The Causes and Remedies of Riveting Earring Defects of Steel Products
Riveting earring defects of steel products is a typical surface quality defect. Appearing in the form of round convex arc, it looks like the clip of earrings.
Cause Analysis
There are many factors, which cause the riveting earring defects of steel products. The most common factors are welding, forging, and structure.
Welding errors: The quality of welded joint can be directly affected by welding current, arc length, arc shape, arc arrangement, welding parameters, flux adhesion and other factors, which could lead to the formation of riveting.
Forging defects: Uneven cooling after forging, air rapid cooling and cooling cause uneven stress of some part of the surface of steel, which results in the riveting of some part of the surface, finally forming the large earring-shaped defects.
Structural Reasons: Riveting earring defect is a crystalline phenomenon, which is caused by the shrinkage of material structure during crystallization and solidification. For example, in the process of smelting steel ingot, the arrangement of cells is uneven, resulting in a lower melting point at some positions. At the time of casting, if there are conditions such as poured improperly, poorly airtight and cooling too fast, the internal stress of steel will increase. During the further working process, under the elastic recovery of steel, the stress can be relieved, forming riveting earring defects in the material surface.
Measuring Measures
1. Resolving welding error
In order to eliminate welding errors, first of all, it is necessary to troubleshoot the welding source, analyze the operation conditions and welding parameters and carry out the preventive measures. Secondly, it is necessary to adjust the arc length and arc type correctly, ensure the stability of welding parameters, and reduce the negative factors caused by other factors such as oxide adhesion and current intensity.
2. Properly carried out air cooling process
Riveting earring defect can be avoided and reduced by air cooling process. During air cooling process, the cooling airflow should be uniform and the temperature should be reduced.
3. Properly arranged pouring
Properly arrange and control pouring time and place to reduce internal stress.
4. Properly designing smelting furnace
The feed rate, steel temperature and furnace air must be adjusted correctly, making sure that the overall temperature in the furnace is uniform and the steel is fully melted.
The above introduction on the causes and remedies of riveting earring defects of steel products is for everyone to understand and discuss. If the above measures cannot be effectively resolved, welcome to consult Hebei Boyang Metals and Minerals Co.,Ltd. We have professional engineers and technicians who can provide personalized services to solve your problems.
