Developments and Applications of a Corrosion Resistant Stainless Bridge Steel:

A709 Grade 50CR (A1010)Matthew H. Hebdon, Ph.D., P.E.

Virginia Tech

63rd Annual Structural Engineering ConferenceMarch 1, 2018 - Lawrence, KS

Contributions from:• VTRC/VDOT

• Jason Provines• Stephen Sharp• Bill Via

• Graduate student• Isaac Groshek (AECOM)

• Industry• Ronnie Medlock

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Outline• Background

• History/Material

• US Bridge Projects• VDOT: Route 340 Bridge

• Research• Corrosion applications

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Limit State: Corrosion

• Significant impact on ‘life-cycle cost’

• Prevention strategies4

Limit State: Corrosion• Electro-chemical process

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Limit State: Corrosion• Corrosion prevention = environment specific

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Limit State: Corrosion• Active corrosion

• Large corrosion product• Continual flaking away

• Passive Corrosion• Small corrosion product• Tight adherence

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ASTM A709 Gr50CR (A1010)• UNS S41003

• ArcelorMittal-US Market• Marketed as Duracorr®• Corrosive Applications

• Attractive for Bridges• Improved corrosion

resistance• Economical

• Added into A709 - 2017

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(ArcelorMittal, 2015)

(ArcelorMittal, 2015)

Material Properties• Dual-phase Stainless Steel

• Ferrite/Tempered Martensite• 10.5% - 12% Chromium• 1.5% Nickel

• Similar Mechanical Behavior as A709 Gr50

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Comp., wt. %C 0.03Mn 1.5P 0.04Si 1Cr 10.5-12.5Ni 1.5

North American Bridge Projects

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Fairview Road Bridge• Colusa County, California, 2004• FHWA IBRC program• Multi-cell Bridge Girder modules

• 0.16in plates• 50% weight reduction

11 (Fletcher, 2011)

ArcelorMittal Bridge• Coatesville, Pennsylvania, 2012• 1st A1010 plate girder bridge in US• Plate range: 0.375in-1.5in• E309L weld material

12 (ArcelorMittal, 2015)

Dodge Creek, Mill Creek Bridges• Sutherlin, Oregon, 2012, 132.5ft

• High time-of-wetness (TOW) • Astoria, Oregon, 2013, 123ft

• Columbia River estuary

13 (Seradj, 2015)

Salix Interchange Bridge• Salix, Iowa, 2016• 4-span bridge, 6 girder lines

• 2 A1010 girder lines (fascia, 1st interior)

14 (Iowa DOT, 2016)

A1010 Girders

Route 340 Bridge• Waynesboro, Virginia, 2017• Why A1010?

• Industrial site upstream of bridge• Proximity to Water• Aesthetics

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Route 340 Bridge• 2 equal spans of 110 feet• 1st A1010 Bridge to include:

• Haunched girders• Bolted splice w/ stainless steel fasteners• A1010 cross-frames & diaphragms• Non-metallic blast cleaning

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Route 340 Bridge: Fabrication• Safety: Hexavalent chromium in fumes• Cannot be cut w/ traditional oxy-acetylene

• Use plasma, laser, or water jet• Requires dedicated shop area and tools• Similarities to A709

• Drilling, bending, grinding

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Route 340 Bridge: Welding• 309L Electrodes

• Buy America challenges• 309L-C electrodes procured (1st time used)

• Interpass temperature limitations• Submerged arc welding (SAW) process

• Used for Oregon DOT A1010 bridges

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Route 340 Bridge: NDE• Dye penetrant (PT) – OK• Magnetic particle testing (MT)

• Cannot inspect filler in CJP welds (non-magnetic)• Ultrasonic testing (UT) – sensitive to grain size, OK• X-ray testing (RT)

• Challenges with digital x-ray with thinner plate material

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Route 340 Bridge: Bolting• Stainless steel fastener assemblies

• ASTM A193 Grade B8 bolts, A194 nuts, 303 Washers• New tightening specs needed

• Less force per bolt than A325 bolts (30k vs. 39k)• Lubrication is important

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Route 340 Bridge: Cross-Frames• A1010 rolled shapes do not exist• Fabricator elected to use bent plate shapes• Bent, then welded (SAW) into cross-frames

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Route 340 Bridge: Erection• Began placing girders in December 2016

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Route 340 Bridge: Patina• Girders came in 3 shipments

• Day 1: Clear, sunny day• Day 2: Snow showers, de-icing salt applied to roadway• Day 3: Rain showers

• Will use steel shot blasting in the future

23Day 1 Day 2 Day3

Route 340 Bridge: Cost• Winning lump sum bid for A1010 girder = $2.17M

• Erected A1010 girder bid cost (incl. material):

• Compare with inflation-adjusted decadal weighted averages for:

• A709 Gr50W (plain) = $1.68/lb• A709 Gr50 (HDG) = $2.72/lb

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Vendor Girder bid cost

Sub Payments

Value Added

Unit Cost Based on Invoiced #s

Prime Contractor $2,170,000 $323,272 $0.89/lbErection Sub $1,846,728 $121,875 $0.33/lbFabrication Sub $1,724,853 $1,252,403 $3.44/lbMaterial Sub $472,450 $472,450 $1.30/lb

$5.95/lb

Route 340 Bridge• Opened to traffic in June 2017, ahead of schedule

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Research: Corrosion• Three primary concerns for bridge

applications:• General Corrosion• Galvanic Corrosion

• Dissimilar metals• Connections

• Crevice Corrosion• Moisture infiltration• Increased acidity

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Research: Corrosion• Accelerated Cyclic Corrosion Testing

• Modified SAE J2334 Surface Vehicle Standard• Produce corrosion products expected in service

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Research: General Corrosion• FHWA (2011):

• 10x A709 Gr50W

• VT (2017):• Orientation

• 10x – Near Vertical• 4x – Near Horizontal

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Research: General Corrosion• 4 Common Bridge Materials

• A709 Gr50CR (A1010)• A709 Gr50• A709 Gr50W• A709 Gr50 HDG

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Research: General Corrosion

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Research: Galvanic Corrosion• A1010 plates w/ dissimilar carbon steel plate

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Research: Galvanic Corrosion• A1010 plates w/ dissimilar carbon steel plate

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Corrosion Rate (μm/cycle)A1010 Plate Carbon Steel Plate

Control Galvanic Control GalvanicA709 Gr50 1.95 1.46 8.39 8.93A709 Gr50W 1.79 1.80 8.06 9.09A709 Gr50 HDG 1.44* 0.85* 1.62* 2.68*

Research: Galvanic Corrosion• A1010 plates w/ dissimilar fasteners

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HDG

B6

A490

Research: Galvanic Corrosion• A1010 plates w/ dissimilar fasteners

Research: Galvanic Corrosion• A1010 plates w/ dissimilar fasteners

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A325 Type 1

A325 Type 3

A490 A325 HDG

B6 (SS)

B8(SS)

Research: Crevice Corrosion• A1010 to A1010 plates

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Research: Crevice Corrosion• A1010 to A1010 plates

• Corrosion rate = ~4x A1010 control plates~1/4x Gr50W control plates

• Significant contribution to galvanic corrosion

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Research: Corrosion• Recommendations:

• General Corrosion• A709 Gr50CR = 4-10x corrosion resistance

– In highly corrosive environments

• Galvanic Corrosion• Target stainless alloys where possible/economical• Otherwise:

– HDG plates & fasteners– Until zinc depletion

• Crevice Corrosion• HDG plates = cathodic protection, zinc migration

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Recent A1010 Research• Corrosion testing (FHWA, 2011; ODOT)• Weldability/fabrication (ODOT, VDOT) • Galvanic corrosion (Virginia Tech, 2016)• Bolt slip coefficient (VTRC, 2017; Canada)

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Ongoing/Upcoming Research• Weldment material properties• Fabrication concerns• Hybrid applications• Galvanic corrosion of welds• Corrosion resistant bolts• Welded beam end repairs• New bridge construction/repair projects

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Conclusions• Growing interest in Stainless Steel in the

North American bridge market• Corrosive environments• Achieve desired design life• Economy:

• Balance initial vs. lifecycle cost• Targeted applications

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Questions?

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References• ArcelorMittal. (2015). Duracorr: Life-Cycle Cost-Effective

12% Chromium Stainless Steel. Chicago, IL.• Fletcher, F. (2011). Improved Corrosion-Resistant Steel

for Highway Bridge Construction. FHWA-HRT-11-062. McLean, VA.

• Iowa DOT. (2016). Iowa A1010 experience. In AASHTO T-14 Meeting, August 2016.

• Seradj, H. (2015). Oregon’s ASTM A1010 Bridges. In Iowa DOT A1010 Steel Workshop. Ames, IA

• Via, W., Sharp, S. (2017). VDOT Experience with ASTM A1010 Steel Bridge Fabrication. TRB Annual Meeting. Washington, D.C.

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