GB/T 29796-2013Laser repairing general specification (English PDF)

3.1 Remaining service life

The remaining service life, as referred to in this Standard, is the design life of a component minus the portion already consumed.

3.2 Rework

Rework, as referred to in this Standard, is an action taken on a nonconforming product to make it conform to the requirements. [GB/T 19000-2008, definition 3.6.7]

3.3 Repair

Repair, as referred to in this Standard, is an action taken on a nonconforming product to make it conform to the intended use. [GB/T 19000-2008, definition 3.6.9]

4.1 General requirements

4.1.1 Personnel, equipment, and environment a) Personnel shall be trained, qualified, and hold the appropriate certification before commencing work;

b) The used equipment shall be maintained and serviced in accordance with requirements;

c) The working environment shall meet the operational requirements of the equipment.

4.1.2 Relevant information regarding the components to be repaired shall be collected prior to laser repair

a) Operating conditions and use technical specifications for the component;

b) Design service life, duration of service, and history of operation under abnormal conditions of the component;

c) Maintenance records of the component;

d) Operating parameters such as working temperature, pressure, and working medium of the component;

e) Manufacturing drawings, material specifications, and details regarding heat treatment and surface treatment.

4.2 Technical assessment for component repair

4.2.1 Material analysis

a) Critical components. Verify material specifications if available; otherwise, conduct testing to determine the material;

b) Important components. Re-verification is optional if material specifications available; otherwise, conduct testing to determine the material;

c) General components. Subject to agreement between the client and the service provider.

4.2.2 Failure analysis

a) Critical components. A formal failure analysis report shall be provided;

b) Important components. Failure analysis shall be conducted;

c) General components. Subject to agreement between the client and the service provider.

4.2.3 Assessment of remaining service life

For components designed with a finite service life, an assessment of the remaining service life shall be conducted.

4.2.4 Calculation of strength

If the damaged area of the component affects safe operation; strength calculations shall be performed and a formal report provided.

4.2.5 Assessment of protective coating

For components with protective coatings, the condition of the coating shall be assessed.

4.3 Pre-repair inspection

4.3.1 Dimensional and geometric tolerance inspection

Measure and record the relevant dimensions and geometric tolerances of the component. If any abnormal deviations beyond tolerance limits are found, the client be reported for consultation and resolution.

4.3.2 Surface hardness test

Test and record the surface hardness of the area to be repaired or the adjacent zones. Any anomalies shall be reported to the client for consultation and resolution.

4.3.3 Non-destructive testing

The non-destructive testing shall be performed on the area to be repaired and adjacent zones of the component; the range of non-destructive testing for other zones shall be determined through consultation between the client and the service provider. Any anomalies shall be reported to the client for consultation and resolution.

4.4 Laser repair process design

4.4.1 Selection of laser cladding materials

Select cladding materials based on the composition and properties of the component material to be repaired, and ensure that the performance of the repaired component meets operational requirements.

4.4.2 Selection of laser equipment and process parameters

Select the laser equipment and process parameters based on the component's structural characteristics, operational requirements, and the properties of the cladding material, etc.

4.5 Laser cladding process qualification

4.5.1 Main inspection items for process qualification

a) Surface condition of the cladding layer. Visual inspection;

b) Mechanical properties. Conducted in accordance with GB/T 228 and GB/T 229 standards;

c) Metallographic structure. Conducted in accordance with the GB/T 226 standard;

d) Hardness. Conducted in accordance with the JB/T 6050 standard;

e) Non-destructive testing. Conducted in accordance with the GB 5616 standard.

4.5.2 Process qualification for special components

Determine through consultation between the client and the service provider based on operational requirements. […]

4.6 Quality inspection of repaired components

4.6.1 Dimensional test