machines, punching machines, etc. The accuracy and stability of these equipment will directly affect the quality of metal sheet processing. For example, high-precision shearing machines can ensure the accuracy of sheet cutting dimensions.
Maintenance: Regularly maintain and maintain the equipment to ensure that the equipment is in normal operation. Wear and failure of the equipment may lead to processing errors. For example, wear of the mold of the bending machine may cause inaccurate bending angles.
Staff training: Operators must undergo professional training, master the operating skills of the equipment, and improve their operating level. Skilled operation can reduce processing quality problems caused by human factors. For example, correct stamping operation can avoid defects such as scratches on the surface of the plate.
3. Key points of quality control in the production process
Cutting link
Dimensional accuracy: accurately cut metal plates according to design requirements, and control the deviation of cutting dimensions within the allowable range. For example, in steel formwork processing, the material should be cut accurately. For parts with assembly requirements, the accuracy of cutting dimensions directly affects the subsequent assembly accuracy.
Cutting surface quality: ensure the flatness and smoothness of the cutting surface, and avoid roughness, notches, etc. This may affect the quality of subsequent welding, bending and other processes. For example, uneven cutting surface will lead to poor fit during welding.
Bending link
Angle accuracy: accurately control the bending angle to meet product design requirements. This requires adjusting the parameters of the bending machine according to factors such as the material and thickness of the plate. For example, when processing some metal components with strict angle requirements, excessive deviation may cause the components to be unable to be assembled normally1.
Bending line quality: the bending line should be clear and straight, avoiding problems such as bending and discontinuity of the bending line to ensure the appearance and structural strength of the product.
Pressing stage
Pressure control: Reasonably control the pressing pressure to prevent excessive deformation or cracks of the plate due to excessive pressure. If the pressure is too low, the expected pressing effect may not be achieved. For example, when pressing some metal plates with special shape requirements, pressure control is particularly critical1.
Shape accuracy: Ensure that the shape of the plate after pressing is consistent with the design shape. For the pressing of complex shapes, use a suitable mold and ensure the accuracy of the mold
Welding stage
Welding process selection: Select a suitable welding process according to the material and thickness of the plate. For example, argon arc welding and other processes may be used for stainless steel plates to ensure welding quality2.
Welding quality: Ensure that the welding is firm and free of defects such as pores, slag inclusions, and cracks. Welding quality directly affects the structural strength of metal sheet products. For example, in architectural metal products, welding defects may cause safety hazards.
IV. Key points for finished product quality control
Appearance inspection
Surface flatness: Check whether the surface of the metal sheet after processing is flat and smooth, without obvious bumps and bumps. For example, in architectural metal products, uneven surfaces may affect the appearance and subsequent installation and use.
Scratches and burrs: Check whether there are scratches and burrs on the surface. These defects may affect the performance and safety of the product. For example, in the processing of metal shells of some precision instruments, scratches and burrs are not allowed.
Rust: Check whether there is rust, especially for some metal sheet products that need to be used for a long time or in special environments. Rust will reduce their service life and performance2.
Dimension inspection
Overall size: Measure whether the overall size of the finished product meets the design requirements, including dimensional deviations in length, width, height, etc. For example, in the processing of steel formwork, excessive dimensional deviation may cause the inability to be installed and used normally.
Hole size: For products with hole requirements, check whether the position, size, spacing, etc. of the holes are accurate. The accuracy of the hole position is very important for some metal products that need to be assembled. For example, the deviation of the connection hole position of mechanical parts may cause assembly failure.
Mechanical property inspection
Tensile strength: Check whether the tensile strength of the finished metal sheet meets the corresponding standard requirements. This is especially important for metal structural parts that bear tensile force. For example, metal components in bridges need to have sufficient tensile strength to ensure structural safety.
Yield strength: Check the yield strength to ensure that the deformation of the sheet is within the allowable range under a certain external force, which is related to the stability and safety of the product in actual use.
Elongation: Determine the elongation to understand the plastic deformation capacity of the metal sheet. For some products that require a certain deformation capacity, such as metal shell parts of automobiles, elongation is an important performance indicator.
Chemical composition inspection
Carbon content: Check whether the carbon content in the metal sheet meets the standard. The high or low carbon content will affect the hardness, toughness and other properties of the sheet. For example, high carbon steel has high hardness but relatively low toughness, and the carbon content needs to be controlled according to product requirements.
Silicon content, manganese content, etc.: Detect the content of other chemical components, such as silicon content, manganese content, etc. The content of these elements will also affect the performance of the sheet. For example, manganese can improve the strength and toughness of steel.
Metallurgical structure inspection
Grain size: Check whether the grain size of the metal sheet meets the standard requirements. The grain size will affect the mechanical properties of the sheet. For example, metal sheets with fine grains usually have higher strength and better toughness2.
Microstructure: Check the morphology and structure of the microstructure to ensure that it meets the performance requirements of the product. Different microstructures will give metal sheets different performance characteristics.
Nondestructive testing
Crack detection: Use nondestructive testing methods to check whether there are cracks in the finished metal sheet. Cracks will seriously affect the structural strength and safety of the product. For example, in metal sheet products in the aerospace field, even tiny cracks may lead to serious consequences.
Porosity and inclusion detection: Check whether there are defects such as pores and inclusions. These defects will reduce the quality and performance of metal sheets. For example, in the processing of some metal containers with high sealing requirements, the presence of pores is not allowed.
