Non-uniform deformation of J55 casing pipe
hoop during metal pressure processing, the distribution of internal deformation and stress of the workpiece is not uniform, which affects both the quality performance of the product and the processing process. The main causes of deformation and stress unevenness are: external friction on the contact surface of the J55 casing pipe hoop, geometric factors in the deformation zone, non-uniformity along the degree of contraction, external end of the deformed object, uneven temperature in the deformed body, and deformation of the metal Nature and so on. Uneven distribution of deformation and stress causes unit deformation force, plasticity to decrease, and product quality to decrease. Then we have encountered how to solve it?
Measures to reduce distortion and uneven distribution of deformation: Correctly select the temperature-velocity system for deformation, minimize the harmful effects of external friction on the contact surface, and ensure the composition and organization of the deformed metal as even as possible. The fractures are different according to the plastic deformation before the fracture. The fractures can be divided into two types of brittle spear fractures. There are no obvious signs of plastic deformation in brittle fractures, and only a few traces of plastic deformation can be found near each fracture in each observation. The rupture and tensile stresses are close to orthogonal. The ductile fracture has undergone considerable plastic deformation before fracture. The main manifestation is the transgranular fracture. The intergranular fracture can only be seen when the high temperature is creeping. The main factors determining the metal fracture are deformation temperature, stress state and material nature. Cooling rate and temperature in the cooling intensity, strip thickness, mill speed, thermal properties, and cooling control temperature decrease greatly, laminar cooling area should be designed long enough, so that the letter can be achieved through a certain cooling rate to achieve the target Coiling temperature. There is a large transmission delay between the thermometer of the J55 casing pipe hoop and the thermometer in front of the coiler.