Microstructural evaluation of Fe-3Cr-1. 5Mo-0. 1V thick-section electron beam welds

Conference · Mon May 19 04:00:00 EDT 1986

OSTI ID:5065554

Vitek, J M; Packan, N H; David, S A

The iron-base alloy 3Cr-1.5Mo-0.IV is intended to be used for high-temperature applications. The feasibility of welding heavy-section plates (102-mm thick) of this alloy by high-power, electron-beam welding was investigated. An evaluation of the mechanical properties of these welds, reported in a companion study, indicated that electron-beam welding is an attractive process for joining this type of alloy. The present study is concerned with the evaluation of the weld and heat-affected zone (HAZ) microstructures by means of optical and electron microscopy. The weld and immediately surrounding HAZ structures are bainitic with thin areas of retained austenite between the bainite laths. Further away from the weld, the HAZ structures consist of bainite and proeutectoid ferrite and correspond to a drop in the microhardness, which goes through a minimum. Beyond the minimum, the HAZ structure is tempered bainite. The various structures observed can be related to the maximum temperature experienced during the welding cycle and its relationship to the A/sub c1/ and A/sub c3/ temperatures of the alloy. Except for the small region containing bainite plus ferrite, the structures throughout and weld and HAZ are basically bainite tempered to various stages; these variations can be eliminated by a proper post-weld heat treatment.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5065554
• Report Number(s): CONF-860594-9; ON: DE86014635
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-MOLYBDENUM STEELS
CRYSTAL STRUCTURE
ELECTRON BEAM WELDING
EVALUATION
FABRICATION
HEAT AFFECTED ZONE
IRON ALLOYS
IRON BASE ALLOYS
JOINING
JOINTS
MICROSTRUCTURE
PLATES
STEELS
WELDED JOINTS
WELDING
ZONES