SMAW Applications 311
SMAW Applications details the process of preparing SMAW equipment for welding and the basic steps a welder should take to perform a successful SMAW weld. Welders must be able to identify the different types of electrodes that can be used for SMAW and select the appropriate electrode for an application. A welder must then choose a method to start the arc and run a bead, and must know how to effectively break and re-start the arc when necessary. SMAW is not a perfect process, and this class covers the different flaws that a weld may contain as a result of different operator errors or other sources.
To be an experienced and skilled employee, a welder must know the basic foundational techniques of the welding process. SMAW Applications teaches welders the essential components of performing shielded metal arc welding processes, as well as how to identify and avoid common discontinuities.
Number of Lessons 20
- SMAW Overview
- Metals Welded with SMAW
- Joint Preparation
- Electrode Selection
- SMAW Basics Review
- Starting the Arc
- Starting the Arc In Action
- Electrode Orientation: Work Angle and Travel Angle
- Electrode Orientation: Techniques
- Travel Speed
- Running a Bead
- Breaking and Restarting the Arc
- SMAW Processes Review
- Amperage and Weld Quality
- Voltage and Weld Quality
- Common SMAW Problems: Porosity
- Common SMAW Problems: Undercut
- Common SMAW Problems: Incomplete and Excessive Penetration
- Common SMAW Problems: Incomplete Fusion
- SMAW Variables and Problems Review
- Describe SMAW.
- Describe the types of metals that can be welded with SMAW.
- Describe how to prepare to weld different types of joints with SMAW.
- Distinguish between the common types of electrodes.
- Describe the different methods used to start the arc in SMAW.
- Describe the angles that compose electrode orientation.
- Explain how to properly orient an electrode to yield a quality weld.
- Explain how to maintain the optimal travel speed for SMAW processes.
- Describe how to run a bead to yield a quality weld.
- Explain the concerns involved with breaking and restarting the arc.
- Describe the effects of amperage on weld quality.
- Describe the effects of voltage on weld quality.
- Describe porosity.
- Describe undercut.
- Identify incomplete and excessive penetration.
- Describe incomplete fusion.
A lightweight, highly conductive, silvery metal that resists corrosion and is a good conductor. Aluminum is a nonferrous metal.
American Welding Society
AWS. A professional organization that supports the welding industry. The AWS promotes welding and its related processes.
A measurement that indicates the amount of current flowing in a circuit, which is measured in amperes or amps. SMAW uses 10 to 500 amps.
The area in which electricity transfers from the electrode to the workpiece. The heat generated by the arc melts the base metals and filler metal during SMAW.
A condition resulting from the interaction of an electric current and the magnetic field that the current induces. Arc blow can cause excessive spatter, incomplete fusion, and porosity.
The distance the arc stretches from the electrode to the workpiece. Longer arc lengths require an increased level of voltage.
Moving the electrode along the workpiece opposite the direction of welding. The backhand technique is also known as the drag angle.
Metals that are welded together to form a joint. In SMAW, the welder guides the electrode along the seam of the base metals to make a weld.
An edge that is angled rather than perpendicular to the sides of the object. Beveled edges allow welders to access thicker base metals more easily.
A metal composed of iron, carbon, and silicon that offers heat resistance and compressive strength. Cast iron is a ferrous metal.
A tool used to scrape slag from a cooled weld bead. hipping hammers may also be called scaling hammers.
A weld that extends completely through the thickness of the base metals. Joints that require complete penetration may also require weld backing.
A material that allows electricity to flow easily. The components in the SMAW circuit must be effective conductors.
An electrode that conducts electricity to the arc but also melts into the weld as a filler metal. SMAW consumable electrodes also provide shielding that protects the arc and weld pool.
An undesirable depression in a weld bead. A crater can cause cracking if it is not properly filled.
The flow of electricity through a circuit. Current, also known as amperage, is measured in amperes, or amps, and controls the heat of the arc.
A material that removes oxygen from the molten weld pool and arc. Deoxidizers prevent oxygen from degrading a weld bead.
An irregularity in the specified and expected composition of a weld. A discontinuity is not always a defect.
An irregularity in the specified and expected composition of a weld. A discontinuity is not always a defect.
A weld made on a joint that is tilted on a downward angle. When welding downhill, gravity helps move the molten weld metal along, reducing weld time and base metal distortion.
Moving the electrode along the workpiece opposite the direction of welding. The drag angle is also known as the backhand technique.
A device in an electrical circuit that conducts electricity. In SMAW, the electrode also acts as filler metal.
An imaginary line that runs through the center of the length of an electrode. The electrode axis is perpendicular to and at the geometric center of its cross section.
The position in which a welder manipulates the electrode. Electrode orientation refers to the work angle and the travel angle.
A discontinuity that occurs when the weld metal melts through the base metal and exceeds the specified root reinforcement on the back side of a weld. Excessive penetration can be caused by too much heat, slow movement, or poor joint alignment.
An SMAW electrode that fills a joint quickly due to the addition of iron powder in the flux. Fast-fill electrodes are ideal for large workpieces.
An SMAW electrode that solidifies quickly. Fast-freeze electrodes are ideal for overhead welding and correcting poor fit-up and gaps.
A metal that contains iron. Ferrous metals are the most common type of welded materials.
A type of metal that has properties similar to those of the base metal and is added to the SMAW weld. Filler metal often adds to the strength and mass of the welded joint.
An SMAW electrode that has both fast-fill and fast-freeze characteristics. Fill-freeze electrodes both fill up a joint quickly and solidify quickly.
A welding position in which the welding is done from the upper side of the joint. In flat-position welding, the face of the weld is horizontal.
A non-metallic material used to protect the weld puddle and solid metal from atmospheric contamination in some welding processes. SMAW uses electrodes that have flux-coated cores.
Moving the electrode along the workpiece in the direction of welding. The forehand technique is also known as the push angle.
A type of weld that consists of an opening between two part surfaces, which provides space to contain weld metal. Groove welds are used on all joints except lap joints.
A mobile, handheld tool that uses an abrasive to wear materials away from a surface. Hand grinders can be used to remove heavy rust, scale, flash, primer, paint or other surface coatings.
A common welding position in which the weld is performed on the upper side of a horizontal surface and against a vertical surface. Horizontal-position welding used for fillet and groove welds.
Visible, small holes in the weld at the start or re-start that result from inadequate arc shielding due to improper starting techniques. Hydrogen entrapment is also known as hydrogen porosity.
A weld discontinuity in which fusion did not properly occur between the weld metal and base metal or adjoining weld beads. Incomplete fusion is caused by faulty operator technique, improper base metal preparation, insufficient welding heat, lack of access to adjoining beads, and improper joint design.
A discontinuity characterized by an unpenetrated and unfused area in a joint that occurs when weld metal does not extend through the thickness of the joint. Incomplete penetration can result from insufficient welding heat, improper joint design, and improper lateral control of the welding arc.
A variety of processes that prepare base metals before welding. Joint preparation may involve cutting, grinding, preheating, or other processing.
The edge of the weld pool that is most in front of the arc during a weld. The welder should always keep the arc on the leading edge of the weld pool.
A carbon steel that contains less than 0.30% carbon. Low-carbon steels are generally tough, ductile, and easily welded.
An SMAW electrode that is used to weld metals that can be susceptible to cracking. Low-hydrogen electrodes are ideal for awkward positions.
An arc welding process that uses a flux-coated rod at the center of its electrode. Manual welding is also referred to as shielded metal arc welding, SMAW, and stick welding.
multiple weld pass
A weld that is formed by two or more passes, one over the other. Multiple weld passes generally combine different types of weld beads.
A hard, malleable, silvery-white metal with high strength, toughness, and impact resistance. Nickel is a nonferrous metal.
A colorless, odorless, tasteless gas that naturally exists in the atmosphere. Nitrogen can degrade a weld bead.
A metal that does not contain iron as a main ingredient. Common nonferrous metals include aluminum, titanium, copper, and nickel.
Welds performed by a welder that are not made in a classified or categorized position. Out-of-position welds are often done with electrodes that have smaller diameters to prevent spillage.
Welding that is performed from the underside of a joint. Overhead-position welding requires extra safety precautions.
The protrusion of weld metal beyond the weld toe. Overlap creates a poor weld to base metal connection and can lead to premature weld failure.
A colorless, odorless, tasteless gas that naturally exists in the atmosphere. In welding, too much oxygen causes cracking and rusting in the metals.
An intersection of two lines or objects at right angles to one another. Perpendicular lines create angles measuring exactly 90 degrees.
A discontinuity characterized by the appearance of tiny voids or bubbles on a weld bead, resulting from trapped gases in a material. Excessive porosity can weaken a weld.
A discontinuity characterized by the appearance of tiny voids or bubbles on a weld bead, resulting in gas pockets. Excessive porosity can weaken a weld.
Moving the electrode along the workpiece in the direction of welding. The [push angle is also known as the forehand technique.
A scrap piece of base metal with the same groove as the workpiece. Run-off tabs are tacked onto the end of the workpiece to allow the welder to extinguish the arc without forming a crater on the workpiece.
A method of starting the arc in which the welder quickly guides the electrode across the workpiece at an angle. The scratching method is only one of the ways to start an arc.
shielded metal arc welding
SMAW. An arc welding process that uses a flux-coated electrode.
A gas or type of solid material that protects the weld pool and arc from atmospheric contamination. Shielding is provided by the material coating on the electrode in SMAW processes.
single weld pass
A weld that is formed using only one pass. Single weld passes are often done using stringer beads.
Cooled flux that forms on top of the weld bead. Slag protects cooling metal and is then chipped off.
A weld defect caused when flux residue is trapped between two layers of weld metal. Slag entrapment can negatively affect the strength of a welded joint.
Shielded metal arc welding. An arc welding process that uses a stick-shaped flux-coated electrode. SMAW is also referred to as stick welding and manual welding.
Liquid metal droplets expelled from the welding process. Spatter can leave undesirable dots of metal on a workpiece surface and lead to welder injury.
square butt joint
A type of weld that consists of an opening between two square part surfaces, which provides space to contain weld metal. In SMAW, a square butt joint requires the welder to square off the edges of base metals to effectively make the weld.
A metal consisting of iron and carbon, usually with small amounts of other elements. SMAW is often used to weld different types of steel.
A type of weld bead formed by moving the electrode straight across the joint. A good stringer bead looks like a roll of dimes.
A method of starting the arc in which the welder moves the electrode to the base metal in a vertical direction and withdraws it quickly. Tapping is only one method used to start an arc in SMAW.
A type of joint formed between two perpendicular metal parts, forming the shape of the letter "T." T-joints also have right angles and perpendicular lines.
The acute angle between the electrode axis and a line vertically perpendicular to the weld axis. The travel angle points the electrode either in toward or away from the direction of welding.
The speed at which the welder moves the electrode along the joint to make a weld. Travel speed determines the size of the weld bead.
An unintended gap left in a finished weld. Different amounts of undercut may be acceptable, depending on the welding code and application.
The welding position in which welding is done on a vertical surface, moving up or down. Vertical-position welding is more difficult than flat- or horizontal-position welding.
A measure of electrical pressure or potential. Voltage is measured in volts.
A weld bead formed by moving the electrode along the joint in a weaving motion. The second and subsequent passes of an SMAW bead use a weave bead.
An imaginary line through the center and along the length of a weld. The weld axis is located at the geometric center of its cross section and is horizontal with the workpiece's surface.
A material placed against the back side of a joint to support or retain the molten weld metal. Weld backing may remain fused and a permanent part of the weld or unfused and removed after welding.
The end product of a joint that has been welded. Beads are formed using a variety of different techniques.
The pool of molten metal that is created by the heat of the welding torch. An arc is struck between the weld pool and the electrode in SMAW.
The point at which the back of a weld intersects the surfaces of the base metal. Weld backing prevents molten weld metal from spilling out of the weld root.
The point at which the weld face and the base metal meet. Weld toes can experience cracking and undercut.
The ability of a material to be welded under imposed conditions into a specific, suitable structure and to perform satisfactorily for its intended use. A metal can have good, average, or poor weldability.
A term that is used to refer to the person who is welding. A welder uses a power source.
The position in which the welder performs a weld. The different welding positions include overhead, vertical, flat, and horizontal-position welding.
A technique typically used for forming a stringer bead that involves moving the electrode around in a circle and withdrawing it slightly, then repeating this technique to form a bead. The whip technique can only be used with fast-freeze electrodes.
A finishing tool with wire filaments used to remove dirt, light rust, and other loose materials. A wire brush may be used to clear the surfaces of base metals before a welding operation.
The angle less than 90° between a line perpendicular to the workpiece and a plane determined by the electrode axis and the weld axis. The work angle is used to center the weld bead on a given application.
The object or material being welded. Workpieces can be made out of a variety of materials when SMAW is used.