Selection of electrode should consider the following principles: (1) According to the welded Welding Electrodes Manufacturers In China material select the appropriate type of category (categories). For example, the welding of carbon
Steel or ordinary low-alloy steel, structural steel welding rod should be used.
(2) performance of the weld and base metal properties to the same chemical composition or the type of weld and base metal of the same to ensure
Be the same.
Selection of structural steel welding rod, the first under the tensile strength of the base material by "and strong" intensity level relative to the principles of selection
With the structural steel welding rod. Secondly, the weld properties (ductility, toughness) demanding major structures, or easily
I cracks and structural steel (thickness, rigidity, low temperature welding) welding should be used in alkaline
Of the electrode, and even ultra-low hydrogen electrodes, high toughness electrodes.
With stainless steel electrodes and molybdenum and chromium-molybdenum steel, heat-resistant electrodes, the chemical composition should be based on the type of base material selected chemical
A welding electrode to the fiber under the skin composition characteristics of drug
1.1 cellulose electrodes drug skin contains a lot of cellulose (20% to 50%). The J422 is almost non-drug skin electrode cellulose component. 1.2 cellulose electrode has a strong anti-rust and anti-moisture, as long as the packaging well before welding generally do not need baking.
2 next to the welding electrode cellulose process performance characteristics
2.1 arc blowing force, penetration is good. Cellulose produced a large number of gas welding electrodes, so the arc and has a strong penetration of wind power. 2.2 arc of movement direction from top to bottom, easy to operate. 2.3 welding current large. The same diameter of the electrode, the use of welding current to the welding electrode than on the large 10% to 30% (Table 1).
Table 1 Comparison of welding current (unit: A)
Electrode diameter φ3.2 φ4.0 φ5.0
Next to the weld 80 ~ 140 100 ~ 170 140 ~ 220 Welded on to the 95 ~ 75 ~ 115 ~ 170 140 130
2.4 welding speed. Next to the weld root pass welding speed is off on the welding arc welding speed of 3 to 5 times the speed of the other bead is welded on the welding speed of 2 to 3 times.
2.5 weld multi-layered. Due to welding under welding speed, weld thickness compared to the weld on thin layers of the same weldment welded to the welding on the number of layers is about 1.5 times.
2.6 electrode diameter. Under the same wall thickness of the weldment to the welding electrode used to weld on the electrode diameter is 1.2 to 1.3 times the diameter (Table 2).
Name of the root bead welding heat welding the weld bead filled weld cap
Next to the welding electrode φ4.0 φ4.0 φ4.8 φ4.8
On the welding electrode φ3.2 φ3.2 φ4.0 φ4.0
2.7 welding line energy is small. Although under the same wall thickness steel pipe used in the welding electrode and welding current than the diameter of the weld increased significantly, but the welding speed increases more, so the welding heat input is smaller.
3 next to the weld bead cellulose quality characteristics
3.1 Forming Quality
(1) forming the root bead and back of the good.
(2) cap weld shape. Next to each weld bead thickness of 2 ~ 3mm, weld reinforcement is usually 0.5 ~ 2mm, forming beautiful.
Weld cellulose rod 3.2 internal quality (non-destructive testing quality)
(1) drug skin contains a lot of cellulose, a large amount of gas welding, can very well prevent the intrusion of air, wind ability.
(2) have a good process performance, the operation due to fewer defects.
(3) weld multi-layered, each layer thickness is small, fewer welding defects.
For these reasons, cellulose next to the weld has good internal quality, easy to check by nondestructive testing.
3.3 Mechanical properties of weld characteristics
As the cellulose electrode welding process next to the characteristics of weld small, with welding speed, welding heat input is small, the weld heat-affected zone also very small, so the weld and better mechanical properties of welded joints. We have done a number of technology assessment, fully able to meet the oil, gas and water supply and drainage pipe welding requirements.