CTU in Prague

Faculty of Mechanical Engineering

Ing. Petr Vondrouš, PhD., IWE

Quality in welding

1st semester 2015/2016

Quality systems – welding

Quality system ISO 9000 – family of quality management systems

standards is designed to help organizations ensure that they meet the

needs of customers and other stakeholders while meeting statutory and

regulatory requirements related to a product.

Third-party certification bodies provide independent confirmation that

organizations meet the requirements of ISO 9001.

The ISO 9000 series are based on eight quality management principles.

8 Principles – Customer focus, Leadership, Involvement of people,

Process approach, System approach to management, Continual

improvement, Factual approach to decision making, Mutually beneficial

supplier relationships

Acc. ČSN EN ISO 9001:2001 7.5.2 welding qualifies as special process,

acc. to version 2008 it was renamed to processes requiring validation.

I.e. processes whose output cannot be verified before being released to the

customer = non-quality of execution is noted during usage of the product.

To conform with ISO 9001 these processes need to by validated, i.e.

confirmed through objective evidence that the requirements have been

met. “Validation shall demonstrate the ability of these processes to

achieve planned results.

These products and services require special attention during production to

ensure that they’re free of defects.

Special process are e.g. welding, shot blasting, painting, heat treatment,

mold making, sealing and many services, as restaurants, dentistry, hotels.

Based on ISO 9000 norm for welding qulity was designed ČSN EN ISO 3834.

Quality requirments for welding – ISO 3834

Welding quality cannot be inspected into a product, it has to be built in.

Even the most extensive and sophisticated NDT does not improve quality.

For products to be free from serious problems in production and in service,

it is necessary to provide controls, from the design phase, through material

selection, into manufacture and subsequent inspection.

ISO 3834 can be applied in the following circumstances:

• in contractual situations: specification of welding quality requirements;

• by manufacturers: establishment and maintenance of welding quality

requirements;

• by committees drafting manufacturing codes or application standards:

specification of welding quality requirements;

• by organizations assessing welding quality performance, e.g. third

parties, customers, or manufacturers.

ISO 3834 can be used by internal, external organizations, certification bodies, to

assess the ability to meet customer, regulatory or manufacturer's own

requirements.

Quality requirments for welding – ISO 3834

ČSN EN ISO 3834 – 1

Quality requirements for fusion welding of metallic materials - Part 1:

Criteria for the selection of the appropriate level of quality requirements

2 Comprehensive quality requirements

3 Standard quality requirements

4 Elementary quality requirements

5 Documents with which it is necessary to conform to claim conformity to

the quality requirements of ISO 3834-2, ISO 3834- 3 or ISO 3834-4

6 Guidelines on implementing ISO 3834

ISO 3834 is appropriate when demonstration of a manufacturer's capability

to produce welded constructions, fulfilling specified quality requirements in:

• a specification;

• a product standard;

• a regulatory requirement.

three levels specified to all

fusion welding processes

Selection of quality level

3 levels

2 Comprehensive quality requirements

3 Standard quality requirements

4 Elementary quality requirements

The manufacturer should select levels of quality requirements, based on

the following criteria :

⎯ the extent and significance of safety-critical products;

⎯ the complexity of manufacture;

⎯ the range of products manufactured;

⎯ the range of different materials used;

⎯ the extent to which metallurgical problems may occur;

⎯ the extent to which manufacturing imperfections, e.g. misalignment,

distortion or weld imperfection, affect product performance.

A manufacturer that demonstrates compliance to a particular quality level

is considered to have established compliance to all lower levels without

further demonstration.

ISO 3834-2 Comprehensive quality requirements

The manufacturer shall review the contractual requirements and any other

requirements, together with any technical data provided by the purchaser

or in-house data when the construction is designed by the manufacturer.

The manufacturer shall establish that all information necessary to carry out

the manufacturing operations is complete and available prior to the

commencement of the work. The manufacturer shall affirm its capability to

meet all requirements and shall ensure adequate planning of all quality-

related activities.

The review of requirements is carried out by the manufacturer to verify that

the work content is within its capability to perform, that sufficient resources

are available to achieve delivery schedules and that documentation is clear

and unambiguous.

ISO 3834-2 Comprehensive quality requirements

• Review of requirements

• Technical review

• Sub-contracting – possible, must comply all requirments

• Welding personnel - Welders and welding operators shall be qualified by an

appropriate test. Coordination personell.

• Inspection and testing personnel -The non-destructive testing personnel shall

be qualified. For visual testing test may not be required.

• Equipment – description, availability, suitability, maitanace

• Welding and related activities -production planning, The manufacturer shall

prepare the welding-procedure specification(s) and shall ensure that these are

used correctly in production. Work instructions

• Welding consumables - storage, control, batch testing

• Storage of parent materials – material must not be affected, identification

• Post-weld heat treatment –responsibility, compatibility, records

• Inspection and testing-before, during, after welding

• Non-conformance and corrective actions

• Calibration and validation of measuring, inspection and testing equipment

• Identification and traceability

• Quality records

Conclusion

To comply with ISO 3834 welding organization shall establish :

1) Defined criteria for review and approval of the processes

2) Approval of equipment and qualification of personnel

3) Use of specific methods and procedures

4) Requirements for records

5) Revalidation

Approval and qualification includes:

• Qualified personnel (welders, engineers, examiner)

• Qualified manufacturing processes

• Qualified equipment

This leads to qualification, training, testing norms

Levels of qualification of welders, operators

and welding personnel

Qualific

ation

level

Norms International

recognition

1 National norms

ČSN 050705

Welder

Operator

Certificate NO

2 EN 287

ISO 9606

EN 1418

Welder

Operator

Certificate,

Diploma

(ANB)

YES

3 ČSN EN ISO 14

731 Instructions

IIW, EWF

Higher

welding

personnel

Diploma

(ANB)

YES

Stages for welders qualification

TWI, 2010

• EN 287-1:2011 Qualification test of welders – Fusion welding,

Part 1: Steels

• EN ISO 9606-1 Steels

• EN ISO 9606-2 Al and its alloys

• EN ISO 9606-3 Cu and its alloys

• EN ISO 9606-4 Ni and its alloys

• EN ISO 9606-5 Ti and its alloys

• EN 287-6 Cast iron

• EN 14732 Welding operators for fully mechanized and automated

welding of metals

Qualification test of welders - Fusion welding

• EN ISO 9606-2 131 P FW 22 S t10 PB sl

131

P plate, Tube over d> 150 mm

FW fillet weld

22 Non precipitation hardenable alloys – 21, 22

S solid wire

t10 thickness 10 mm – t> 3 mm

PB PA, PB

sl single layer

Qualification acc. to ISO 9606 - Example

Approval, qualification of welding procedureEN ISO 15607 and 15609 define how welding process should be verifiedand gives details about the contents of a Welding Procedure Specification in the form of a list of information which should be recorded. This WPS isbasic document for verifying the welding.

Welding can be qualified by several ways:

1. Welds are done using only approved consumables and welding conditions recommended for welded material.

2. Weld that are approved by previous experience. Done accordingly to welds done in the past and successfully servicing now.

3. Approval by standard welding procedure. Applying welding procedure of other subject.

4. Running preproduction weld test.

5. Doing welding procedure test.

Welding procedure qualification

ČSN EN ISO 15607 Specification and qualification of welding procedures

for metallic materials - General rules

ISO 15609-1-6 - Specification and qualification of welding procedures for

metallic materials - Welding procedure specification – from arc, gas

welding upto laser hybrid welding

ISO 15610 Qualification based on tested welding consumables

ISO 15611 Qualification based on previous welding experience

ISO 15612 Qualification by adoption of a standard welding procedure

ISO 15613 Qualification based on pre-production welding test

ISO 15614-1-14 Specification and qualification of welding procedures for

metallic materials - Welding procedure test - from Arc and gas welding of

steels, Ni up to laser welding, resistence welding, cladding ….

1. EN ISO 15610 Approval By The Use Of Approved Consumables. An assumption can be made that a weld carried out using welding consumbles, approved by an inspection body, in accordance with the manufacturer’s recommended welding practices will produce welds suitable for simple fabrication work without the need for any formal testing. SIMPLEST but for limited range of conditiions and materials

2. EN ISO 15611 Approval By Previous Welding Experience. If the same system of welding has been used satisfactorily on welded fabrications for many years, it can be assumed that the welds thus produced are acceptable. Unfortunately we know from our knowledge of linear elastic fracture mechanics that a fine line often exists between a defective weld providing acceptable service life and one that causes a serious failure. Therefore this method should be used with caution.Documentation of production and tests need to be available.

3. EN ISO 15612 Approval By A Standard Welding Procedure. Fully documented procedures may be purchased, from reputable authorities, for joining materials that are relatively easy to weld such as plain carbon and austenitic steels. This route will be useful to companies which do not wish to get involved with qualifying their own procedures.for limited range of conditiions and materials

Approval, qualification of welding procedure

4. EN ISO 15613 Approval By A Pre-Production Welding Test. If a particular joint geometry cannot satisfy all the requirements of EN ISO 15614 Part 1 or Part 2 because of its size and testing requirements then a special test can be carried out representing the joint in all respects and subjected to as much of the testing required by EN ISO 15614 for a similar joint type.

5. EN ISO 15614-1- Welding Procedure Tests For The Arc Welding Of - Steel, Nickel and Nickel Alloys., Al…

It involves the welding of a test piece representing the production weld in all essential features. The completed test weld is then subjected to a variety of specific tests to ensure that the properties of the weld will be acceptable for most stringent applications.

• EN ISO 15614 Part 2 Arc Welding Of Aluminium and Its Alloys.

Approval by preproduction test

TWI, 2010

pWPS – Preliminary

Welding Procedure

Specification

WPQR – Welding Procedure

Qualification Record

(WPQR)

WPS – Welding Procedure

Specification

WPS qualification

Range of qualification

• Range of qualification is defined in norm

and works in simmilar way with EN 287-1.

• Cathegories

– Material

– Thickness

– Joint

– Pipe diameter

– Positions

– Filler

– Heat cycle

Step

diagram