API-577 Questions and Answers

Weldability

Toughness

Strength

Cooling rate

Steels that have a carbon equivalent below 0.30.

Cellulosic-type electrodes to reduce penetration.

Low-hydrogen consumables and electrodes.

Low-hydrogen root pass and cellulosic weld out.

Thickness of parent metal below alloy metal claddings.

Thickness of surface coatings or cladding thickness.

Extent of bonding of coatings or claddings.

Holidays in coatings or claddings.

Impact testing

There is no single test

Weld tension tests

Bend testing

Longitudinal groove

Incomplete fusion

Under fill

Undercut

6 in. (150 mm)

12 in. (300 mm)

24 in.(600 mm)

36 in. (900 mm)

Accept them if nonessential variable.

Reject them.

Re-qualify the WPS.

Accept them if the markings are corrected.

1.0

2.0

3.0

4.0

Chemical composition.

Strength of the electrode.

Coating characteristics.

Operating characteristics.

An area next to the heat-affected zone that has suffered some softening and loss of strength.

The microstructure of the weld that has been melted and will therefore have properties more like a casting than the base metal.

An area near the heat-affected zone affected by welding that may experience intergranular corrosion.

The high residual stress zone adjacent to the weld fusion line that will have higher hardness than the weld or base material.

Inadequate preheat

Improper welding speed

Improper heat input and improper welding technique

Not using a low hydrogen electrode or improper shielding

0.25 inch on either side of the fusion zone

0.25 inch away from the toe of the weld into the base metal

1 inch on either side of the centerline of the weld

Just adjacent to the toe of the weld

Chemical composition.

Electrode operating characteristics.

Welding position.

Coating operating characteristics.

A lighter density in the center of the width of the weld image, either extended along the weld or in isolated circular drops.

An irregular darker density near the center of the width of the weld image along the edge of the root pass image.

An abrupt density change across the width of the weld image with a straight longitudinal darker density line at the center of the width of the weld image along the edge of the density change.

A localized darker density with fuzzy edges in the center of the width of the weld image.

Use larger diameter electrodes.

Minimize weaving the bead.

Maximize weaving the bead.

Use high heat input.

Chemical composition.

Tensile strength to be higher than the base metal.

Acceptability of physical properties.

Need for postweld heat treatment (PWHT).

More susceptible to distortion during welding.

Less susceptible to cracking during welding.

More susceptible to brittle fracture.

Less susceptible to brittle fracture.

Welding process used and AWS classification numbers.

Welding process used and P-numbers of coupon welded.

P-numbers of coupon welded and AWS classification numbers.

Electrode-flux class and electrical characteristics.

Welding technique

Groove design

Base metal

Welding position

Joint design and test coupon thickness.

Base metal P-number and deposited metal thickness.

Type of welding process and test coupon thickness.

Electrode-flux class and electrical characteristics.

Neutralize and clean the surface within 6 in. (150 mm) of weld bevels

Steam out the piping system and dry

Verify with pH paper that any surface liquid is “basic"

Grind the surfaces near the bevel to remove contaminants

2 in. (5.1 cm)

3 in. (7.6 cm)

4 in. (10.2 cm)

6 in. (15.2 cm)

Arc drift.

Arc strike.

Arc blow.

Arc deflection.

Lamellar tearing

Hydrogen cracking

Sulfite stringers

Hot cracking

MT

UT

ET

RT

root opening.

root weld size.

groove weld size.

root face.

bevel face.

bevel angle.

groove angle.

groove face.

Equipment is simple, inexpensive, and portable.

The slag supports and shapes the weld bead.

There is a reduced requirement for ventilation.

There is minimal postweld cleanup.