Why do some galvanized steel pipes bend more severely after water cooling?

When galvanized steel pipes with a temperature of around 300～350°C are conveyed into the water by a chain, the speed cannot be very fast. Due to the inherent longitudinal curvature of hot galvanized steel pipes, they may not come into contact with the cooling water surface simultaneously along their entire length. Therefore, the parts of the pipe that first come into contact with the cooling water undergo rapid contraction, causing the pipe to bend. Even after the entire galvanized steel pipe is submerged in the water, it cannot be corrected well. This is why galvanized steel pipes may appear to bend more severely after water cooling.