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 deformation 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 universal standard is of great significance.
GB/T 41979 "Stir friction spot welding, 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 Friction Stir Welding products.
This document, as a general standard for stir friction spot welding of aluminium and aluminium alloys, sets out the relevant quality and inspection requirements and other aspects, which are conducive to the unification of product quality specifications and guidance for the implementation of the inspection tool Hugh, to enhance the quality of stir friction spot welding components, and to facilitate the promotion and application of stir friction spot welding technology for aluminium and aluminium alloys in various industries in China.
1 Scope
This document specifies the quality and inspection requirements for stir friction spot welding of aluminium and aluminium alloys. This document applies to the stir friction spot welding of aluminium and aluminium alloys.
2 Normative reference documents
The contents of the following documents constitute the essential provisions of this document through the normative references in the text. Where the references are dated, only the version corresponding to the date applies to this document; where the references are not dated, the latest version (including all amendment sheets) applies to this document.
GB/T 2654 Test method for hardness of welded joints (GB/T 2654-2008, ISO 9015-1:2001, IDT)
GB/T 3323.1 Non-destructive testing of welded joints ﹑ Radiographic inspection part 1, film techniques for X and gamma radiation (GB/T 3323.1 a 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 3323.2-2019,1SO 17636.2:2013,MOD)
GB/T 3375 Welding terminology
GB/T 9445 Non-destructive testing ﹑ Qualification and certification of personnel (GB/T 9445-2015,ISO 9712;2012,IDT)
GB/T 11345 Non-destructive testing of welds (ultrasonic testing, techniques, test grades and evaluation) (GB/T 11345-2013, ISO 17640:2010, MOD)
GB/T 18851.1 NDT penetrant testing Part 1: General provisions (GB/T 18851.1-2012, ISO 3452.1:2008, IDT)
GB/T 18851.5 Non-destructive testing Penetrant testing Part 5: Penetrant testing at temperatures above 50 °C (GB/T 18851.5 I-2014,ISO 3452.5:2008,MOD)
GB/T 18851.6
Nondestructive testing Penetrant testing Part 6: Penetrant testing at temperatures below 10 °C (GB/T 18851.6 I 2014, ISO 3452.6:2008, MOD)
GB/T 22087 Guide to grading the quality of arc-welded joints of aluminium and aluminium alloys for defects (GB/T 22087-2008,ISO 10042;2005,IDT)
GB/T 27552 Destructive testing of metallic material welds, microhardness testing of welded joints (GB/T 27552-2011, ISO 9015-2;2003,IDT)
GB/T 32080 Non-destructive testing, qualification of personnel for limited application of non-destructive testing (GB/T 32080-2015, ISO 20807;2004,MOD)
GB/T 32259 Visual inspection of fusion welded joints for non-destructive testing of welds (GB/T 32259-2015, ISO 17637; 2003, MOD)
GB/T 39081 Cross tension test method for resistance spot welds and projection welded joints(GB/T 39081-2020,ISO 14272:2016,MOD)
GB/T 39165 Test method for peeling and chiselling of resistance spot welds and convex welded joints (GB/T 39165-2020, ISO 10447;2015,MOD)
3 Terms and definitions
The terms and definitions defined in GB/T 41979.3,GB/T 3375 are applicable to this document.
4 Quality requirements
4.1 Welding personnel
The manufacturer shall provide appropriate welding personnel to plan, operate and supervise the production of Friction Stir Welding in accordance with the specified requirements. Welding operators shall be assessed in accordance with GB/T 41979.3 and the assessment records shall be kept up to date.
4.2 Testing and inspection personnel
4.2.1 General requirements
The manufacturer shall provide appropriate test and inspection personnel to plan, operate and supervise the test and inspection process in the production of Friction Stir Welding in accordance with the specified requirements.
4.2.2 Non-destructive testing personnel
NDT and visual inspection personnel shall be qualified in accordance with the requirements of GBT 9445 or GB/T 32080. If methods not included in the above standards are used for testing, the manufacturer shall be responsible for providing training, written procedures, tests and on-site demonstrations to ensure that the personnel are competent in the specified test methods, taking into account the requirements of the above standards.
4.2.3 Destructive testing personnel
Destructive test operators should be trained accordingly.
4.3 Equipment
4.3.1 Suitability of equipment
Welding equipment should be able to weld joints that meet the requirements.
Welding equipment should be regularly maintained and serviced and kept in good working order.
4.3.2 Equipment procurement
New or repaired equipment should be tested accordingly by the manufacturer/repairer and the user after installation to ensure that it works properly.
4.3.3 Equipment capacity confirmation test
Welding equipment shall be subjected to a capacity confirmation test to demonstrate that it is capable of repeatedly producing a satisfactory weld joint in accordance with the relevant requirements or design requirements if any of the following conditions occur:
--A malfunction that results in a change in the function of the equipment;
--repairs or maintenance that alter the function of the equipment.
4.4 Welding procedures
The manufacturer's responsible persons shall ensure that the welding procedure is correctly applied in production.
4.5 Stirring heads
4.5.1 Marking
Stirring heads used in production shall be permanently marked with a drawing number or part number etc.).
4.5.2 Inspection of the stirring head
Before welding, the stirring head should be clean and free from contaminants (e.g. oil, grease and dirt) that could adversely affect the welded joint. The shape of the stirrer head and its degree of wear should be checked periodically as required to ensure that it meets the requirements of the relevant design and process documentation and specifications.
The manufacturer shall determine the service life of the stirrer head, i.e. the maximum number of weld joints (which shall be recorded on the welding process specification).
4.6 Pre-weld preparation
4.6.1 Joint preparation
The joint surface should be prepared for welding in accordance with the welding procedure.
If sealants, adhesives or coatings are used, the composition and application requirements shall be specified in the welding procedure.
4.6.2 Pre-weld cleaning
Pre-weld cleaning shall be carried out in accordance with the welding procedure to remove oil, grease, dirt and other contaminants harmful to the quality of the welded joint from the surface of the base material.
4.7 Heat control
When required, the thermal control of the welded parts or equipment should be in accordance with the welding process.
4.8 Welding
Welding shall be carried out in accordance with the welding procedure.
4.9 Post-weld heat treatment
If post-weld heat treatment is required, it should be carried out in accordance with the post-weld heat treatment process specification.
Heat treatment process should be adapted to the base material, joint and weld type, and meet the product standards or requirements. The heat treatment process should be recorded and the records should be traceable.
4.10 Testing and inspection
4.10.1 General
The parts and number of tests and inspections depend on the product standard and the type of construction.
The test standards quoted below are not specific to Friction Stir Welding and may be applied by reference.
