Galvanized sheet cracks during bending? 4 key parameters to avoid processing defects

During the processing of galvanized sheets, bending cracking is a common and thorny problem, which will seriously affect product quality and production efficiency. To avoid such processing defects, the following four key parameters need to be strictly controlled:

1. Material quality
Material quality is the basic factor affecting the bending performance of galvanized sheets. If there are obvious defects such as defects, inclusions, pores, etc. inside the galvanized sheet, or the galvanized layer is thin and the adhesion between the internal substrate and the galvanized layer is not strong, cracking is very likely to occur during the bending process. Therefore, when purchasing galvanized sheets, suppliers with reliable quality and good reputation should be selected, and the quality of raw materials should be strictly checked to ensure that they meet relevant standards and requirements.

2. Bending process
Bending radius: A bending radius that is too small will cause the galvanized layer on the surface of the galvanized sheet to crack and peel off, thereby affecting its corrosion resistance. Generally speaking, there is a certain proportional relationship between the thickness of the galvanized sheet and the minimum bending radius. For example, for ordinary galvanized sheets with a thickness between 0.5 and 1.5 mm, the minimum bending radius is usually recommended to be no less than 1-2 times the thickness of the sheet. This is because both the galvanized layer and the substrate undergo tensile and compressive deformation during the bending process. If the bending radius is too small and the deformation is too concentrated, the galvanized layer is easily damaged.
Bending angle: The accuracy of the bending angle is also an important requirement. In many product manufacturing, such as metal furniture, electrical appliance housing, etc., the angle of the galvanized sheet after bending needs to be precisely controlled. This requires extra care in the selection and commissioning of bending forming equipment. Advanced CNC bending machines can accurately control the bending angle through pre-set programs, and the error can be controlled within a very small range.
3. Product design
If the structural design of the galvanized sheet is not standardized, or the product size exceeds the tolerance range of the material strength, bending and cracking are also prone to occur. Therefore, in the design stage, the material properties and processing technology of the galvanized sheet should be fully considered, and the structure and size of the product should be reasonably determined. For example, for parts that need to be bent, the fillet radius should be appropriately increased to avoid sharp bending angles; at the same time, the force of the product should be reasonably distributed to avoid local stress concentration.

4. Processing environment and operation
Processing environment: Factors such as humidity and temperature in the processing environment may also affect the bending performance of the galvanized sheet. For example, in a humid environment, the surface of the galvanized sheet easily absorbs moisture, resulting in a decrease in the adhesion between the galvanized layer and the substrate during bending, thereby increasing the risk of cracking. Therefore, the processing environment should be kept dry and clean, and the temperature and humidity should be controlled.
Operation specifications: The skill level and degree of operation specifications of the operator will also affect the bending quality. The operator should undergo professional training, be familiar with the characteristics of the galvanized sheet and the bending process requirements, and operate in strict accordance with the operating procedures. During the bending process, pay attention to controlling the bending speed and pressure to avoid cracking of the galvanized sheet due to improper operation.