What are the common specifications of welding rods?

Common welding rods are mainly of the following types:

(1) For low-carbon steel structural parts, titanium calcium type E4303 (J422) or E5023 (J502) welding rods are generally used;

(2) For important structural parts that require high plasticity, toughness and crack resistance, low hydrogen type E4315 (J427) or E5015 (J507) welding rods are used. When using an AC welding machine for welding, AC/DC dual-purpose low hydrogen type E4316 (J426) or E5016 (J506) welding rods can be used.

(3) For thin plate components that require beautiful and smooth weld surfaces, it is best to use titanium type E4313 (J421) welding rods.

(4) For welding components that cannot effectively remove dirt such as oil rust and require a greater depth of penetration, it is best to use iron oxide type E4320 (J424) welding rods.

(5) For welded components with a large number of vertical welds, if conditions permit, special vertical downward welding electrodes, such as E4300 (J420) electrodes, can be used.

4. The above are common electrodes classified according to their uses. If classified according to the diameter of the electrode, the diameter of the electrode depends on the thickness of the weldment. The electrode is usually divided into 2, 2.5, 3.2, 4, 5, and 6 mm according to the size of its welding core. The most commonly used are 2.5, 3.2, and 4 mm. Their welding currents are 50-80A, 100-130A, and 160-200A, respectively.

5. In addition, the method of selecting the diameter of the electrode according to the thickness of the weldment:

(1) If the thickness of the weldment is ≤4 mm, the diameter of the electrode should not exceed the thickness of the weldment.

(2) If the thickness of the weldment is 4-12 mm, the diameter of the electrode should be 3-4 mm.

(3) If the thickness of the weldment is >12 mm, the diameter of the electrode should be ≥4 mm.

Take structural steel as an example: brand, compilation method. XXX, the third digit represents the type of coating, welding current requirements, the first and second digits represent the tensile strength of the weld metal.

J507—J represents structural steel welding rod

50 represents the tensile strength of the weld metal is not less than 490MPa

7 represents low hydrogen coating, direct current

The model of the welding rod is determined according to relevant national standards and international standards. Taking structural steel as an example, the model compilation method is the letter "E" represents the welding rod, the first and second digits represent the minimum tensile strength of the deposited metal, the third digit represents the welding position of the welding rod, and the third and fourth digits represent the type of welding current and coating type.