Introduction
Friction stir welding, as a solid-phase jointing process, is increasingly used in aerospace, automotive, rail vehicles and other industrial fields. It has the advantages of no filler material, no melting of the material, low heat input, low welding distortion and high mechanical properties. The method is suitable for solid-phase welding of a wide range of materials and is currently the most mature and widely used in aluminium and aluminium alloys. Through the application of this technology has greatly improved the reliability and manufacturing accuracy of the components, has an important position, the development of aluminum and aluminum alloy stir friction spot welding general standards are of great significance.
GB/T 41979 "Stir friction spot welding of aluminium and aluminium alloys" is a standard for stir friction spot welding of aluminium and aluminium alloys. It is intended to consist of the following parts.
--Part 1: Terms and definitions. The purpose is to define the terms and definitions of friction stir welding.
--Part 2: Design of welded joints. The purpose is to standardise joint design criteria.
--Part 3: Assessment of welding operator's skills. The purpose is to establish common terms of use for the assessment of operator's skills.
--Part 4: Welding procedures and assessment. The purpose is to provide guidance on welding procedures and assessments.
--Part 5: Quality and Inspection Requirements. The purpose is to provide a technical basis for the production and inspection of stir friction blanching products.
This document, as a general standard for stir friction spot welding of aluminium and aluminium alloys, sets out the relevant skills assessment of welding operators and other aspects, thus facilitating the unification of stir friction spot welding on a national scale as a standard for skills assessment, as well as the principles and methods of skills assessment examinations, in order to facilitate the promotion and application of stir friction spot welding technology for aluminium and aluminium alloys in China's famous industries.
1 Scope
This document specifies the skill assessment requirements of the aluminum and aluminum alloy stir friction spot welding operators.
This document applies to the welding operators of stir friction spot welding of aluminium and aluminium alloys. This document does not apply to personnel specialising in the loading and unloading of automatic welding equipment.
2 Normative references
The content of the following documents constitutes the essential provisions of this document through the normative references in the text. Among them, note the date of the reference document, only the date of the corresponding version applies to this document; do not note the date of the reference document, its latest version (including all the revision of the list) applies to this document.
GB/T 3323.1 Radiographic inspection of welds Part 1, Film techniques for X and gamma radiation (GB/T 3323.1-2019, ISO 17636-1;2013,MOD)
GB/T 3323.2 Non-destructive testing of welds ﹑ Radiographic inspection ﹑ Part 2: X and gamma ray techniques using digital detectors (GB/T 3323.2-2019, ISO 17636-2:2013,MOD))
GB/T 3375 Welding terminology
GB/T 11345 Non-destructive testing of welds ﹑ Ultrasonic inspection grid techniques, inspection grades and assessment (GB/T 11345-2013,ISO 176402010,MOD)
GB/T 41979.1 Stir friction spot welding, aluminium and aluminium alloys Part I: Terminology and definitions (GB/T 41979.1-2022, ISO 18785-1;2018,MOD)
GB/T 41979.4
Stir friction spot welding of ﹑aluminium and aluminium alloys Part 4:Welding process procedures and assessment(GB/T41979.4-2022,ISO 18785-4:2018,MOD)
GB/T 41979.5 Stir friction spot welding of aluminium and aluminium alloys Part 5: Quality and inspection requirements (GB/T 41979.5-2022, ISO 18785-5;2018,MOD)
3 Terms and definitions
The terms and definitions defined in GB/T 41979.1, GB/T 3375 apply to this document.
4 Assessment requirements
4.1 General requirements
Welding operators should be trained in the operation of Friction Stir Welding equipment, including operational safety and items related to the parts to be welded.
Personnel who only perform loading and unloading operations do not need to have their skills assessed.
4.2 Assessment of welding operator skills
Welding operators shall be assessed by one of the following methods: a) standard welding test, see 4.4.1
b) welding process assessment test, see 4.4.2.
c) pre-production welding test or production welding test, see 4.4.3; d) product sampling welding test, see 4.4.4.
In addition, welding operators should pass a test on their knowledge of the operation of welding equipment, see Appendix A. The main parameters of the skill assessment and the scope of approval are described in 4.3 and their validity is described in Chapter 5.
4.3 Main parameters of skills assessment and scope of approval
4.3.1 General requirements
The skills assessment for welding operators is based on the main parameters (4.3.2 to 4.3.6). If the welding operator's work exceeds the approved range, a new skill assessment test should be carried out.
4.3.2 Friction stir welding methods
After passing the skills assessment for a particular stir friction spot welding method, the welding operator is only qualified to operate that method. Friction stir welding methods include the welding methods covered by GB/T 41979.1, as well as the welding methods specified in the pre-welding procedure (pWPS) or welding procedure (WPS) evaluated by YUKEN.
4.3.3 Welding equipment
A new skills assessment for welding operators is required when the following changes to the welding equipment occur and additional operator training is required:
a) When there is a change in the type (or mode) of welding equipment:
b) When control systems are added, removed or changed; X
c) when jigs, fixtures, feed units and other auxiliary equipment are added or removed from the welding equipment.
4.3.4 Base material
The Friction Stir Welding skill assessment test for any grade of aluminium and aluminium alloy is valid for all grades of aluminium and aluminium alloy. The Friction Stir Welding test for any base material thickness is valid for all thicknesses.
The Friction Stirring spot welding test for any base material form (including but not limited to plates, tubes, castings, forgings or stampings) is valid for all base material forms and tube diameters.
4.3.5 Joint shapes and sizes
The Friction Stir Welding assessment test for any joint shape and size is valid for all joint shapes and sizes.
4.3.6 Scope of approval of the skill assessment
The welding operator's skill assessment is valid to the extent that the following conditions are met:
-The valid welding procedure is followed;
-the type of welding equipment or spot welding method has not changed.
4.4 Method of assessment
5 Qualifications
5.1 General requirements
The certificate certifies that the welding operator has passed the skill assessment and that all the main parameters are recorded on the certificate and that no certificate should be issued if there are failures.
The certificate shall be issued by the examiner (or examination body) and the recommended certificate format shall be as shown in Appendix B. If other forms of certificate are used, they shall also contain the content required in Appendix B.
5.2 Validity
5.2.1 Initial effective date
The welding operator's certificate of competence is valid from the date of welding of the test piece, provided that he or she has passed the assessment of competence. The welding operator's qualification certificate is valid for 2 years and ends at the end of the month.
5.2.2 Validation
The manufacturer's welding manager (or the relevant manager) should confirm every 6 months that the welding operator is working within the scope of his certificate, otherwise, after the certificate has expired, the welding operator should have a new skills assessment before welding.
5.2.3 Extension of Certificate of Competence
A certificate may be extended indefinitely provided that the audit records from the date of validity of the certificate are complete and demonstrate that the holder has carried out welding work in accordance with the contents of the certificate within the previous 6 months.
Appendix A (informative) Operational knowledge of the functions of welding equipment
Appendix B (informative) Format for the certificate of qualification for Friction Stir Welding Operators
Forword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Assessment requirements
5 Qualifications
Appendix A (informative) Operational knowledge of the functions of welding equipment
Appendix B (informative) Format for the certificate of qualification for Friction Stir Welding Operators
