Accession Number : ADA137145

Title :   Effects of Preheat on Weldments of NICOP Steel.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Burna,R F

PDF Url : ADA137145

Report Date : Sep 1983

Pagination or Media Count : 72

Abstract : Shielded metal arc weldments of Armco Steel Corporation's NICOP class 3, 19mm (3/4 inch) plate, conforming to ASTM A710 grade A, were studied to provide information concerning the microstructure in the heat affected zone (HAZ) of weldments fabricated with and without preheat. Microhardness, scanning electron microscopy and transmission electron microscopy were used to determine the effect of preheating on the microstructure. Similar microstructures in the preheat and non-preheat samples were observed. The microstructures were polygonal and acicular ferrite in the base and base/HAZ regions and increasing amounts of bainite and auto tempered martensite islands near the fusion line. From the point of view of microstructure, NICOP appears to be weldable without preheating.

Descriptors :   *Steel, *Weldments, *Thermal properties, High strength alloys, Heat treatment, Welding, Microstructure, Fabrication, Microhardness, Polygons, Ferrites, Bainite, Martensite, Fusion welding, Cracking(Fracturing), Toughness, Electron microscopy, Theses

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE