Accession Number : ADA299359

Title :   Observations of Star Fracture and Longitudinal Splitting in BIS 812 EMA and Q1N Submarine Construction Steels,

Corporate Author : DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)

Personal Author(s) : Burch, I. A. ; Saunders, D. S.

PDF Url : ADA299359

Report Date : MAR 1995

Pagination or Media Count : 31

Abstract : The tensile properties and fracture behaviour of two submarine construction steels, BIS 812 EMA and Q1N, have been studied. Their properties and fracture behaviour were measured over a wide range of test temperatures utilizing plain and notched tensile specimens. The yield strength of both materials was found to increase with decreasing temperature and the fracture surface appearance of these steels was also temperature dependent. Under certain conditions star fracture was exhibited, rather than the usual cup-and-cone type fracture. The predominance of the star type fracture increased with decreasing temperature in both plain and notched tensile specimens, however, it was suppressed by notching. This paper describes in detail the fractographic features of the surfaces and proposes that a range of conditions exist under which star fracture occurs in these materials. (AN)

Descriptors :   *TENSILE PROPERTIES, *FRACTURE(MECHANICS), *SUBMARINES, *STRUCTURAL STEEL, TEST AND EVALUATION, SCANNING ELECTRON MICROSCOPES, SURFACE ANALYSIS, MICROSTRUCTURE, CRACKING(FRACTURING), HIGH STRENGTH ALLOYS, TEMPERATURE GRADIENTS, SHEAR STRESSES, DUCTILITY, YIELD STRENGTH, AUSTRALIA, ELECTRON SPECTROSCOPY, ACCELERATED TESTING, SURFACE TENSION, NOTCH TOUGHNESS, MARTENSITE, RADIAL STRESS, SHIP STRUCTURAL COMPONENTS, LOW ALLOY STEELS.

Subject Categories : Properties of Metals and Alloys
      Submarine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE