15MnVR steel welding points

15MnVR steel welding points:

7.1 , As Ajiutian power station using the thickness of the steel plate of the 15MnVRsteel minimum of 28mm , the warm-up measures for the plate thickness ≥ 32mm steel plate welded, preheating temperature of 150 ° C to -200 ° C.

7.2 welding layer between temperature <200 ° C, the welding energy 15KJ/cm - 55KJ/cm.

Automatic submerged arc welding H10Mn2 ф 5.0 of wire, DCRP welding current 700 - 750A, arc voltage 36 - 39V , welding speed of 22m / h .

7.3 welding process card

Welding process card see Appendix 1

Of 8 , 15MnVR steel welding requirements

Tack welding: tack welding and general welding after welding side groove, positioning must be cleared before the weld after the weld groove side welding, tack welding length should be 80mm , pitch 350mm .

2 welding groove group of quality, such as the size ultra poor or groove near defects put welding should be treated, you should check before.

3 welders to be in strict accordance with the 15MnVR steel welding process card welding.

4 welding inspector must be strictly in the welding process monitoring and control of preheating temperature, interpass temperature and welding line energy and actual welding specification parameters recorded on each weld.

5 non-arc, non-welded parts of the base metal on the temporary support of the test current and welding.

6 In addition to the weld outside, submerged arc welding and manual welding should be located arc plate (the introduction of the board and leads the board), size: submerged arc greater than or equal to 50 × 100 mm 2 , the hand arc may be appropriate to grasp.

7 double-sided welding seam, side of the weld, the other side can be used to the carbon arc gouging clear the root. Clear roots submerged arc welding must be cleared to the first seam completely exposed, the manual welding seam must be completely clear. Carbon arc gouging clear root to restrict the use of compressed air contains moisture and oil.

8 multi-layer multi-pass welding, every slag, spatter carefully clean, self-qualified to be the next one after welding. Weld surface is as smooth as possible, undercut, weld flash, excessive weld toe angle is too big sites use Spinning wheel carefully polished, so that the surface is smooth.

9 each weld number and write down the the welding welders name or code archive. Hit welders steel No. is prohibited. Tools and clamps removal of non-use hammering method, carbon arc gas gouging or gas cutting cut 3mm or more away from the wall outside, non-injury parent material, then polished smooth with a wheel and leakage testing and magnetic particle testing, due to the special reasons midway stop welding should be carried out immediately after the heat insulation, again should all be preheated welding the original welds requirements before welding.

9 , weldment orthopedic and after thermal stress relief

9.1 , the weldment orthopedic applications mechanical method, the shall heat orthopedic.

9.2 to eliminate welding stress using heated to 250 - 300 ° C after thermal insulation 1.2h - 1.8H , phased cooling method.

10 , the weld quality inspection

10.1 , weld, the first visual inspection. Visual inspection only after passing an internal quality check, internal the quality lossless checks weld finished 48h .

10.2 , weld appearance quality and internal quality check the press of GB3323 - 1987"steel melting welded butt joints radiography and quality grading" GB11345 - 1989steel welds manual ultrasonic flaw detection method and classification of testing results ", JB3965 - 1985 " regulatory requirements of the steel pressure vessel magnetic particle inspection ".

11 , patch

Manual welding or submerged arc if there is a problem we should be repaired, patches, note the following few:

11.1 , weldment surface arc, carbon arc gouging and other damage at must be polished with a grinding wheel, smooth over, then leak or magnetic particle inspection.Grinding depth of plate thickness more than 10% or greater than 2mm , welding repair.

11.2 , weld internal superscalar defects, surface crack repair before, you should analyze the reasons specified practical repair program.

11.3 preheat local weld repair should be carried out within the patch at around 15mmrange the preheating temperature control at 120 - 170 º C .

11.4 , weld defects can be used carbon arc gouging, grinding machine grinding method to clear, is not allowed in addition to planing with arc or gas flame melting, carbon arc gouging grinder and then clear clear carburized layer. Cleared of weld defects are not allowed burrs and dents, the bottom of the groove should smooth transition.

11.5 weld defect repair welding the same as the original weld, weld repairs to heat, post-heat temperature is the same as the original weld.

11.6 defect repair allows only once, the same position before the patch more than once should be approved by the person in charge of welding technology research.

11.7 , the quality requirements of the original weld repaired, check the method of repair at its near 100% check. Internal quality inspection should be completed 48hpatch .

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