Parameters Of Steel Structure - Knowledge
The general sequence of welding is:pre-welding inspection→preheating and removing rust→installing welding backing plate and arc ignition plate→welding→inspection
1.Before welding,check the bevel angle,blunt edges,gaps,and the amount of misalignment.The rust spots,oil stains,and iron oxide scale in and on both sides of the bevel should be removed.
2.Warm up.Before welding,use gas welding or a special baking gun to evenly heat the base material within 100mm of the groove and both sides,and measure the temperature with a surface thermometer to prevent the temperature from not meeting the requirements or the surface local oxidation,and preheat the temperature.
3.Recheck the preheating temperature.if the temperature is not enough.reheat it to make it meet the requirements.
4.The surface cleanliness of the welding backing plate and arc ignition plate should be the same as that of the groove surface.The backing plate and the base material should be tightly attached,and the arc ignition plate and the base material should be welded firmly.
5.Welding:The first layer of weld bead should seal the connection between the base material and the backing plate in the groove,and then weld layer by layer until the groove is filled.After each weld is welded,the slag and spatter must be removed If welding defects occur,they should be ground and repaired in time.
6.An interface must be welded continuously.If it is necessary to stop welding in the middle,heat preservation and slow cooling should be carried out.Before re-welding,it should be heated again according to the regulations.
7.Welding should be stopped in rain or snow,and there should be windshield and rain awning around and above the welding joint of the component.Welding should be stopped when the wind speed is greater than 5m/s.When the ambient temperature is below zero,pre-heating and post-heating measures shall be adopted for construction.
8.Carbon steel structural parts should be cooled to ambient temperature after the weld,and low-alloy steel structural parts should undergo weld flaw detection 24 hours after completion.
9.Welders and inspectors should fill in the work record form carefully.