Microstructural Development in HSLA-100 Steel Weld Metals
Abstract
Light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have been employed to examine the decomposition of austenite in high-strength low alloy 100 steels. The as-received plate had been quenched and tempered and low magnification imaging suggested that the microstructure comprised lath martensite and granular bainite. However, at higher magnifications, much of the so-called granular bainite was found to consist of equiaxed ferrite which contained pools of austenite and/or martensite. The tempering treatment yielded fine dispersions of epsilon-copper, with both the lath martensite and the granular bainite. Finally, the occasional observation of interphase precipitation in association with ferrite suggests that the proeutectoid ferrite reaction had initiated prior to quenching from the austenizing temperature. For samples which had been reaustenitized and ice-water quenched, the microstructure consisted primarily of lath martensite although some 'granular bainite' also observed. Slow (furnace) cooling from the austenitic range yielded an equiaxed grain structure which could be designated as granular bainite.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1990
- Accession Number
- ADA222105
Entities
People
- Paul R. Howell
Organizations
- Pennsylvania State University