Cause analysis of steel plate bulge defect:
1, production process problems
In the production process of steel plate, if the boiler water pressure is too high, it will produce too much hydrogen inside the steel plate and form pores. These pores pile up together to form a bulge defect. In addition, if the holding time is too long, the metal grains on the surface of the steel plate will be deformed, resulting in bulging on the surface.
2, processing technology problems
During the processing of the steel plate, if it is subjected to too much pressure or bending force, it will be deformed, resulting in bulging defects on the surface. In addition, the quality of the tool used in processing is poor, and the speed is too fast, which will also cause damage to the surface of the steel plate, thus forming a bulge defect.
3, the transportation process of the steel plate in the transportation process, if subjected to serious impact or extrusion, it will cause the surface bulge. Especially when the steel plate is shaken or bumpy during transportation, it is more likely to cause bulging defects.
The solution to the defect of steel plate belly:
1. Strengthen production management
Strengthening the management in the production process is the key to prevent the defects of the steel plate bulge, to control the boiler water pressure, to ensure the rationality of heating time, to avoid the production of too much hydrogen, grain deformation and other problems.
2, strengthen processing and testing technology
Strengthen the quality control of processing technology, use appropriate cutting tools, reasonable control of processing speed, to avoid damage to the surface of the steel plate during processing. In addition, the steel plate is strictly tested and screened to eliminate hidden dangers and reduce the incidence of bulge defects.
3. Strengthen transportation management
It is also important to strengthen the management and control of the transportation process, and it is necessary to fully package and fix it before transportation to prevent vibration or turbulence during transportation, resulting in defects of the steel plate belly.
The appearance of steel plate belly defects is a very common phenomenon, but as long as the management of production, processing and transportation links is strengthened, hidden dangers are controlled from the source, and the rational use of technical means and tools can effectively prevent and solve this defect problem, and improve the quality and efficiency of steel plates.
The common quality defects of steel plate are as follows:
1. Crack
Crack is one of the common defects of steel plate, mainly divided into hot crack and cold crack two categories. The hot crack is produced in the process of heat treatment or hot working of steel plate. The main reasons are large residual stress, coarse grain and uneven distribution of alloying elements in steel. Cold cracks are created during cold working, bending or forging. Cracks have a serious effect on the properties of steel plates, reducing the strength, toughness and corrosion resistance of steel plates.
2. Bubbles
Bubbles refer to the large and small pores inside the steel plate, mainly because the oxides or other impurities in the ingot are not completely removed when the molten steel is solidified. Bubbles will affect the strength and toughness of the steel plate, and may cause the steel plate to fracture or rupture during use.
3. Inclusions
Inclusion refers to foreign bodies or non-metallic inclusions in steel plates sandwicked between grains or grain boundaries, mainly because impurities such as sulfur and phosphorus in molten steel are not completely removed. It may also be caused by non-metallic substances entering molten steel during the production process. Inclusion will affect the toughness and strength of steel plate. For high strength steel plate, the influence of inclusions is more obvious.
4. Rust
Rust is the phenomenon of corrosion on the surface of the steel plate, mainly due to the destruction or corrosion of the covering layer on the surface of the steel plate. Rust will reduce the corrosion resistance and service life of the steel plate, and will cause the steel plate to lose its original function.
The above are common quality problems of steel plates, and the existence of these problems will seriously affect the performance and service life of steel plates. Therefore, relevant measures should be taken in the production and processing process to minimize the occurrence of these problems.