WLD 150: Welding & Joining Final

___ coupled with riveting increases fatigue strength.

Adhesive bonding

___ occurs when the welder accidentally strikes the electrode on the base metal adjacent to the weld.

Arc strike

___ is a mechanical repair method in which a thinned, pitted, or cracked region of a part is ground away to create a gradual transition with the unaffected surface.

Blend grinding

___ is useful when weld repair is too difficult or unsafe, as in a storage tank that contains flammable vapors.

Blend grinding

___ requires that drillings be taken from the base metal and provides an accurate composition of the base metal.

Chemical analysis

___ magnetization is a concentric magnetic field produced by a straight conductor, such as a piece of wire, carrying an electrical current.

Circular

___ is appropriate for repairing metals that are difficult to weld, such as cast iron.

Cold mechanical repair

The process that converts an adhesive from the applied state to its final solid state is ___.

Curing

___ time is the elapsed time between the application of a developer and the examination of a part.

Developing

The application of a thin, hard, chrome coating to repair minor damage is ___.

Electroplating

___ reduces the fatigue strength of rotating or reciprocating equipment, such as shafts.

Electroplating

___ analysis provides a diagnosis of a technical cause of failure using experience gained from previous failures.

Failure modes and effects

A ferromagnetic material is a material that cannot be magnetized.

False

Cavities only occur on the surface of a weld.

False

Cure time is the total time a penetrant is in contact with a component surface.

False

Demagnetization is the ability of a material to retain a portion of an applied magnetic field after the magnetizing force has been removed.

False

GTAW is used for bronze bearing surfacing weld repair.

False

Gas tungsten arc welding (GTAW) is typically used for surfacing weld repairs on large components.

False

Larger diameter filler metal is preferred to reduce heat input for reducing distortion.

False

Nondestructive testing requires a part to be permanently removed from service.

False

Overlap need not be removed from a weld.

False

Porosity usually consists of long cavities parallel to the root of the weld.

False

Prods used for the prod method of magnetic particle examination must never be crisscrossed.

False

Root cracks are usually easy to detect.

False

Selective plating is the joining of parts with an adhesive placed between the faying (mating) surfaces.

False

Solvent cleaning includes sandblasting, sanding, and wire brushing.

False

The higher the load-bearing cross-sectional area, the higher the stress.

False

Throat cracks are cold cracks that are confined to the edges of a weld.

False

Welding is a mechanical repair method.

False

When performing the magnetic particle examination procedure, demagnetization is not necessary for engine and machine parts, as they typically contain residual magnetization resulting from normal operations.

False

___ is a series of parallel cracks approximately 1/2" apart that occur in brittle deposits as they undergo stress relief.

Linear fracture

___ repair does not involve a significant heat input.

Mechanical

___ crack when exposed to sulfur compounds, such as grease or oil.

Nickel alloys

___ analysis provides a diagnosis of the technical cause of failure using various analytical methods.

Physical failure

___ may be required after weld repair to restore mechanical properties.

Postheating

___ examination does not reveal very narrow discontinuities that are not closely aligned (parallel) to the weld, such as laminations.

Radiographic

___ examination uses X rays and gamma rays to detect discontinuities.

Radiographic

___ is a weld repair that applies surfacing to badly worn shafts by welding snug fitting, semi-circular forms to cover the shaft surface.

Sleeving

___ may be especially susceptible to lamellar tearing.

T-joints

A black light is used with the fluorescent liquid penetrant examination method.

True

A couplant is a liquid substance used between a search unit and a test surface to permit or improve the transmission of ultrasonic energy.

True

A satisfactory adhesive bond requires close contact between the surfaces to be joined.

True

A weld discontinuity is an interruption in the typical structure of a weld.

True

Certain repairs may require the approval of authorized personnel, use of a qualified procedure, and/or preparation of supporting documentation.

True

Cold mechanical repair is commonly used on metals such as gray iron, ductile iron, aluminum, bronze, steel, and fabricated steel sections.

True

Cracks are the most serious discontinuities in weldments.

True

Crater cracks are star-shaped cracks that extend from the crater of a weld to the edge of the weld.

True

Excess weld reinforcement establishes stress concentrations at the junction with the base metal.

True

Failure analysis provides an accurate explanation of the cause of a failure or loss of performance.

True

Hardness is a key indicator of mechanical properties for carbon and alloy steels.

True

Internal weld defects can be detected with radiographic testing equipment.

True

Most codes rely on ASME Section 1X and AWS D1.1 to describe the requirements for qualified welding procedures and welders.

True

Oxide inclusions occur when welding metals that have tenacious surface oxide films, such as stainless steels, aluminum alloys, and titanium alloys.

True

Oxyacetylene welding (OAW) and shielded metal arc welding (SMAW) are often preferred for field weld repairs.

True

Peening is performed prior to preheating the structure to be repaired.

True

Porosity consists of cavity-type discontinuities formed by gas entrapment during solidification.

True

Repair welding is used only if it is economical or if a replacement part is not available.

True

Slag inclusions can occur between passes or at the groove face.

True

The average stress on a weld is in direct proportion to the reduction of the load bearing cross-sectional area caused by a discontinuity.

True

The liquid penetrant examination method is used to find defects in a weld by outlining surface defects.

True

The primary causes of porosity are dirt, rust, and moisture on the surface of the base metal.

True

The weld piece must be magnetized when using the magnetic particle examination method.

True

Tungsten inclusions are particles from a nonconsumable tungsten electrode that enter the weld.

True

Underbead cracks are hydrogen cracks that occur in steels susceptible to hydrogen embrittlement during welding.

True

Undercut produces a stress concentration that reduces impact strength and fatigue resistance.

True

Visual examination is a form of nondestructive testing.

True

Wormholes can be prevented by using methods similar to those used to prevent porosity.

True

A(n) ___ uses a horizontal base line that indicates distance or time, and a vertical deflection from the base line that indicates relative amplitude of the returning signal.

a-scan presentation

A(n) ___ test consists of detecting acoustic signals produced by plastic deformation or crack formation during mechanical loading or thermal stressing of metals.

acoustic

A(n) ___ is a nonrelevant indication that appears on a radiograph.

artifact

Visual examination is used to ___.

check for surface condition

A ___ crack is a crack that develops after solidification is complete.

cold

The thickness of metal required to support a load on a part is the ___.

design thickness

A(n) ___ is a material that is applied to a test surface to accelerate bleedout and enhance the contrast of indications.

developer

The ___ examination method produces an eddy current in the test piece.

electromagnetic

A(n) ___ is a test piece that contains typical discontinuities that demonstrate that calibration equipment is detecting the discontinuities for which the part is being inspected.

equipment calibration standard

In ultrasonic welding, a ___ is one complete reflection of an ultrasonic beam.

full

A(n) ___ point is a point during a fabrication process where inspection and acceptance are required before fabrication can proceed.

hold

Crater cracks are ___ cracks formed by improperly ___ the welding arc in the crater of the weld.

hot; ending

In a(n) ___ test, closed containers are filled with water and a predetermined test pressure is applied.

hydrostatic

A(n) ___ is a device or combination of devices whose demonstrated image determines radiographic quality and sensitivity.

image quality indicator

Cracks are most commonly located by ___ testing.

liquid penetrant

The ___ examination method uses dyes to locate surface defects.

liquid penetrant

Throat cracks typically appear as relatively ___, ___ cracks along the centerline of the weld.

long; straight

Insufficient penetration caused by weld metal running ahead of the arc can be prevented by ___.

lowering the current

The ___ examination method uses a strong magnetizing current and a finely divided powder to detect defects.

magnetic particle

A ___ is a stress-concentrating condition caused by an abrupt change in section thickness or in continuity of a structure.

notch effect

In a(n) ___ test, air is pressurized in a closed vessel to reveal leaks.

pneumatic

Some ___ may be allowed by certain welding codes.

porosity

Porosity caused by excessive moisture on the joint surface can be prevented by ___.

preheating the base metal

A(n) ___ is a permanent, visible image on a recording medium produced by penetrating radiation passing through a material being tested.

radiograph

The ___ examination method uses photographic film or sensitized paper.

radiographic

A ___ wave is a transverse wave that represents wave motion in which the particle oscillation is perpendicular to the direction of wave propagation.

shear

A weld repair method that involves thin sheets of corrosion-resistant material welded to a corroded surface is ___.

sheet lining

A ___ joint contains insufficient adhesive to create an optimum bond.

starved

The ___ examination method uses high-frequency vibrations to locate defects.

ultrasonic

The ___ test is a nondestructive testing procedure.

ultrasonic

Crater cracks are most commonly detected by ___ examination.

visual