Details:

Creators:
Manuel, Michele V. ; George, Edward
Manuel, Michele V. ; George, Edward Less -
Corporate Creators:
University of Florida
Subject/TRT Terms:
[+]
Bridge Construction Fatigue (Mechanics) Milling Plasma Arc Cutting Weathering Steel
Publication/ Report Number:
BDV31-977-02
Resource Type:
Tech Report
Geographical Coverage:
United States
Corporate Publisher:
Florida. Dept. of Transportation
Abstract:
High-strength low-alloy (HSLA) weathering steels are the conventional material used for non-redundant fracture-critical members in bridge construction. Guidelines have been put in place by state

Departments of Transportation (DOTs) to prevent material suppliers from making scribe marks that

will remain on the surface of fracture-critical members when in service, due to the possibility of

degrading mechanical properties. Currently, any automated scribing marks allowed, namely

mechanical milling, are either cut off of the member or subsequently welded over, thereby effectively

removing them prior to service. All other markings are either manually die-stamped or spray-painted

on. The lack of an automated capability to place markings on weathering steels slows production, and

markings are often accidentally removed during sand blasting or shipping, which causes additional

problems for the manufacturer and recipient. There is a need to establish safe, automated methods of

scribing fracture-critical members such that markings will remain throughout the production process,

but will not compromise the integrity over the lifetime of the part. Three automated techniques were of

interest in this study as they are often already in the manufacturing process. These include mechanical

milling, plasma scribing, and laser scribing. In this study, a microstructural evaluation of 50W

weathering steel was conducted to understand and characterize the effect of the three markings on

microstructural evolution and mechanical properties. Plasma scribing resulted in the most noticeable

surface marking. S-N curves generated through fatigue testing showed no measurable difference in

fatigue life between marked and unmarked material.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:1e57a7034ee9da67c736f0dba2aeca6c5f5c11959bd81c0b2b582abb16cffee3
Download URL:
https://rosap.ntl.bts.gov/view/dot/28411/dot_28411_DS1.pdf
File Type:

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