Drop-Weight-Tear-Test Equipment Energy Calibration Program

Technical Report · Sat Oct 01 04:00:00 EDT 1988

OSTI ID:6588091

Eiber, R J

The Drop-Weight-Tear-Test (DWTT) energy absorption has not previously been considered as a measure of fracture toughness from this test. The DWTT was originally planned to define the fracture appearance transition temperature of line pipe. The test has been very successfully used for this purpose for the past 20 years. During this period of DWTT usage, the need for a toughness measurement to control ductile fracture propagation has seen the application of a Charpy shelf-energy in addition to a DWTT or Charpy shear area requirement in the specification of line-pipe properties. The purpose of exploring energy measurements in the DWTT is to determine if both fracture appearance and toughness can be obtained from a single test. To this end, a number of individual steel companies and gas-transmission companies have been examining the use of a DWTT energy measurement. Also, the Round Robin Program on the precracked drop-weight-tear test (DWTT) indicated that the energy measurements by the 12 participating laboratories had a coefficient of variation (standard deviation/average) that is about 30 percent larger than for the Charpy V-notch test. Also, the average energy variations between the various laboratories were quite large. This suggested that there was a need for calibrating the equipment used for energy measurements. It also suggested that equipment design may be a contributing factor. The objective of this program is to obtain reference steels that are uniform and of varying energy levels so that reference specimens can be supplied to a laboratory to assess the accuracy and precision of their DWTT energy measuring equipment. 7 figs., 5 tabs.

• Research Organization: Battelle Columbus Div., OH (USA)
• OSTI ID: 6588091
• Report Number(s): AGA-9006595; ON: TI89006595
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420205* -- Engineering-- Transport & Storage Facilities-- (1980-)
ALLOYS
CALIBRATION
DATA
DESTRUCTIVE TESTING
FAILURES
FRACTURES
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS TESTING
NUMERICAL DATA
PIPELINES
PIPES
STEELS
TESTING