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QUALITY CONTROL PROCEDURE AND NORMATIVE FOR HIGHLY RELIABLE FLASH BUTT WELDING

Objective


The project can be considered reasonably successful. As mentioned earlier, the main objectives were achieved, some to as much as 90%, with others to a lower, although still highly significant, percentage.

The main contractors, Vicinay Cadenas and Seii, have both improved their positions in their specific markets, thanks to the performances achieved in the project.

The former because it has gained status as a leader on the world high-tech chain market, through having been the undisputed champion of new products such as:

- Studless chains and VGW chains.

- Development of UCL chains, a new, potentially revolutionary product which should be out on the market by 1999.

- Vicinay has also taken advantage of the technological and development know-how thrown up by the project to start parallel research projects, such as:

- Fatigue on real scale, with the Labein technology centre

- Queat, for the control and traceability of continuous heat treatments, run by Vicinay staff

- Quse, for computerisation and digital treatment of non-destructive, particularly ultrasound, test inspections.

As a consequence of the Qweld project, information from all these projects can be threaded and then linked to an individual component, thereby providing a history of all the significant events in the production cycle of the individual product in question, beginning with the raw materials and ending with the final part of the manufacturing process.
Flash Butt Welding (FBW) is the only technology accepted for the production of some high technology products with a very high requirements. That is the case of the chains used for sea platforms for petrol explorations. These chains, working 365 days/year, have a very high responsibility for human lifes and ecological damages. In fact, the historical breakings are accurately registered and assigned to each manufacturer. In this sense, it is essential for all manufacturers dependent on the FBW technology, to have a tight control of the process, which until now it has been posible because of the complexity of gathering and processing the big number of parameters affecting the process.

The main objective of this project is to develop a quality control system, based on statistic and empiric methods, that will be used for controlling the FBW soldering of high technologty chains. Furthermore, a pre-normative will be generated, that in a short period of time will generate regulatory standards and will be set as the state-of-the art practices all over the world. Additionally, the philosophy of the software and the computer system developed will be applicable to other complex processes. As a consequence of the establishing of the quality control system a parameter margin will be defined where the quality of the welding is guaranteed almost 100%. Furthermore:

- Providing a quality assurance level that not even 100% inspection attains.
- Inspection costs will be reduced from the present 16% to 6% of the total cost of manufacturing, because currently 100% inspection practices will be eliminated.
- Chain life will increase in 20%.
- Chain weight will be reduced in 15% for same requirements.
- Maximum load highter than 1.000 Mpa. Hopefully 1.200 Mpa, (currently, maximum load is 860 Mpa).
- The system will be able to work with 20 input process parameters, taking samples, and list them with 20 output parameters (types and levels of defects in the product).
- The system will be able to work in an industrial atmosphere, as this will be the testing environment.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

VICINAY CADENAS SA
Address
Particular De Sagarduy 5
48015 Deusto-bilbao
Spain

Participants (2)

DET NORSKE VERITAS IBERIA
Spain
Address
Alberio Alcocer, 46
Madrid
SEI SA
France
Address
Le Forum
64100 Bayonne