SSAW Blasting
Sources: this site Click: Date: 2015-8-9 18:40:19
When large diameter ssaw steel pipe blasting occurs because the weld being suffered stress and resultant stress is relatively small, blasting mouth is generally not originated spiral weld, its safety is higher than Longitudinal.
According submerged arc welding process delineated, and each shall have the arc welds and extinction at the office, but when each welded pipe girth weld, can not achieve this premise, whereby the extinction may have more at many welding defects. In an internal pressure of the tube, it is usually produced in two principal stresses in the wall, i.e., the radial stress and axial stress. Followed by pipe diameter increases, the steel grade of progress, the greater the ductile fracture occurred tip steady expansion trend. Withstand the maximum load because the radial stress is present in the maximum stress on large diameter spiral pipe, so the seam in a vertical stress that direction. Large diameter spiral welded steel pipe welds degree helix angle is generally, therefore spiral weld resultant stress is blasting Longitudinal principal stress test also shows the mouth of the ring spiral welded pipe bursting to the deformation rate was significantly greater than the Longitudinal.
From the welding process, the welding seam spiral welded steel pipes with straight consistent approach, but inevitably there will be many chances longitudinal welds of T, so there is also greatly improved welding defects, and weld seam at T residual stress is large, the weld metal are often in three-dimensional stress state, increasing the likelihood of occurrence of cracks. That is the biggest bear the load straight seam, circumferential welds to withstand a minimum load, spiral seam between.
When there are defects in parallel with large diameter spiral pipe seam around, because the smaller spiral weld force, so it is better to extend the risk of a large straight seam. It is evident that spiral welded plastic deformation capability than Longitudinal, blasting mouth generally confined to a pitch, which is the spiral weld to crack extension from a strong binding effect due.
According submerged arc welding process delineated, and each shall have the arc welds and extinction at the office, but when each welded pipe girth weld, can not achieve this premise, whereby the extinction may have more at many welding defects. In an internal pressure of the tube, it is usually produced in two principal stresses in the wall, i.e., the radial stress and axial stress. Followed by pipe diameter increases, the steel grade of progress, the greater the ductile fracture occurred tip steady expansion trend. Withstand the maximum load because the radial stress is present in the maximum stress on large diameter spiral pipe, so the seam in a vertical stress that direction. Large diameter spiral welded steel pipe welds degree helix angle is generally, therefore spiral weld resultant stress is blasting Longitudinal principal stress test also shows the mouth of the ring spiral welded pipe bursting to the deformation rate was significantly greater than the Longitudinal.
From the welding process, the welding seam spiral welded steel pipes with straight consistent approach, but inevitably there will be many chances longitudinal welds of T, so there is also greatly improved welding defects, and weld seam at T residual stress is large, the weld metal are often in three-dimensional stress state, increasing the likelihood of occurrence of cracks. That is the biggest bear the load straight seam, circumferential welds to withstand a minimum load, spiral seam between.
When there are defects in parallel with large diameter spiral pipe seam around, because the smaller spiral weld force, so it is better to extend the risk of a large straight seam. It is evident that spiral welded plastic deformation capability than Longitudinal, blasting mouth generally confined to a pitch, which is the spiral weld to crack extension from a strong binding effect due.
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