GB/T 37910.2-2019Non-destructive testing of welds -- Acceptance levels for radiographic testing -- Part 2: Aluminium and its alloys (English PDF)

Foreword

GB/T 37910, Non-destructive testing of welds - Acceptance levels for radiographic

testing, comprises the following two parts:

-- Part 1: Steel, nickel, titanium and their alloys;

-- Part 2: Aluminium and its alloys;

This Part is the 2nd part of GB/T 37910.

This Part was drafted in accordance with the rules given in GB/T 1.1-2009.

This Part was redrafted by modifying and adopting ISO 10675-2:2017, Non-destructive

testing of welds - Acceptance levels for radiographic testing - Part 2: Aluminium and

its alloy.

The significant technical changes and their reasons with respect to ISO 10675-2:2017

are as follows:

-- with respect to normative references, some adjustments are made in this Part

resulting in some technical differences, in order to adapt to the technical

conditions in China. The adjustments are intensively reflected in "Normative

references" of Clause 2. This Part:

 uses GB/T 3323.1 modifying and adopting the international standard to

replace ISO 17636-1 (see Clauses 1 and 3, and Annex A);

 uses GB/T 3323.2 modifying and adopting the international standard to

replace ISO 17636-2 (see Clauses 1 and 3, and Annex A);

 uses GB/T 32259 modifying and adopting the international standard to

replace ISO 17637 (see Clause 4);

 uses GB/T 6417.1 identically adopting the international standard to replace

ISO 6520-1 (see Clause 5, and Tables 2, 3 and A.1).

-- in accordance with ISO 10042, it adds the acceptance requirements that

uniformly distributed pores, clustered pores and linear pores shall meet gas

pores for the convenience of use (see 2b ~ 2e, 3 and 4 of Table 3);

-- in accordance with ISO 10042, it adds the acceptance requirements for oxide

inclusions and defines the requirements for the total length of imperfections

within the evaluation area for the convenience of use (see 6 of Table 3);

-- in accordance with ISO 10042, it adds the acceptance requirements for lack of

fusion and lack of penetration and defines the requirements for the length of a

single imperfection itself within the evaluation area for the convenience of use

Non-destructive testing of welds - Acceptance levels

for radiographic testing - Part 2: Aluminium and its

alloy

1 Scope

This Part specifies acceptance levels for indications from imperfections in aluminium

butt welds detected by radiographic testing. If agreed, the acceptance levels can be

applied to other types of welds or materials.

The acceptance levels can be related to welding standards, application standards,

specifications or codes. This Part assumes that the radiographic testing has been

carried out in accordance with GB/T 3323.1 or GB/T 3323.2. When assessing whether

a weld meets the requirements specified for a weld quality level, the sizes of

imperfections permitted by this Part are compared with the dimensions of indications

revealed by a radiograph made of the weld.

2 Normative references

The following referenced documents are indispensable for the application of this Part.

For dated references, only the edition dated applies to this Part. For undated

references, the latest edition of the referenced documents (including all amendments)

applies to this Part.

GB/T 3323.1, Non-destructive testing of welds - Radiographic testing - Part 1: X-

and gamma-ray techniques with film (GB/T 3323.1-2019, ISO 17636-1:2013, MOD)

GB/T 3323.2, Non-destructive testing of welds - Radiographic testing - Part 2: X-

and gamma-ray techniques with digital detectors (GB/T 3323.2-2019, ISO 17636-

2:2013, MOD)

GB/T 6417.1, Welding and allied processes - Classification of geometric

imperfections in metallic materials - Part 1: Fusion welding (GB/T 6417.1-2005,

ISO 6520-1:1998, IDT)

GB/T 32259, Non-destructive testing of welds - Visual testing of fusion-welded

joints (GB/T 32259-2015, ISO 17637:2003, MOD)

When quantification of undercut and/or excessive penetration by radiographic testing

is required, specific procedures using test exposures may be applied in order to

establish a basis for approximate quantification in accordance with the requirements

of ISO 10042. This shall be specified.

5 Acceptance levels

The acceptance levels for indications are shown in Table 3 and Table 4. The types of

imperfections are selected from ISO 10042 and defined in GB/T 6417.1. For the

numbers of imperfections see Annex A.

The symbols used in Table 3 and Table 4 are the following:

— A sum of projected areas of indications related to each L x Wp , in % (see Annex

B);

— b width of excess penetration of weld, in millimetres;

— d diameter of pore, in millimetres;

— dA diameter of pore envelope area, in millimeters;

— h width of indication, the width or height of surface imperfection, in millimetres;

— L any 100 mm testing length, in millimeters;

— l length of indication, in millimetres;

— s nominal butt weld thickness, in millimetres;

— t base material thickness, in millimetres;

— Wp width of the weld, in millimetres;

— suml summary length of imperfections within L, in millimetres.

If the interval between any two adjacent imperfections is less than the main dimension

of the smaller imperfection, they shall be deemed to be one imperfection. For the

calculation of accumulative areas of imperfections see Annex C.

Indications shall not be divided into different Ls.

Annex A

(Informative)

Guide to the limitations of radiographic testing

A.1 General

The numbers between brackets conform to those used in GB/T 6417.1.

A.2 Volumetric imperfections in butt welds

Volumetric imperfections in butt welds:

— Porosities (2011), clustered porosities (2013), elongated cavities (2015) and gas

pores (2017 )

—Elongated cavities (2015) and wormholes (2016)

— Oxide inclusions (303)

— Tungsten inclusions (3041)

The above imperfections listed in Table 3 will be readily detected using radiographic

technique A or B of GB/T 3323.1 or GB/T 3323.2 as shown in Tables 1 and 2.

A.3 Cracks in butt welds

Cracks in butt welds:

— Cracks (100)

— Crater cracks (104)

The detectability of cracks by radiographic testing depends on the crack height, the

ramification (presence of branching parts), opening width, direction of the X-ray beam

to crack orientation and radiographic technique parameters.

Reliable detection of all cracks is therefore limited. The use of radiographic technique

B or better, as specified in GB/T 3323.1 or GB/T 3323.2, will provide better crack

detectability than radiographic technique A.

A.4 Planar imperfections in butt welds

Planar imperfections in butt welds:

......