1, the larger the weld cooling rate, the intensity increased, the weld joints prone to crack under adverse circumstances, the choice of a lower strength than the base metal electrode level. Such as thick multi-layer welding or soldering treatment after normalizing the situation, you need to prevent the low intensity of the situation.
2, the same intensity level of acidity or alkaline welding rod selection. To the requirements of good plasticity, high toughness, low temperature performance, ability to use crack alkaline electrode. Such as the DC power supply difficulties, the choice of AC-DC dual-use alkaline Types Of Welding Electrodes.
3, for low carbon steel and low alloy steel, or between low-alloy and low alloy steel welded joints between dissimilar steels is generally used with a lower strength grade of steel box to adapt the welding material.
4, medium carbon steel welding. As the high carbon content in carbon steel, welding cracks tend to large, low hydrogen electrode can be used or weld metal with good ductility and toughness of the welding rod and welding pieces of gentle warm-cold treatment.
5, steel welding. High carbon content steel, thickness, shape complexity, easy to crack, especially the steel in the higher content of alloying elements. Choice of low hydrogen electrodes, and to take appropriate preheat and alloy process.
6, the workpiece, such as by preheating, welding current can be reduced when compared with no warm-up 5 to 15%; when using DC than AC can be reduced by 10%; Li Yang welding, soldering and welding than the horizontal by 10 to 15%.
7, the indoor welding, the need to pay attention to ventilation; outdoor welding, the operator should be on the outlet to reduce the inhalation of welding fumes.
8, with a grade of "B" (RH) and "Ni" of the Cast Iron Welding Wire, the hydrogen series ultra-low-high toughness electrodes, important structural parts for welding.