I. storage of welding rod
1, all kinds of welding rods must be classified, brand storage, avoid confusion, at the same time should be stored in a dry, well-ventilated warehouse, and placed from the ground and walls of no less than 300mm, to prevent damp deterioration.
2, as the coating is prone to moisture, moisture after the welding rod technology performance becomes bad, and hydrogen in the water is easy to cause weld pores and cracks, so the welding rod must be dried before use, in order to reduce the hydrogen content of the electrode, generally use 350 ~ 450 °, heat preservation for 1 ~ 2 hours, drying.
1, after the workpiece is combined, the first point welding is firm, start welding, the width-depth ratio of the weld is 2 ~ 3, the width of the weld is generally 1.5 ~ 2 times.The initial welding seam refers to the part that is just started to be welded. The arc should be slightly elongated after arc initiation, necessary preheating should be carried out on the end of the welding seam, and the arc length should be appropriately shortened for normal welding.
2. Weld finish means that when a weld is finished, the arc pit at the end should be filled. If the arc is immediately pulled off during the end, the arc pit lower than the surface of the welding parts will be formed, and too deep will weaken the strength of the weld finish, resulting in cracks.Therefore, arc pits are not allowed to exist in the end, so the arc pits should be filled up.
3, joint due to the limited by the length of the electrode, sometimes cannot finish a weld with a rod, called slightly lower, at the beginning of the welding joint was slightly before the beginning of the first weld arc, and slightly stretched arc arc toward the beginning to the end, and cover before the end of the weld, to start again after the weld seam welding flat along the welding direction.
4, the weld width of the general use of zigzag or crescent shape stripe method, this method of welding weld to strengthen the high height, good metal melting, has a long insulation time, easy to make gas precipitation and slag floating to the surface, to improve the quality of the weld.
The first layer of welding thickness and other layers of welding
Electrode diameter welding current (A)
≥6, 4, 160 ~ 210
When welding the second layer, the first layer of slag is removed, and then welding with larger diameter electrode and larger welding current.In order to ensure quality and prevent deformation, the welding direction between layers should be opposite, and the weld joints should stagger each other.