1, Welding Supplies the appearance of defects: the appearance of defects (surface defects) means without the aid of instruments, the defect can be found from the surface of the workpiece. The common cosmetic defects have undercut, weld flash, dents and welding deformation, and sometimes the surface porosity and surface cracks. The root of the single-sided welding incomplete penetration and so on.
2, porosity and slag
A stomatal pores welding, the gas in the molten pool did not escape before the solidification of the metal remaining in the hole formed in the weld. Gases may be melting slag slag welding refers to the phenomenon of slag remaining in the weld.
3, Mig Welding Rod the cracks in the weld atom bonded destroyed, generating a new interface is formed a gap called crack.
Lack of penetration is not penetration unmelted base metal, weld metal into joints roots.
5 unfused unfused unmelted combined defects in the weld metal and the base metal material, or between the weld metal. Its where the location, lack of fusion can be divided into the groove lack of fusion, lack of fusion root incomplete fusion of three layers.

Electrode welding core and coating by the two parts. Metal welding electrodes in the outer core of the coating ( coating ) uniform pressure applied to carefully solder core. Welding rodDifferent types, welding core is different. Welding electrode core metal core , as Guarantee the quality and performance of the weld , butt in the core content of the metal elements have strict rules, especially harmful impurities ( such as sulfur, phosphorustc. ) content, should be strictly limited, than the base metal . Welding core into Of a direct impact on the composition and properties of the weld metal , Stainless Steel Electrode so the welding core harmful elements as little as possible . Welding carbon steel and low alloy steel welding core , are generally used as a low-carbon steel core wire and fill plus manganese, silicon , chromium, nickel and other ingredients ( see wire StatesHome standard GB1300 -77 ) . For one, using a low-carbon containing Low carbon steel plastic, wire drawing is easier , on the other hand reduce the CO content in the reducing gas , reducing splashing or pores, andIncreased weld metalsolidification temperature favorable for overhead welding . Join itsHis main alloying elements in order to ensure the comprehensive mechanical properties of the weld , while the welding performance and remove impurities, also have a role . High alloy steel as well as aluminum , copper, iron and other metal materials, welded to the core component in addition to the metal to be welded with similar requirements , the same also control the impurityContent , according to process requirements often adding certain alloying elementsElectrode is coated with a drug skin used for SMAW consumable electrode , it is by coating and welding core composed of two parts . In front electrode coatingThere are about 45 ° chamfer , which is to facilitate the arc . In the taiA bare core wire , rod length of about 1/16 , to facilitate welding clamp holding and contribute to conductivity . Diameter of the wire Chung actually refers welding core diameter ) throughOften for 2,2 . 5,3 . 2 or 4, 5 or 6mm , such as several specifications, Used is a small 3.2 , four small , a small 5 three, the length "L" in general between 250 ^ -450 mm .