Campbell Hausfeld WF2054 Glossary of Welding Terms, Instrucciones para soldar Continuación

LIMPIEZA DE ESCORIAS

! ADVERTENCIA Use ante-

ojos de seguridad aprobados por la asociación norteamericana ANSI (ANSI Standard

Z87.1) (o alguna organización similar en sus respectivos paises) y ropa de protección para sacar la escoria. Los residuos calientes le podrían ocasionar heridas a las personas que se encuentren en el área de trabajo.

Una vez que haya terminado de soldar, espere a que las piezas soldadas se enfríen. Una capa protectora que llamaremos escoria cubre el reborde para evitar que los contaminanates en el aire reacionen con el metal derretido. Cuando el metal se haya enfriado un poco y no esté al rojo vivo, podrá limpiar el escoria. Esto lo puede hacer con una rebabadora. Golpee suavemente la escoria con el martillo hasta que logre despegarla. Finalmen-te, use un cepillo de alambre para ter-minar de limpiar.

POSICIONES PARA SOLDAR Básicamente hay 4 posiciones para soldar: plana, horizontal, vertical y por encima de la cabeza. Soldar en la posición plana es lo más fácil ya que la velocidad se puede aumentar, el metal derretido se chorrea menos, se puede lograr una mayor penetración y el trabajador se cansa menos. Para soldar en esta posición se usan angulos de desplazamiento y de trabajo de 45º.

Otras posiciones requieren técnicas diferentes tales como paso entretejido, circular o cruzado. Para completar este tipo de soldadura se requiere más experiencia en la materia.

Soldar por encima de la cabeza es la posición más dificil y peligrosa. La temperatura a usar y el tipo de electrodo dependen de la posición. Siempre debe tratar de soldar en la posición plana. Para aplicaciones especificas debe consultar un manual técnico.

PASOS

Algunas veces deberá usar más de un paso para soldar. Primero deberá hacer un paso primordial, éste será seguido por pasos adicionales de relleno (vea la Fig. 8). Si las piezas son gruesas, tal vez sea necesario biselar los bordes que están unidos en un angulo de 60º.

Recuerde que deberá limpiar las escorias antes de cada paso.

Operating Instructions and Parts Manual

Glossary of Welding Terms

Modelos WF2050, WF2054 y WF2057

Instrucciones para soldar (Continuación)

AC or Alternating Current - electric current that reverses direction periodically. Sixty cycle current travels in both directions sixty times per second.

Arc Length - the distance from the end of the electrode to the point where the arc makes contact with the work surface.

Base Metal - the material to be welded.

Butt Joint - a joint between two members aligned approximately in the same plane.

Crater - a pool, or pocket, that is formed as the arc comes in contact with the base metal.

DC or Direct Current - electric current which flows only in one direction. The polarity (+ or -) determines which direction the current is flowing.

DC Reverse Polarity - occurs when the electrode holder is connected to the positive pole of the welding machine. Reverse Polarity directs more heat into melting the electrode rather than the

Gas Metal Arc Welding (GMAW) - also called MIG, is a welding process used with a wire feed welding machine. The wire is solid and an inert gas is used for shielding.

Gas Tungsten Arc Welding (GTAW) - also called TIG, is a welding process used with welding equipment with a high frequency generator. The arc is created between a non-consumable tungsten electrode and the work piece. Filler metal may or may not be used.

Lap Joint - a joint between two overlapping members in parallel planes.

Open Circuit Voltage (OCV) - the voltage between the electrode and the work clamp of the welding machine when no current is flowing (not welding). The OCV determines how quickly the arc is struck.

Overlap - occurs when the amperage is set too low. In this instance, the molten metal falls from the electrode without actually fusing into the base metal.

Spatter - metal particles thrown from the weld which cool and harden on the work surface. Spatter can be minimized by using a spatter resistant spray on the work piece before welding.

Tack Weld - weld made to hold parts in proper alignment until final welds are made.

Travel Angle - the angle of the electrode in the line of welding. It varies from 5º to 45º depending on welding conditions.

T Joint - made by placing the edge of one piece of metal on the surface of the other piece at approximately a 90º angle.

Undercut - a condition that results when welding amperage is too high. The excessive amperage leaves a groove in the base metal along both sides of the bead which reduces the strength of the weld.

Weld Pool or Puddle - a volume of molten metal in a weld prior to its solidification as weld metal.

Cubierta

Relleno

Raíz

Figura 8 - Soldadura con filete (Ángulo de 60˚)

METODO USADO PARA SOLDAR

Según el tipo de material y el grosor de la pieza de trabajo deberá usar un método de desplazamiento de la pistola soldadora. Para soldar materiales delgados (de calibre 18 ó mayor) y cualquier pieza de aluminio, la pistola debe ubicarse al frente del sedimento y dirijirlo a lo largo de la pieza. Para soldar piezas de acero más gruesas, ubique la pistola directamente sobre el sedimento para aumentar la penetración. Este método se podría llamar de empuje (vea la Figura 10).

Figura 9 - Pasos múltiples

work piece. It is used on thinner material.

DC Straight Polarity - occurs when the electrode holder is connected to the negative pole of the welding machine. With straight polarity more heat is directed to the work piece for better penetration on thicker material.

Electrode - a coated metal wire having approximately the same composition as the material being welded.

Fillet Weld - approximately a triangle in cross-section, joining two surfaces at right angles to each other in a lap, T or corner joint.

Flux - a coating, when heated, that produces a shielding gas around the welding area. This gas protects the parent and filler metals from impurities in the air.

Flux Cored Arc Welding (FCAW) - also called Gasless, is a welding process used with a wire-feed welding machine. The weld wire is tubular with flux material contained inside for shielding.

Porosity - gas pockets, or cavities, formed during weld solidification. They weaken the weld.

Penetration - the depth into the work piece that has been heat effected by the arc during the welding process. A good weld achieves 100% penetration meaning that the entire thickness of the work piece has been heated and resolidified. The heat effected area should be easily seen on the opposite side of the weld.

Shielded Metal Arc Welding (SMAW)

-also called Stick, is a welding process that uses a consumable electrode to support the arc. Shielding is achieved by the melting of the flux coating on the electrode.

Slag - a layer of flux soot that protects the weld from oxides and other contaminants while the weld is solidifying (cooling). Slag should be removed after weld has cooled.

Weld Bead - a narrow layer or layers of metal deposited on the base metal as the electrode melts. Weld bead width is typically twice the diameter of the electrode.

Work Angle - the angle of the electrode from horizontal, measured at right angles to the line of welding.

HALE

EMPUJE

Figura 10

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