There are two reasons for the poor surface quality of SSAW steel pipes:
(1) The impurities of inferior spiral steel are not uniform.
(2) The manufacturer of inferior materials has poor guidance and protective equipment, and is easy to stick steel, which is easy to produce scars after these impurities bite.


The thin and low cross ribs of inferior spiral steel often have enough dissatisfaction, because the manufacturer realizes larger negative tolerance, completes the first few reduction excessively, the iron shape is small, and the transmission is fully dissatisfied. There are two reasons why inferior steel pipe has no metallic luster, light red or similar pig iron color. It is a blank adobe. Rolling temperature is not standard, they are the temperature of steel visually, so they can not be rolled according to the requirements of austenite region, and the natural properties of steel can not be achieved.