Details:

Creators:
Fine, Morris E. ; Vaynman, Semyon ; Ghosh, Gautam
Fine, Morris E. ; Vaynman, Semyon ; Ghosh, Gautam Less -
Subject/TRT Terms:
[+]
Atmospheric Corrosion Construction Steel Copper Materials Tests Steel
DOI:
https://doi.org/10.21949/1404097
Resource Type:
Tech Report
Corporate Publisher:
Northwestern University (Evanston, Ill.). Infrastructure Technology Institute
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATION;NTL-HIGHWAY/ROAD TRANSPORTATION-Materials;
Abstract:
This research has shown that a Grade 70 construction steel of 1/2- to 1-inch plate thicknesses can be produced without a quench and temper or accelerated cooling from hot-rolling if the Cu content in the steel is sufficiently high. Coherent very fine bcc Cu precipitates form on air cooling providing strengthening to at least 70 Ksi. The yield strength decreases with plate thickness from 90 Ksi for 1/2- inch-thick plate to 78 Ksi for 1-inch-thick plate. Investigation of 2inch-thick plate is underway. While the fracture toughness of the steel is excellent when the hot-rolling temperature does not exceed 11500C, overheating to 12500C causes degradation in fracture toughness. This is related to growth of austenite grains and formation of Widmanstaten ferrite plates. Normalizing at 950 to 10500C restores the room-temperature impact fracture toughness to above 264 ft-lbs while maintaining the yield strength of 70 Ksi or above. No brittle heat-affected zone was formed during manual or automatic submerged arc welding without pre-heating or post-heating even at very high heat input. The fracture toughnesses in the plate and in the heat-affected zone were excellent. While the Cu in the HAZ dissolves when the temperature exceeds the solvus, it reprecipitates on cooling. Thus there is little degradation or little change in hardness in the HAZ. Since the carbon content is low, there is no decrease in fracture toughness in the HAZ. Estimated by equations developed at Northwestern University, atmospheric corrosion losses for NUCu steel are not higher than those for other weathering steel grades.
Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:0e9c895da7103e37d2c29b31ee98ca5fb942ae4b8c064a5f2e41761de6895eb0
Download URL:
https://rosap.ntl.bts.gov/view/dot/13051/dot_13051_DS1.pdf
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