Why do fillet welds need a multi-pass test?

Table 3.1.4.5a lists fillet welds only in the multi-pass column. A single-pass test gives a range for butt and T joints and does not list fillet welds.

Why does heat input change the result?

Above 50 kJ/cm the rules cover fewer steels, cap the approved thickness at the tested thickness, and add an impact notch position. Above 200 kJ/cm they add one more.

Why does the planner say to confirm some steels with the society?

For steels of lower strength, clause 3.1.4.3 (2) gives the strength range but says nothing about toughness. If the steel to be welded is a tougher grade than the test steel, the rule does not answer, so the planner does not either.

Engineering tool

Welding procedure qualification planner

Describe the butt weld test you plan to make. The planner shows the thickness range and steels the approval will cover, the tests and impact notch positions the test plate needs, and the values the results must reach, from the CCS Rules for welding procedure approval.

Test steelTest plate thickness (mm)JointWelding passesHeat inputWelding mode and positionDelivery condition of the test steel

Result

What the approval will cover

Thickness range for butt and T joints: 12.5 to 50 mm

Fillet welds are covered by the same range, applied to the thickness of both plates.

A multi-pass procedure cannot be used for single-pass welds (3.1.4.2).

A procedure approved on normalised, as rolled or controlled rolled steel generally covers TMCP steel too, but not the other way round (3.1.4.3 (5)).

Steels the procedure covers

A Covered
B Covered
D Covered
E Confirm with the society
AH32 Covered
DH32 Covered
EH32 Confirm with the society
FH32 Confirm with the society
AH36 Covered
DH36 Covered
EH36 Not covered
FH36 Not covered
AH40 Not covered
DH40 Not covered
EH40 Not covered
FH40 Not covered

Hover over a grade to see why.

Tests on the test plate (3.2.4.1)

Transverse tensile specimens: 2.
Transverse bend specimens: 4, two face and two root. From 12 mm thick, 4 side bend specimens may replace them.
Macro section: 1.
Hardness test: 1, taken with the macro section.
Longitudinal all-weld-metal tensile specimen: 1, only if the consumable is not yet approved.
Impact tests: sets of 3 specimens at these notch positions.

Surface side	a, b, c
Root side	a

a weld centre, b fusion line, c heat affected zone 2 mm from the fusion line, d 5 mm, e 10 mm.

Position d is added only when the approval will be used for important offshore structure joints (note 2).

What the results must show (3.2.5)

Joint tensile strength not less than 490 N/mm², the minimum for the base metal.
After bending, no opening defect longer than 3 mm in any direction on the tension surface.
Impact test temperature: 0 °C.
Average impact energy not less than 47 J.Manual or semi-automatic flat, horizontal and overhead welds: 47 J. Vertical welds and automatic welding: 34 J allowed.
Hardness not above HV350.
Macro section: good weld profile, full penetration, no cracks or lack of fusion.
Visual and non-destructive examination to ISO 5817 class B, with excess weld metal, convexity and root sag accepted to class C.

What this planner covers

CCS Rules for Materials and Welding 2021, Part 3 Chapter 3: the approved thickness range (Table 3.1.4.5a), the steels a test covers (3.1.4.3), the test specimens and impact notch positions (3.2.4.1), and the acceptance requirements (3.2.5): tensile, bend, impact temperature and energy, hardness and macro examination. It covers hull steels A, B, D, E and the AH, DH, EH and FH grades of 32, 36 and 40.

What it does not cover

Fillet weld throat ranges, pipe joints, welding positions and process-specific limits, welder qualification, aluminium and stainless steel, and test joints between two different steels (the rules take the impact specimens from the lower toughness side). It does not replace the approval, which is witnessed by your surveyor.

Questions about the approval range

Why do fillet welds need a multi-pass test?: Table 3.1.4.5a lists fillet welds only in the multi-pass column. A single-pass test gives a range for butt and T joints and does not list fillet welds.
Why does heat input change the result?: Above 50 kJ/cm the rules cover fewer steels, cap the approved thickness at the tested thickness, and add an impact notch position. Above 200 kJ/cm they add one more.
Why does the planner say to confirm some steels with the society?: For steels of lower strength, clause 3.1.4.3 (2) gives the strength range but says nothing about toughness. If the steel to be welded is a tougher grade than the test steel, the rule does not answer, so the planner does not either.

Source

Every table cell and clause above was read from the page images of the CCS Rules for Materials and Welding 2021. This is the CCS rule, not an IACS unified requirement: IACS UR W28 needs a free IACS login to download and was not checked. Your society's own rules govern.

This is a planning aid, not an approval. The approval certificate issued by your classification society states the approved range. For plate ready to ship, contact us. Request a quote