How to control laminates defects in seamless pipes, there are some measures to take.
1, to improve the structure of the plastic pipe toughness
Improve the cleanliness of molten steel, to reduce harmful inclusions; increase the proportion of the slab crystal axis, to reduce the center segregation and center porosity; using reasonable cooling system to avoid cracks appeared in the interior slab; to be taken offline slab or billet rolling slow cooling process, reduce internal stress, thus ensuring the microstructure and mechanical properties of structural steel tube and finished to meet the technical standards.
2, the reasonable control of the heating temperature
By measuring thermoplastic curve, choose the best heating temperature. Also note that there is enough heating tube holding time, in order to reduce the deformation resistance and improve structural steel plasticity and toughness.
3, lower roll speed
Roll speed is a key parameter piercing process, roll speed changes from low to high in the process, there is a critical stratification began roll speed. Lower roll speed, easy to form a tube cavity; the higher roll speed, tube and pipe easy to form a hierarchical structure defects. In order to eliminate the structural steel tube and lamination defects, should be to reduce the roll speed began to appear layered below the critical speed of the roll.
Post time: Dec-09-2020