Accession Number : ADA314622

Title :   Application of Fracture Toughness Scaling Models to the Ductile-to-Brittle Transition.

Descriptive Note : Technical rept. Sep 92-Sep 94,

Corporate Author : NAVAL SURFACE WARFARE CENTER ANNAPOLIS MD

Personal Author(s) : Link, R. E. ; Joyce, J. A.

PDF Url : ADA314622

Report Date : JAN 1996

Pagination or Media Count : 40

Abstract : An experimental investigation of fracture toughness in the ductile-brittle transition range was conducted. A large number of ASTM A533, Grade B steel, bend and tension specimens with varying crack lengths were tested throughout the transition region. Cleavage fracture toughness scaling models were utilized to correct the data for the loss of constraint in short crack specimens and tension geometries. The toughness scaling models were effective in reducing the scatter in the data, but tended to over-correct the results for the short crack bend specimens. A proposed ASTM Test Practice for Fracture Toughness in the Transition Range, which employs a master curve concept, was applied to the results. The proposed master curve over predicted the fracture toughness in the mid-transition and a modified master curve was developed that more accurately modeled the transition behavior of the material. Finally, the modified master curve and the fracture toughness scaling models were combined to predict the as-measured fracture toughness of the short crack bend and the tension specimens. It was shown that when the scaling models over correct the data for loss of constraint, they can also lead to non-conservative estimates of the increase in toughness for low constraint geometries.

Descriptors :   *SCALE MODELS, *TOUGHNESS, *FRACTURE(MECHANICS), *DUCTILE BRITTLE TRANSITION, TEST AND EVALUATION, CRACKS, BENDING, STEEL, TENSION.

Subject Categories : Properties of Metals and Alloys
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE