The electrode structural steel welding rod, heat-resistant steel electrodes, stainless steel electrodes, cast iron welding rod, copper and copper alloys, aluminum and aluminum alloys can be divided according to different uses. Welding rod slag chemical properties can be divided into: acidification electrode and alkalization electrode into two categories. Basic electrode welding weld containing hydrogen, sulfur, phosphorus. The weld good mechanical properties, but the oil, water, rust, sensitive, easy to produce pores. The acid electrode welding arc stability, low spatter, good slag removal. Therefore, the basic electrode welded structure selected, while the general structure of the pieces are chosen acid electrode. Structural steel electrode grades: Pinyin prefix plus a three-digit number to represent as our internship using grade structural steel electrode J422 (or junction 422). "J" word "knot" of the structural steel electrodes. Behind the two for the number "42" for the tensile strength of the weld metal is not less than 420MPa; last digit "2" stands for titanium calcium type coating, can be AC ​​or DC power. Acidic carbon steel electrode Category: J421 J421Fe J422, J423, J425, J502, J501Fe15 Grades GB model AWS model drug skin type current type uses specifications J421 E4313 E6013 dioxide type AC / DC welding low-carbon steel structures, especially suitable for thin small pieces and short welds smooth intermittent welding and surface requirements cover up welding Φ2.0-Φ5.0 Iron powder titanium AC / DC welding J421Fe E4313 E6013 generally low-carbon steel structures, especially suitable for thin small pieces and short welds smooth intermittent welding and surface requirements cover up welding Φ2.5-Φ5.0 J422 E4303 - titanium calcium type AC / DC the more important for welding of mild steel and low-alloy steel strength grade, such as 09Mn2 Φ2.0-Φ5.0 J423 E4301 - the ilmenite type of AC / DC weldable important low-carbon steel structure Φ3.0-Φ5.0 J425 E4311 E6011 cellulose potassium type AC / DC was applied to the sheet structure of butt, fillet and lap welding. Low-carbon steel structures such as power station flue duct, transformer tank, hull and vehicles outside board Φ3.2-Φ5.0 J502 E5003 - titanium calcium type AC / DC is mainly used for welding low alloy steel 16Mn Φ2.0-Φ5.0 J501Fe15 E5024 E7024 iron powder titania type AC / DC welding for rolling stock, shipbuilding, boiler structure Φ2.5-Φ5.0 Deposited metal chemical composition% weld metal mechanical properties Grade C Mn Si SP tensile strength (Mpa) Yield Strength (Mpa) Elongation (%) Impact value ℃ J J421 ≤ 0.12 0.3 ~ 0.6 ≤ 0.35 ≤ 0.035 ≤ 0.040 ≥ 420 ≥ 330 ≥ 22 0 ≥ 47 J421Fe ≤ 0.12 0.3 ~ 0.6 ≤ 0.35 ≤ 0.035 ≤ 0.040 ≥ 420 ≥ 330 ≥ 17 0 ≥ 47 J422 ≤ 0.12 0.3 ~ 0.6 ≤ 0.25 ≤ 0.035 ≤ 0.040 ≥ 420 ≥ 330 ≥ 22 -20 ≥ 47 J423 ≤ 0.20 0.3 ~ 0.6 ≤ 0.20 ≤ 0.035 ≤ 0.040 ≥ 420 ≥ 330 ≥ 22 0 ≥ 27 J425 ≤ 0.12 0.3 ~ 0.6 ≤ 0.30 ≤ 0.035 ≤ 0.040 ≥ 420 ≥ 330 ≥ 22 -30 ≥ 27 J502 ≤ 0.12 ≤ 1.60 ≤ 0.30 ≤ 0.035 ≤ 0.040 ≥ 420 ≥ 400 ≥ 20 0 ≥ 27 J501Fe15 ≤ 0.12 0.8 ~ 1.4 ≤ 0.90 ≤ 0.035 ≤ 0.040 Mo ≤ 0.30 V ≤ 0.08 ≥ 420 ≥ 400 ≥ 17 0 ≥ 27