Factors affecting the performance of GL AH32 steel plate include: chemical composition, melting and casting, rolling and heat treatment processes, etc., mainly chemical composition;
The content of sulfur and phosphorus directly affects the performance of GL AH32 steel plate in the thickness direction. Sulfur is the most severely segregated element in continuous casting slabs. Sulfur will cause the hot brittleness of GL AH32 steel plate, which will cause cracks in GL AH32 steel plate during high temperature forging. A lot of looseness and pores are produced during welding.
Phosphorus is an element with high segregation degree in the continuous casting slab of GL AH32 steel plate, second only to sulfur, and the diffusion rate of phosphorus in iron solid solution is very small, so it is difficult to eliminate the segregation of phosphorus, which seriously affects the performance of GL AH32 steel plate.
Phosphorus is dissolved in ferrite in the form of solid solution. This solid solution is very brittle. The phosphorus-rich zone formed makes the GL AH32 steel plate brittle and reduces the plasticity, toughness and weldability of the GL AH32 steel plate. It is easy to cause cracks in steel during hot working and cracks during welding.
Therefore, offshore platforms have strict requirements on the content of sulfur and phosphorus in the GL AH32 steel plate, and the content of sulfur is strictly controlled.
