Purpose of sheet metal:
There are a lot of sheet metal materials suitable for stamping. Sheet metal materials widely used in electronic and electrical industry include:
⒈ the common cold-rolled plate SPCC refers to the continuous rolling of steel ingot into the required thickness of steel coil or sheet. SPCC surface without any protection, exposed to the air is very easy to be oxidized, especially in humid environment, oxidation speed is accelerated, dark red rust appears, the surface should be painted, electroplated or other protection.
- The base material of SECC SECC galvanized steel sheet is a common cold-rolled steel coil. After degreasing, pickling, electroplating and various post-treatment processes in the continuous electro galvanizing production line, it becomes the electro galvanized product. SECC not only has the mechanical properties and approximate processability of general cold-rolled steel sheet, but also has superior corrosion resistance and decorative appearance. In the market of electronic products, home appliances and furniture, it is very competitive and replaceable. For example, SECC is widely used in computer cases.
- Hot dip galvanized steel sheet SGCC hot-dip galvanized steel coil refers to the semi-finished products after hot-rolled pickling or cold-rolled, which are cleaned and annealed, immersed in the solution zinc bath at about 460 ° C, and the steel sheet is coated with zinc layer, and then quenched, tempered, leveled and chemically treated. SGCC material is harder than SECC material, with poor ductility (avoiding deep drawing design), thicker zinc layer and poor weldability.
- The content of Cr (CR) in SUS301 is lower than that in SUS304, and its corrosion resistance is poor. However, after cold working, it can obtain good tensile strength and hardness, and has good elasticity. It is mostly used in spring spring and anti EMI.
- Stainless steel SUS304 is one of the most widely used stainless steels. Because it contains Ni (nickel), it is more corrosion-resistant and heat-resistant than the steel containing Cr (CR). It has very good mechanical properties, no heat treatment hardening phenomenon and no elasticity.
2、 Features of sheet metal:
Sheet metal, B ǎ N J ī n (metal plate; Sheet metal in English) has not yet had a relatively complete definition. According to a definition in a foreign professional journal, it can be defined as: sheet metal is a comprehensive cold working process for sheet metal (usually less than 6 mm), including shearing, punching / cutting / compounding, folding, welding, riveting, splicing, forming (such as automobile body), etc. Its remarkable feature is that the thickness of the same part is the same.
Sheet metal has the characteristics of light weight, high strength, conductive (can be used for electromagnetic shielding), low cost, good mass production performance and so on. It has been widely used in the fields of electronic appliances, communication, automobile industry, medical equipment, etc., for example, in computer case, mobile phone, MP3, sheet metal is an essential part. With the application of sheet metal more and more widely, the design of sheet metal has become a very important part in the process of product development. Mechanical engineers must master the design skills of sheet metal parts, so that the designed sheet metal can not only meet the requirements of product function and appearance, but also make the stamping die manufacturing simple and low cost.
Sheet metal processing is the key technology that sheet metal technical staff need to grasp, and it is also an important process of sheet metal forming. Sheet metal processing includes the traditional cutting and blanking, blanking processing, bending and pressing forming and other methods and process parameters, as well as various cold stamping die structures and process parameters, various equipment working principles and operation methods, as well as new stamping technology and new technology. Parts sheet metal processing is called sheet metal processing.
What should we pay attention to when we look at the sheet metal processing plant.
The unfolded drawing of sheet metal processing plant is based on the part drawing
- If there are mistakes (similar and asymmetric), it should be highlighted
- Reasonable selection of clearance and hemming methods: clearance 0.3 below T = 2.0, 0.5 clearance between T = 2-3, and long edge wrapping with short edge (door panel)
- The deployment method should be suitable, convenient, material saving and processability
- Burr direction
- Draw the sectional view according to the position and direction of tooth extraction, riveting, tearing and bumping
- Check the material, plate thickness and plate thickness tolerance
- The place to be protected by spraying must be indicated
- Enlarge the drawing where the size is large
- For special angle, the inner radius of bending angle (generally r = 0.6) should be tested and unfolded
- Reasonable consideration of tolerance dimensions: negative difference goes to the end
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