HSD

1
HSD ADVANCED DESIGN METHODOLOGIES TO EXPLOIT
HIGH STRENGTH STEELS FOR PRESSURE EQUIPMENT
MANUFACTURE DGIII Contract Nr.
501983following an EPERC TTF2 EOI (January
1999 February 2001)co-ordinators C. Boucher,
A. Michel (IS)partners IS, G.Baylac, EMD
(ARMINES), AAB(TUW)
Appendix 4 (p. 1/7)
2
Objectives
Appendix 4 (p. 2/7)

• To demonstrate the present design codes may be
  adapted to allow for benefitting of the improved
  properties of fine grained TMCP and QT steels
• To provide informations to DGIII aiming at
  preparing recommendations for further work in
  support of standardisation

3
Work programme
Appendix 4 (p. 3/7)

• Enquiry on the use of HSS for PV manufacturing -
  literature survey and dissemination of a
  questionnaire to help to identify the needs
• Design of prototypes (welded and non-welded PV)
  for the experimental validation of the design
  code deviation
• DBA and DBF, fitness for purpose assessment
• Experimental validation (fatigue tests and burst
  tests)
• Reporting and Recommendations

4
Enquiry results
Appendix 4 (p. 4/7)

• 46 answers over 90 (60 companies)
• Main difficulties faced by the manufacturerswere
  identified
• PWHT (new fabrication and repair)
• HSS weld cracking
• procurement (flanges and fitting)
• etc.

5
Appendix 4 (p. 5/7)

• Most relevant problems addressed
• PWHT no PWHT after cold forming or for tempering
  and stress-relieving purpose
• Procurement use of standard normalised currently
  available flange and fitting
• Prototypes for testing
• Sphere in TMCP steel 460 MPa YS - 35 mm thick
  (as cold worked, no stress relieving)
• Cylindrical shell in QT steel 500 MPa YS - 25
  mm thick (as cold worked, no temper)
• Un-welded forged buffer vessel and screwed -in
  flat ends hydraulic accumulator in 34CrMo4 QT
  steel

6
Welded PV testing
Appendix 4 (p. 6/7)

• A detailed testing protocol has been defined (the
  ECOPRESS project co-ordinator participated to the
  protocol definition)
• NDT
• quasi-burst test
• NDT
• put artificial defects (spark-machining) in the
  most critical areas according to DBA
• fatigue testing (Ds 0 Pd), 500 cycles minimum
  life
• NDT

7
Future work
Appendix 4 (p. 7/7)

• Pressure test completion
• Final report recommendations to DGIII (by
  February 2001)
• Co-ordination vs. ECOPRESS
• Dissemination (EPERC, CEN, AFIAP conf. 2001)