Craftsman Shielded Metal Arc Welding flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Arc eye cause

Ultraviolet radiation from the welding arc inflames the cornea and conjunctiva, producing pain, tearing, and photophobia; symptoms often appear hours after exposure.

Metal fume fever

Welding zinc-coated steel can produce zinc oxide fume; inhalation causes flu-like symptoms such as fever, chills, nausea, and muscle aches, usually resolving within 24 to 48 hours.

Confined space oxygen range

Atmospheric testing for confined-space welding accepts oxygen from 19.5 to 23.5 percent by volume; outside this range, entry requires ventilation, isolation, and respiratory protection.

Hot work fire watch

A fire watch is required when welding sparks can ignite combustibles; NFPA 51B treats 35 feet as the typical spark travel distance, so combustibles within that radius must be protected or removed.

Heat input formula

Heat input in kilojoules per inch equals voltage times amperage times 60, divided by travel speed in inches per minute times 1000.

DCEP penetration

Direct current electrode positive places the electrode positive and is specified for many cellulosic and low-hydrogen SMAW electrodes; polarity affects penetration, deposition, and arc stability.

Arc length effect

Increasing arc length raises arc voltage, widens the bead, increases spatter and fume, and can cause undercut or porosity; a short arc concentrates heat.

Arc blow cause

Magnetic arc blow deflects the arc because of residual magnetism or current-path asymmetry; direct current is more susceptible, while alternating current and balanced grounding reduce it.

Duty cycle definition

Duty cycle is the percentage of a ten-minute period a power source can operate at rated output without overheating; a 60 percent rating allows six minutes of welding.

Constant current source

A SMAW power source has a drooping volt-ampere curve that holds current nearly constant as arc voltage changes, helping maintain stable melt-off as the operator varies arc length.

Open circuit voltage

Open-circuit voltage is the no-load potential between electrode holder and workpiece; it must be high enough to strike an arc but low enough to limit shock risk.

Carbon equivalent formula

Carbon equivalent equals carbon plus manganese divided by six plus chromium, molybdenum, and vanadium divided by five plus nickel and copper divided by fifteen; higher values increase cracking risk.

A36 steel properties

A36 is a low-carbon structural steel with a 36,000 psi minimum yield strength; it is readily weldable with SMAW when surfaces are clean and hydrogen is controlled.

Austenitic stainless 316

Type 316 stainless steel contains molybdenum, which improves chloride pitting resistance; welding requires low-carbon or stabilized grades and dedicated stainless tools to avoid contamination.

Aluminum oxide removal

Aluminum forms an oxide film that melts near 3,600 degrees Fahrenheit, far above the base metal; stainless brushes and appropriate cleaning remove it before welding.

Stainless wire brushing

Stainless steel must be cleaned with brushes and grinding wheels used only on stainless; carbon steel contamination can cause rusting and corrosion pitting in service.

Weld zone cleaning

Oil, grease, paint, rust, moisture, and mill scale within at least one inch of the joint should be removed because they can cause porosity, slag, and hydrogen cracking.

Five joint types

The five basic joint types are butt, lap, tee, corner, and edge; each describes how members are arranged rather than the weld type placed in the joint.

Root opening function

The root opening is the gap between members at the joint root; it allows electrode access and controls root penetration, but excessive gap can cause burn-through.

Tack weld requirement

Tack welds hold alignment during welding; they should be small, clean, and fully fused into the final weld, and cracked tacks must be removed before welding continues.

E7018 electrode meaning

In AWS A5.1, E7018 means a 70,000 psi minimum tensile strength, all-position electrode with a low-hydrogen iron-powder coating usable on AC or direct current electrode positive.

E6010 electrode meaning

E6010 is a 60,000 psi minimum tensile, all-position, high-cellulose sodium electrode designed primarily for direct current electrode positive, producing deep penetration and a forceful arc.

E7024 electrode use

E7024 is a high-iron-powder, titania-coated electrode limited mainly to flat and horizontal fillet welding; it provides high deposition but shallow penetration.

Low-hydrogen storage

E7018 and similar low-hydrogen electrodes must be kept dry in a holding oven at about 250 to 300 degrees Fahrenheit after opening; moisture pickup can cause hydrogen cracking.

Fillet work angle

For a 90-degree tee joint, the electrode work angle is normally 45 degrees, splitting the heat between both plates to produce equal fillet legs.

Vertical up technique

Vertical-up welding uses lower current and a slight weave so the molten pool freezes quickly; it gives better penetration and bead shape than vertical-down on thick material.

Root keyhole

A small keyhole at the leading edge of the root pass shows that the arc has penetrated through the root gap; losing it can indicate incomplete penetration or burn-through.

Slag removal reason

Slag must be removed between passes because trapped slag creates inclusions and prevents fusion; a chipping hammer followed by a wire brush is common for SMAW.

Dye penetrant testing

Penetrant testing detects surface-breaking discontinuities in nonporous materials; a penetrant enters flaws, is removed from the surface, and is drawn out by a developer.

Magnetic particle testing

Magnetic particle testing detects surface and near-surface discontinuities in ferromagnetic steel; magnetic flux leaks at flaws and attracts colored or fluorescent particles.

AWS reference line

The reference line in an AWS welding symbol carries the weld symbol and connects to the arrow line; its tail may list process, specification, or reference information.

WPS and PQR

A welding procedure specification gives required welding variables; it is supported by a procedure qualification record showing that a test weld met specified mechanical and inspection requirements.