Improved Materials for Pot Hardware

Scope:

The galvanizing of steel sheet by continuous hot dipping in a molten bath of zinc containing various amounts of aluminum is the most efficient and economical method of providing corrosion protection to sheet steel. There are 57 companies that run galvanizing lines in the USA.

Galvanizing line hardware such as bearings, rollers, guides, and stabilizers, are subject to corrosion and deterioration due to being continually submerged in the zinc/aluminum solution. Downtimes occur approximately every two weeks for maintenance and replacement of the galvanizing line hardware.

Yield loss, lost revenue, downtime, and re-machining of hardware on one of the galvanizing lines at one of the industry participants in this project is estimated at $800K/year with a cumulative total loss of approximately $46 million/year.

The revised Steel Industry Technology Roadmap published by the American Iron and Steel Institute states that life extension of molten metal hardware materials by an order of magnitude is a high priority R&D need. The current proposal is in response to this high-priority R&D need.

The project is funded by U.S. DOE Office of Industrial Technologies Steel Vision of the Future Solicitation. The total project cost is $1,551,000 per year with an overall project budget for three years of $4,653,000. The industry partners and WVU will provide $788,000 per year in cost-share for a total three-year cost-share of $2,364,000 in cash contributions, and in-kind goods and services.

Objective:

The research objectives of this project are to develop new bulk materials and surface treatments/coatings for life improvement of molten metal bath hardware and bearings in continuous hot-dip process. Development of such new materials would allow (1) energy savings, (2) reduction of line downtime and yield loss, (3) improvement in overall sheet quality, (4) reduced cost of repair and replacement cost of corroded components, (5) environmental improvements, and (6) improved economics.

The project goal is to result in extension of component life by a factor of 10 with estimated energy savings of 2 trillion BTU/year and cost savings of up to $46 million/year.

Partners:

International Lead & Zinc Research Organization ILZRO
Weirton Steel
Wheeling Nisshin Steel
California Steel Industries
Duraloy Technologies
Stoody Company
AK Steel
ASB Industries Inc.
Deloro Stellite
Ellison Surface Technologies
Fontaine Engineering, Inc.
Metaullics Systems Co.
USSteel
Praxair Surface Technologies, Inc.
Teck Cominco
U.S. DOE Office of Industrial Technologies
UES Software Inc.
Vesuvius McDanel
Oak Ridge National Laboratory

 

Researchers:

Ever J. Barbero, PI, WVU
Xingbo Liu, WVU
Bruce Kang, WVU
John Loth, WVU
Bhaskaran Gopalakrishnan , WVU
Vinod Sikka, ORNL
Carl Irwin, NRCCE

Students:

James Snider
Mark Bright
Ryan Ware
Vishnu Rachamalla
Shalini Rangarajan
Bharath Kumar Venkataraman

Staff:

Sharon Smyth

Accomplishments:

WVU Wear Tester: A laboratory device was constructed and testing methodology was developed that permits accurate and quick evaluation of wear characteristics while submerged in molten metal.
 

 

 

 

 

 

Metaullics 2012 XT: This novel material has been successfully tried in actual production lines at ?, leading to energy savings estimated at ? BTU/yr. when extrapolated to % market penetration in North America.

Deloro-Stellite T401 PTA overlay: This novel material has been successfully tried in actual production lines at Wheeling Nishing, leading to energy savings estimated at ? BTU/yr. when extrapolated to % market penetration in North America.

Roller Bearing Patent: Bearing life extender for conveyor type rollers. Rollers used on conveyors and inside the zinc-pot of a steel-sheet galvanizing line are usually driven by friction between the roller and the belt or sheet. To keep rollers from stalling, the bearing diameter is minimized. The allowable bending stress in the bearing shaft limits its length. Rollers operating in high temperature furnaces or in a hot zinc pot of a steel galvanizing line often have limited or non-existent bearing lubrication. In such cases, bearings of small diameter and limited length result in high contact pressure and short lifetime. Inside a zinc-pot, bearing life often does not exceed one week of operation. Most of these bearings are designed to have a stationary bearing housing with the roller shaft rotating inside. For small diameter rollers such shafts are an integral part of the roller. For cylindrical shell type rollers, short shafts are welded to plugs, which are then welded to each end of the roller. The herein disclosed "Bearing Life Extender For Conveyor Type Submerged Rollers" utilizes bearings, which are smaller in diameter and longer, without an increase in shaft bending moment! This is made possible by changing from a rotating cantilevered shaft to a stationary shaft strengthened to be substantially non-deflecting on either side of the bearings. Such a stationary shaft can be smaller in diameter to reduce bearing friction torque and stall problems. In addition such a shaft can have increased bearing contact area and assure bearing alignment, all of which contribute to increased bearing life.

Links

http://iofwv.nrcce.wvu.edu/projects/steel/HotDippingSummary.cfm

Industrial Assembly:
(Click on the image for a bigger picture)

Galvanize Line Lowboy Assembly Lowboy-1

Galvanize Line Lowboy Roll Assembly Lowboy-2

Line Stabilizer and Sink Roll Assembly Sinkroll-1