7018 is a high-quality carbon steel electrode made of iron powder and low hydrogen potassium type coating. The welding rod has excellent welding process performance, good arc stiffness, not easy to produce magnetic bias, fine and clean shape of the weld, less spatter, and easy slag removal; the weld metal has excellent and stable low temperature toughness and crack resistance. Both AC and DC can be used for all-position welding.
70 refers to the minimum tensile strength (ksi) of the weld metal, and 18 refers to the position of the electrode, the type of coating, and the welding current.
Extended knowledge:
Welding methods are usually divided into three categories: fusion welding, pressure welding and brazing according to the heating and pressure conditions during welding:
1. Fusion welding is a method in which the metal at the joint of the weldment is heated to a molten state during the welding process, and the welding is generally completed without pressure. During fusion welding, the heat source quickly melts the metal at the weld joint and the filler metal added when necessary to form a molten pool. The molten pool extends with the movement of the heat source and forms a weld after cooling.
Fusion welding using electric energy can be divided into arc welding, electroslag welding, electron beam welding and laser welding according to different electric heating methods. Fusion welding has a wide range of applications, and is most commonly used in various welding methods, especially arc welding.
2. Pressure welding is a welding method in which weldments are joined together under pressure (heating or not). Generally, no filler metal is added during the pressure welding process. Pressure welding can be divided into resistance welding, high frequency welding, diffusion welding, friction welding, ultrasonic welding, etc. according to different welding mechanisms. Among them, resistance welding is the most widely used.
Most pressure welding methods do not have a melting process, and do not have the problems of burning of beneficial alloy elements and immersion of harmful elements into the weld like fusion welding. However, the welding conditions of pressure welding are harsh and the application area is narrow.
3. Brazing is a welding method in which a material with a lower melting point (soldering filler metal) is melted and then welded together, and the welded parts are connected together after cooling.