ELECTRON BEAM WELDING ON LARGE THICKNESS STEELS FOR HEAVY INDUSTRY

Información del proyecto

Identificador del acuerdo de subvención: RI1B0258

Proyecto cerrado

Fecha de inicio 1 Enero 1989

Fecha de finalización 30 Septiembre 1993

Financiado con arreglo a

• Multiannual research and development programme (EEC) in the fields of basic technological research and the applications of new technologies (BRITE), 1985-1988

Coste total

Sin datos

Aportación de la UE

Sin datos

Coordinado por

SOCIETE FRAMATOME
France

Objetivo

Major improvements in status of the art of electron beam (EB) welding on large thickness chromium molybdenum steels have been achieved.

Beam measurements experiments were performed with a computer controlled electron beam diagnosis system, eliminating the need for complex and cost intensive welding tests to determine the optimal focus adjustments at different machines. The improved analyser is now suitable for use under industrial conditions.

Using the diagnosis system, progress has been made on the equipments investigated in the project. It was shown that, particularly in case of welding heavy thickness components, focus position, aperture, diameter and the distribution of the power density of the beam strongly influence the quality of welds.

Demonstration of defect free welds both on 100 mm and 200 mm thick chromium molybdenum material was made. Evaluation proved sufficient values for the mechanical values after post weld heat treatment. EB welding of linear or cylindrical components up to 100 mm is considered practical, without strong risks concerning the mechanical and geometrical quality of the weld. EB welding of higher thickness is still considered to be a risky undertaking, because of low reproducibility of quality. Demonstration of feasibility of good fade outs has only been partially done. Parameters and welding conditions influencing the quality of fade outs have been determined.

By nondestructive examinations (NDE), most of the typical defects occurring with electron beam welding have been detected. The only defects still needing development of adapted NDE methods are cold shuts occurring at the bottom of partial penetration welds. Use of radiographs associated with ultrasonics is strongly recommended.

High homogeneity of mechanical characteristics was reached on 2.25 chromium molybdenum steel after quality treatment. EBW welding was able to meet the most severe specifications. As this ability was directly linked to the purity of base metal, it is particularly important to specify a very high level of cleanliness of base metal.

A personal computer (PC) board control system was developed, which allows adjustment of focus current in dependence of the power and the focus position. The main innovative aspects of this system is the ability to adjust online and continuously the focus current to the respective beam power during the slope.
THE OBJECTIVES OF THIS WORK ARE AS FOLLOWS:

- DETERMINATION AND OPTIMIZATION OF THE EB WELDING PARAMETERS ON VERY THICK CR-O STEELS WHICH ARE USED IN MANY INDUSTRIAL COMPONENTS, I.E.: PRESSURE VESSELS, HEAT EXCHANGERS, GAS AND STEAM TURBINES, ETC.
THREE EB EQUIPMENTS ARE INVOLVED IN THIS PROJECT, TO COMPARE ELECTRON BEAM CHARACTERISTICS AND WELD QUALITIES ON FOUR KINDS OF CR-MO STEELS: 2 1/4 CRMO (PLATES AND CAST), 9 % CRMO, 12 % CRMO.

THE NECESSARY STEPS TO ACHIEVE THESE GOALS ARE:
- THE RELATIONSHIP BETWEEN BEAM CHARACTERISTICS, WELD QUALITY AND OCCURENCES OF DEFECTS;
- THE OPTIMIZATION OF WELDING CONDITIONS IN PARTIAL AND FULL PENETRATIONS (75 TO 200 MM);
- THE OPTIMIZATION OF THE WELDING PROCEDURE FOR A GIRTH WELD;- NON DESTRUCTIVE AND DESTRUCTIVE TESTS OF THE WELDS.

THE ACHIEVEMENTS OF THESE TESTS ARE TO ALLOW THE PERFORMANCE OF FULL SCALE MOCK-UPS AS A DEMONSTRATION OF THE RESULT VALIDITY.

Ámbito científico (EuroSciVoc)

• ingeniería y tecnología › ingeniería eléctrica, ingeniería electrónica, ingeniería de la información › ingeniería electrónica › sistemas de automatización y control
• ciencias naturales › ciencias químicas › química inorgánica › metales de transición

Programa(s)

• FP1-BRITE - Multiannual research and development programme (EEC) in the fields of basic technological research and the applications of new technologies (BRITE), 1985-1988

Tema(s)

Datos no disponibles

Convocatoria de propuestas

Datos no disponibles

Régimen de financiación

CSC - Cost-sharing contracts

Coordinador

SOCIETE FRAMATOME

• Aportación de la UE: Sin datos
• Dirección: Tour Framatome ; 92084 PARIS LA DEFENSE ; Francia
• Coste total: Sin datos

Participantes (4)

AACHEN UNIVERSITY OF TECHNOLOGY

Alemania

• Aportación de la UE: Sin datos
• Dirección: Templergraben 55 ; 52056 AACHEN
• Coste total: Sin datos

Creusot Loire Industrie SA

Francia

• Aportación de la UE: Sin datos
• Dirección: 4 place de la Pyramide ; 92086 Paris la Défense
• Coste total: Sin datos

GEC Alsthom Turbine Generators Ltd

Reino Unido

• Aportación de la UE: Sin datos
• Dirección: Willans Works Newbold Road ; CV21 2NH Rugby
• Coste total: Sin datos

THE WELDING INSTITUTE

Reino Unido

• Aportación de la UE: Sin datos
• Dirección: Granta Park, Great Abington ; CB1 6AL CAMBRIDGE
• Coste total: Sin datos