Accession Number : ADA190255

Title :   Cracking Tendancies of Restrained Welds in High Strength Low Alloy Steels under Hyperbaric Conditions.

Descriptive Note : Master's thesis,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF OCEAN ENGINEERING

Personal Author(s) : Ni, Randolph

PDF Url : ADA190255

Report Date : Jun 1987

Pagination or Media Count : 118

Abstract : The weld cracking tendancies of two newly developed controlled rolled and accelerated cooled high strength low alloy (HSLA) steels are compared with a standard normalized steel of approximately the same ultimate tensile strength (50 kg/mm2). All steels were welded with the shielded metal arc welding process at 0, 100, and 200 psig. Welding was conducted in a hyperbaric chamber under conditions of 100% humidity, using the Lehigh self restraint weld cracking test. A literature and mail survey was conducted on current U.S. practices in underwater welding using the shielded metal arc process. Test plates were subjected to macrascopic examinations to determine the extent of any existent cracking. it was found that the low carbon equivalent HSLA steels exhibited an excellent resistance to cracking, even when welded without the use of preheat. The general tendency for cracking susceptibility to lower as the cracking susceptibility factor (Pw) lowers was validated, even under hyperbaric conditions. However, it was substantiated that the current theories used to determine cracking susceptibility may be too conservative in predicting cracking susceptibility for HSLA steels.

Descriptors :   *STEEL, *HIGH STRENGTH ALLOYS, CARBON, CRACKS, HYPERBARIC CONDITIONS, SURVEYS, TENSILE STRENGTH, TEST EQUIPMENT, WELDING, WELDS, OFFSHORE STRUCTURES, REPAIR, STRESSES, THESES, HYPERBARIC CONDITIONS, MARINE ENGINEERING

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE