Control Measures of Spiral Pipe Laminar Imperfections

In the case of smelting tightly controlled, there may be layeredf for ssaw steel pipe defects, the control measures are following below:
1, To improve the toughness of plastic tube
Improve the cleanliness of molten steel and reduce harmful inclusions; increase the proportion of crystal axis slab, to reduce the center segregation and center porosity; the use of reasonable cooling system to avoid cracks appeared in the slab; slab or rolling off the assembly line to take the blank slow cooling process, reduce internal stress, thus ensuring the microstructure and mechanical properties of finished tube and pipe meet the technical standards.
2, The reasonable control of the heating temperature
By measuring the thermoplastic curve, choose the best heating temperature. Note also that there is enough heating tube holding time, in order to reduce and improve plastic deformation resistance and toughness.
3, Lower roll speed
Roll speed is a key parameter piercing process, the roll speed from low to high transition process, there began to appear a Layered critical roll speed. Lower roll speed, easy to form a tube bore; higher roll speed, and capillary tube formation of lamination defects easily. In order to eliminate the capillary tube and lamination defects, should reduce the roll speed to the start of the critical delamination roll speed or less.