Accession Number:

ADA063133

Title:

A Correlation between SCC Path, Hardness, Microstructure, and Microsegregation in HY-130 E14018 Weld Metal,

Descriptive Note:

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s):

• Fraser,F. W.
• Metzbower,E. A.
• Stoop,J.

Report Date:

1978-12-22

Pagination or Media Count:

21.0

Abstract:

In an investigation of cold cracking in the weld metal of an HY-130 E14018 weldment, variations in hardness, microstructure, and microsegregation were related to the path of the fracture which propagated through the centers of adjacent weld beads. Evidence of solute rejection was found in the formation of pools of solute, in the cell boundaries, where a transition from a cellular to a cellular-dendritic solidification mode had taken place. The composition of the solute pools was determined by microprobe analysis. Microhardness measurements showed a gradient within each weld bead, with hardness increasing from the fracture edge to the fusion zone at the interface of the weld metal and the base metal. Metallographic examination showed the microstructure at the fracture edge to be largely bainitic, whereas the harder weld metal, near the fusion zone, was predominantly martensitic. Measurements within the fusion zone showed a slight decrease in hardness, and microprobe analysis showed this to be a zone of melted but incompletely mixed base metal and weld filler metal. Author

Descriptors:

• *MICROSTRUCTURE
• *STEEL
• *WELD METAL
• *CRACK PROPAGATION
• *SEGREGATION(METALLURGY)
• *STRESS CORROSION
• *HARDNESS
• FRACTOGRAPHY
• CORRELATION TECHNIQUES

Subject Categories:

• Properties of Metals and Alloys
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE