Renault 02-03-006C Metallurgical Verification File for Sintered Steel Parts

The purpose of the “Renault 02-03-006C Metallurgical Verification File for Sintered Steel Parts” standard, developed by the French automobile company Renault, is to define the metallurgical verification file for sintered steel parts (rough, semi-finished or finished) delivered to Renault and subject to the metal specification data sheet. The relevant parts list is in the Renault 01-00-510 standard (technical drawing, electronic signature of the part drawing by the materials engineering department).

The metallurgical verification file is part of Renault's supplier quality assurance approach. Its main purpose is to define the entire inspection process for the conformity of sintered steel parts.

To guarantee compliance with Renault or supplier requirements, the delivered product (part or assembly) must submit all metallurgical characterizations performed on it. These are documented by the first-tier supplier.

In the case of manufacturing or resource transfer, the first-tier supplier must provide a comparative file between new and old parts. This standard may also be applied to prototype parts where necessary.

The results for the metallurgical verification file should come from the following three points:

• The supplier laboratory is accredited by Renault's materials engineering department according to RPIF MESUR20160008 and NF EN ISO/IEC 17025 standards for the test method and the type of material being evaluated.
• The supplier laboratory in the European and American regions is accredited by a national organization for the test method and the type of material being evaluated.
• If the supplier laboratory lacks internal accreditations or approvals, reliance must be placed on external laboratories that address both the first and second cases. For other geographic regions, the materials engineering department must provide prior approval regarding laboratory selection.

To facilitate the creation of the metallurgical verification file, an example framework is provided that lists all the necessary information in this standard. A computerized version of the metallurgical verification file framework is available to the supplier upon request from the materials engineering department. However, the supplier is free to choose its own layout depending on the comprehensiveness of the information provided and the commitment to compliance.

This file should be provided as part of metallurgical verification for a new part reference, a product or process modification, a new foundry production facility, or a production transfer (welding) in the case of initial samples. The process trial must be consistent and precise.

The metallurgical verification file must contain all of the following information:

• Document:
• Report number
• Issue date
• Renault initiated the request (name, department)
• Presentation purpose
• RNES-B-00117 Sintered Material and Test Method (Unindexed)
• Piece:
• Part description
• Part reference
• Renault drawings index
• Supplier drawings directory
• Renault project (parts, vehicles, etc.)
• Security symbol if required.
• Thermal or thermochemical process
• Material description
• Material standard (Renault, European and international)
• Supplier or Renault technical specifications and requirements
• Production batch date
• Production batch number
• Suppliers:
• Ordinary
• Production and laboratory facility
• Processing plants
• Renault accredited laboratory
• If so, the date and number of the verification note.
• Otherwise, the name of the accredited laboratory that performed the tests, and the date and number of the accreditation.

Analyses or tests should be performed on samples taken from the parts. For a production batch of 1000 parts, suppliers should take 2 parts at the beginning, middle, and end of the production batch. Part traceability should be done with the following markings:

Private information includes the following:

• Part weight: The average is calculated based on at least 8 parts. The averages, minimum and maximum values ​​are entered into a results panel.
• Chemical composition: The chemical composition of the part must conform to the RNES-B-00117 sintered steel part standard. The requirements for the range of additional element content are specified in various standards referenced in the drawing and must be listed in that standard. If the range of additional element chemical composition differs from the standard, this discrepancy must be clearly stated in that standard.

Procedure: Carbon and other elemental contents can be determined by chemical analysis or X-ray fluorescence. The inspection report should specify the tests and methods used. Sampling requirements are not mandatory for each method.

• Density: Density, formulated in g/cm³, is determined according to the method described in the NF EN ISO2738 standard or an equivalent standard. Total density can be determined for the entire part or for 1/2 or 1/4 of the part. The density, along with the measurement technique, must be stated in the inspection report. The density uncertainty should be equal to or less than 0,05 g/cm³.
• Hardness: The chemical composition of the part must be suitable for the sintered material and the RNES-B-00117 test method. Hardness measurements (at least 5 points) are performed and determined according to the method described in the NF EN ISO 4498 standard or equivalent. The inspection report must state the arithmetic mean of the 5 valid determinations, rounded to the nearest whole number. The measurement point location and the reference measurement standard must be indicated.
• Grain structure: Micrographic samples should represent the different structures encountered in the part (sintering, quenching, tempering, heat treatment, thermochemical treatment, steam treatment, post-coating). They should also include the radius of mixing at the level of section change of the part. Pores are examined at 100x magnification without acid treatment, and the metallurgical structure is examined at 500x magnification after acid treatment with 2% or 4% diluted Nital. Each observation should be subjected to a close-up negative. These close-up negatives can be used to detect potential shifts during mass production of the part.
• Internal integrity compliance: No carburization, no crack-type defects, pore alignment, cohesion loss, overlaps.
• Tensile strength: 1/2, 2/2 and 3/2 parts are tested according to the test procedure specified by the supplier. This test is defined during the part file development phase. The results should include:
• Part references
• Type of test performed
• Test procedure reference
• Test machine type and reference
• Operator
• Date
• Values ​​to be measured (load at breaking, displacement at breaking, maximum load, etc.)
• Results obtained with measurement accuracy
• Test result

To facilitate understanding and prevent misunderstandings when presenting results, it is mandatory to provide the following information for each type of control:

• The normative documents and specifications required in the drawing approved by Renault's materials engineering department.
• Measurement locations along with the drawing of the part.
• Examination dates
• Laboratory areas
• Equipment used
• Compliance result based on specifications

On the other hand, all submitted documents must be legible (particular attention is paid to the quality of scanned documents). Micrographic and macrographic examination results should be combined with usable photographs.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "Renault 02-03-006C Metallurgical verification file for sintered steel parts" standard.