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150KN Bollard Related Defect Experience
- 2020-03-20-

150KN bollards often show some defects during the casting process. Barrett Yangzhou fender manufacturers summarized the experience of casting bollards for many years and summarized a series of bollard defects:

1. 150KN bollard defect: a hole type defect formed by gas in the bollard casting. Its surface is generally smooth, mainly pear-shaped, round and oval. Generally, the surface of the casting of the bollard is no longer exposed, large holes are often isolated, and small holes are presented in groups.

2.Fire defect of 150KN bollard casting: a large amount of gas generated during the pouring process cannot be smoothly discharged, boiling occurs in the metal liquid, causing a large number of pores in the bollard casting, so that the defect of the bollard casting is incomplete. .

3.150KN bollard casting pinhole defects: hole-type casting defects resulting from the combination of dispersion and shrinkage and shrinkage. Generally, the size of the needle is distributed in the pores of the bollard casting. Aluminum alloy bollard castings often show such pores, which is very harmful to bollard castings. Dispersive pores distributed in groups on the surface of the bollard casting. Its characteristics and formation are the same as those of subcutaneous pores. It is usually exposed on the bollard casting surface and can be taken out after machining 1-2mm.

4. Subcutaneous pore defects of 150KN bollard castings: Dispersive pores located on the surface of bollard castings. Resonant stomata produced by chemical reactions between metal liquids and sand molds. There are needle-shaped, pin-shaped, spherical, etc. They vary in size and depth. It is usually found after machining or thermal processing.

5.150KN shrinkage defects of bollard castings: holes in bollard castings due to poor shrinkage during solidification. The shape is extremely irregular, with rough walls and dendritic crystals, which often appear as solidified parts of today's bollard castings. Scattered and small shrinkage holes appearing on the cross section of the bollard casting. The shrinkage found only with the help of a high magnifying glass is called microcontraction. The part of the bollard casting with shrinkage defects may ooze during the air tightness test.

The 150KN bollards are designed and selected according to the berth talents and the structure of the wharf, which can meet the requirements of the ship's departure, docking, berthing, and number one operations. The bollard consists of the shell, anchor rods, nuts, washers, anchor plates and core packing. The bollard is divided into cast iron (HT200) and cast steel (ZG230-450).