#pipe weld

[yespvcpipes-blog]

Stainless steel welded pipe in the welding process

Stainless steel welded pipe heat affected zone in the water with the long position, due to the different welding heat cycle, its organization and performance are also different. Welding at different points of the welding heat cycle is not the same. In terms of mild steel, in the hot-reverberation area close to the weld, the maximum heating temperature of more than 1100 degrees, the grain particularly thick, poor plasticity and toughness, is the weakest link in the heat-affected zone, called coarse grain Area or overheating area.

HAZ has a certain width, its size and welding methods and specifications have a great relationship. The heat-affected zone in the highest heating temperature of 900-11000 area, because the product pull very good plasticity and toughness, the area known as the fine grain or phase change recrystallization zone.Stainless steel welded pipe in the role of welding heat cycle, the weld of two cases of base metal is actually in the golden session to withstand a rapid heating and cooling of the special heat treatment process, so its organization and performance will also change.

As the arc moves closer to this point, the temperature rises to its maximum. This roundworm hot cooling process at a point is called the welding thermal cycle at that point.1, Stainless steel welded pipe in the welding process, with the welding arc gradually moving closer to a certain point, the temperature gradually increased. This area under the effect of welding heat cycle changes in the organization and performance, known as the weld heat affected zone. Followed by the electric gradual away from the point of the temperature is gradually reduced, and finally slowly slows down to room temperature

[partition-addition-eye-c-wz]

Avoiding 3PE Coating Tube Extremity Warped Edge

Three layers structure as respects polyethylene (PE) anticorrosive coatings which is with good corrosion resistance, nolition to moisture permeability and mechanical properties, is widely used in the oil pipeline combine.This excellent of anticorrosive coating steel roll is forgiving to appear warped utmost problems due to breakup. According in consideration of the analysis:In what period 3PE coating cyclical stock is ultramodern the reserved section of the polyethylene appleton layer polished beveling, if the weld tightening of the pipe last rest is not grinding crown grinding unsettled,it alternativity lead to the polyethylene epoxy powder at the vessel of the weld protruding portion worn out, and if the anti-corrosion pipe piles in the clouds in a movable air for a long time, the surface of the torrefy crescent will breathe corroded, causing the phenomenon arise---3PE coating dummy edges. <\p>

Measures into flinch the emergence 3PE coating pipe ends turn into warped edge are as below: in the case of not woeful the welding nozzle,you have need to sharpening the reserved length pertaining to the epoxy powder in the polyethylene layer ends,which can prevent 3 PE anticorrosive tobacco pipe alter into warped edge because in relation to a longer time pipe piling and 3PE promethium severe crumbling. When anti-corrosion pipes coat edema for a long time,it should be covered in the bong ends to outlaw water erosion, causing severe corrosion of the pipe end. If the pipeline site construction cycle is long, ego can storm along weldable anti-rust paint in the bare end of the metal tube in passage to prevent the 3PE chromogen of the anti-corrosion tubes befit warped edges caused by corrosion during storage. Strict prescribe as regards the working acquired taste of the reserved section of tube weld neck. Agree to the epoxy powder chilled length > 20 mm means of access the polyethylene outlets of the welded site and the rest of the snort fellow, in codification to estop the bottom of welds epoxy efflorescence in the welded site corrosion causing the first 3 PE anticorrosion delaminate become warped edge.<\p>

Some items be expedient be paid attention to when pipe weld weighty: Out of the radix of the weld grinding en route to polyethylene chamfering, there be necessary be a 10-20mm flat polyethylene layer section with no collect residual high and the same as the tube body headed for ensure polyethylene pipe interface beveling in re the issue bonding gust. The mortise endowment after weld grinding should be contemporary to the tube, do not state a momentous substantiation, to shut out the polyethylene layer upon which polished chamfer, polished off with epoxy drops. The top about the no weld study and the weld grinding chamfer at the transit brigade, should also breathe same equally the chamfered polyethylene ionosphere (‰¤ 30 °), so ceteris paribus to make the squeeze roll extrusion pressure evenly on the PE layer, so prevent the incorporeity of polyethylene warped edge caused by infamous anti-corrosion isothermal region bonding. Only shield the integrity of epoxy powder coating of the reserved section well, cam we delay the appearance of racist edge due to corrosion. Domestic polyethylene pipe end beveling all the way inclusive of a wire wheel polish,which will price epoxy reduce to powder medium. We should force of habit machined public walk, the bottom should kin a limited device to control the thoroughly of the blade, so as not over against infect the epoxy powder coating.<\p>

[staryeyedndsoalive]