The beginning of welding practice will begin with the first arc. Arcing is the distance between the tip of the welding wire and the work metal surface, which is the perfect distance to allow the arc to continue. There are two methods of arc initiation. and how to knock
The scratching method is forcing the wire to come into contact with the work metal by scratching the side until an arc is formed, and then slightly lifting the wire up until the desired arc distance is approximately 1/8 inch. Knocking method is forcing the wire to be inserted vertically until it touches the work metal and then lifts it up and down. until an arc occurs as required
Note : Read more about welding knowledge and find more welding equipments at : https://www.udo.co.th/
Location of electric welding port
In electric welding, there are various types of welding ports as follows.
- The connection is stranded in a flat position. The flat landing connection is a type of seam that is most commonly used in Industrial works in various fields that are classified as economical joints. Don’t waste time preparing for work. There will be Maximum strength when welded joints on both sides In welding must not use too high current. angle of welding wire While welding about 45 – 60 degrees, the wire movement will be forward and backward along the weld line. This movement of the wire will preheat the work metal before it reaches the weld, which will complete the bulge of the weld. and prevent molten slag from flowing ahead of the weld.
- Connecting the seam butt flat Flat butt joints are the most common joints used for general-purpose metal joining. Metal works over ¼ inch thick, when welding seams on both sides, is a very effective seam. The weld strength is more or less depending on the size of the penetration depth of the weld. The depth of penetration depends on the size of the wire and the current used for welding. For applications with a thickness of 3/16 in. when only one side is welded. The seams are always spaced. But welding seams, flat positions must adjust the current. suitable for welding wire While welding, the wire must be tilted forward 10 – 20 degrees in the direction of the wire moving.
- Connecting a T-shaped joint in a flat position T-shaped butt welding must adjust the current to high enough to allow the molten metal to flow easily. To cause deep penetration to the bottom of the joint, forcing the welding wire to the corner of the joint. It must be pointed on the metal stand rather than the bed sheet. along with tilting the welding wire to Approximately 30 – 40 degrees ahead, try to move the welding wire at a steady speed. And there is a short-term forward backward in order to warm up the work at the bottom of the joint. It also prevents molten slag in advance of the weld.
- Welding in parallel position Welding of various joints in a horizontal position. Wire forcing. The welding wire must force the welding wire to point up at a 20 degree angle in order to apply force from the arc. help support the metal The molten pool flows down and flows back up to the weld. In addition, the wire must be tilted at an angle of 20 degrees in the direction of movement of the welding wire. as well as welding in a flat position
- Welding in the standing position This type of welding exercises can be divided into two methods: Up Hill and Down Hill. An important technique is to force the wire to be welded perpendicular to the surface Working metal and tilting the welding wire at an angle of upward pointing not more than 10 degrees. The current adjustment should always be adjusted to have a relatively high current. When welding, the welding wire should be moved as a lift. Then lower it down to the molten metal basin about 2 inches, but be careful not to let the arc extinguish.
To connect down, the current must be adjusted to increase. Tilt the welding wire at an angle pointing up about 15 – 20 degrees and force the wire to be perpendicular to the work surface. When welding, short arc distances should be used because the slag will normally melt ahead of the weld. when you see that slack Flow tries to shorten the arc distance. Along with increasing the speed more. If that doesn’t work, knock the slack off to clean. and start connecting
- Overhead welding position It is the most difficult welding position to perform. and causing the greatest danger to practitioners If the work clothes are not properly worn Important for overhead welding is adjusting the size of the current must keep high and use a short arc distance forcing the wire to be perpendicular to the work surface and make an inclination angle of not more than 10 degrees according to the direction of the wire moving. The movement of the wire will be forward and backward. or oscillating welding wire movement
- Types of welded joints Different types of weld joints can be distinguished on the basis of Preliminary welding joints for new trainees are as follows:
- Butt Joint
- Lap Joint
- Corner Joint
- T-joint type (T – Joint)
- Edge Joint
Electrical welding safety
In any welding operation, the operator must always consider safety in order to prevent accidents with yourself or others. These safety features include:
- Eye and face protection in order not to be harmed by ultraviolet rays and infrared radiation or sparks by wearing safety glasses and welding mask
- When welding, wear clothing made of refractory or inflammable materials.
- If clothes or pants have pockets, they must have a cover. The pants must not fold the legs.
- When working, wear leather gloves for connection.
- If you have no knowledge of electricity Do not connect electricity to the welding machine by yourself. should be released as the duty of the technician
- Do not expose any part of the body to radiation while welding.
- The operating room must be well ventilated. Prevent welding fumes
- Avoid operating in wet places as it may be electrocuted.
- When welding, the source of flammable substances must be taken into account. should stay away
- There should be a fire extinguisher in the welding area.