Att välja material till bärande konstruktioner

Att välja material till bärande konstruktioner Hasse Groth & Thérèse Sterneland Avesta Research Center Outokumpu Älvsjö 2017-10-25

Innehåll 1. Vad är rostfritt stål och olika typer? 2. Duplexa rostfria stål 3. Att välja material 4. Erfarenheter 10/30/2017 2

Vad är rostfritt stål? Järn med tillsats av minst 10.5% krom Naturligt bildad passivfilm 20-30 Å = 0.000 002-0.000 003 mm Självläkande Vykort passivfilm Fe + >10.5% Cr 1 mm 10/30/2017 3

Det finns rostfritt. och sen så finns det syrafast 10/30/2017 4

Olika typer av rostfria stål Kombinationen av legeringselement ger en mikrostruktur som ger vissa typiska egenskaper. Ståltillverkare gillar denna indelning! (Tillverkning Världen/Sverige) Austenitiska stål Krom + Nickel (Mo, N). Formbarhet, svetsbarhet. Vanligast. (80/70%) Ferritiska stål Krom. Magnetiskt. Vanligt förekommande. (19/1%) Duplexa stål Mycket Krom lite Ni, Mo, N. 50% ferrit-50% austenit Hög hållfasthet. Växer snabbast. (1/29%) Martensitiska stål Krom + ganska mycket kol. Ej i Eurocode Hög hållfasthet, härdbara. Knivstål. 10/30/2017 5

Olika typer av rostfria stål-olika egenskaper Austenitiska stål Från milda till aggressiva miljöer Ferritiska stål Lämpliga i mildare miljöer Duplexa stål Från milda till aggressiva miljöer, hög hållfasthet Martensitiska stål Lämpliga i milda miljöer där hårdhet krävs 10/30/2017 6

What is Duplex Stainless Steel? Duplex stainless steel has a ferritic-austenitic microstructure The phase balance is approximately 50% ferrite and 50% austenite Duplex stainless steel combines most of the beneficial properties of ferritic and austenitic steels The duplex microstructure contributes to high strength and high resistance to stress corrosion cracking 8

Duplex- a long history at Outokumpu Dec 23, 1930 Seawater 453S (~ASTM 329) Brobeck cooler in grade 453 S 9

History Second generation Duplex Process development (AOD) made it possible to reduce the carbon content and to alloy with nitrogen. The nitrogen improved the formation of austenite after welding 2205 was invented in the 1970 s 10

History Third generation Duplex Super duplex Grades with Cr content 25% or more High levels of Cr, Mo, N and sometimes W give high resistance to localized corrosion Lean duplex Grades with low Ni content often replaced with Mo and N 11

Forta range 12

Product performance comparison Yield strength vs. corrosion resistance Forta range Duplex PRE = % Cr + 3.3 x % Mo + 16 x % N. Yield strength (R p0.2 ) uses EN 10088-2 minimum values for cold rolled strip 13

Positioning of Duplex grades An excellent combination of high strength and corrosion resistance 600 550 500 Forta LDX 2404 Forta EDX 2304 Forta LDX 2101 Forta DX 2205 Hot coil Forta SDX 2507 Strength, R p0.2 [MPa] 450 400 350 300 250 200 150 Duplex Austentic Forta DX 2304 Supra 316L/4404 Ultra 317L Core 304L/4307 Supra 316L/4436 Ultra 4439 Ultra 904L Ultra 654 SMO Ultra 4565 Ultra 254 SMO Corrosion Resistance, CPT typical 14

Duplex products HRP(P), Quarto Plate: t = 2-100* mm CPP(H), coil and plate: t = 4-10* mm CR (C), coil, strip & sheet: t = 0.1-6* mm Billet, wire rod, bar and rebar Welded tube and pipe Fittings Structural profiles - Duprof : 6 m as standard, max 13 m *Max/min. thickness grade and width dependent. 15

Duplex = Austenitic + Ferritic structure Ferrite Austenite Duplex 16

High Mechanical Strength Solid Solution hardening Atoms of another size than the pure metal is causing a disorder in the material which leads to hardening. Nitrogen is an example of a small atom that solutes between the iron atoms in stainless steels. 17

General characteristics of Forta range Duplex products Courtesy of Outotec. High mechanical strength (Rp min > 400 MPa) High resistance to localized corrosion (PRE 26 to 43) and stress corrosion cracking High wear resistance Low thermal expansion High energy absorption Good fabricability Cost effective and sustainable solutions 18

Applications: Forta range duplex Storage tanks Pressure vessels Bridge components Flexible pipes (Oil & Gas) Blast walls (Offshore) Thickeners (Mineral processing) Water gates Courtesy of IKM dsc Engineering 19

Korrosionsmotstånd, några vanliga stål Outokumpu EN Struktur Cr Ni Mo N PRE* Moda 4016 1.4016 ferrit 16.2 16 Core 4509 1.4509 ferrit 18.0 18 Core 4307 1.4307 austenit 18.1 8.1 18 Core 4404 1.4404 austenit 17.2 10.1 2.1 24 Ultra 254 SMO 1.4547 austenit 20.0 18.0 6.1 0.20 43 Forta LDX 2101 1.4162 duplex 21.5 1.5 0.3 0.22 26 Forta DX 2205 1.4462 duplex 22.0 5.7 3.1 0.17 35 Forta SDX 2507 1.4410 duplex 25.0 7.0 4.0 0.27 43 *PRE, Pitting Resistance Equivalent, PRE = %Cr + 3.3 %Mo + 16 %N PRE är ett grovt verktyg för att rangordna olika rostfria ståls motstånd mot punktfrätning 10/30/2017 21

Punktfrätningsegenskaper Kritisk punktfrätningstemperatur, ASTM G150 100 90 80 70 60 50 40 30 20 10 0 1.4016 1.4521 1.4307 CPT, C 1.4404 1.4432 Ultra 904L (1.4539) Ultra 254 SMO (1.4547) Forta LDX 2101 (1.4162) Forta DX 2304 (1.4362) Forta DX2205 (1.4462) Forta SDX 2507 (1.4410) 10/30/2017 22

Det finns rostfritt. och sen så finns det syrafast 10/30/2017 23

Urgammal tumregel: Rostfritt inomhus Syrafast utomhus 10/30/2017 24

Korrosivitetsklasser (ISO 9223) och erforderliga rostfria stål ISO Corrosivity Typical environments Grades C1 Very low Dry or cold zone: Central Arctic/ Antarctica and certain deserts. 1.4016, 1.4307, 1.4162 C2 Low Temperate zone: rural areas and small towns. Dry or cold zone: deserts and subarctic areas. C3 Medium Temperate zone: urban areas and costal areas with low deposition of chlorides. Subtropical and tropical zone: areas with low pollution. C4 High Temperate zone: polluted urban areas, industrial areas, costal areas without spray and exposure to de-icing salts. Subtropical and tropical zone: areas with medium pollution. C5 Very high Temperate and subtropical zone: industrial areas, coastal areas and sheltered positions on coast line. CX Extreme Subtropical and tropical zone: extreme industrial areas, coastal and offshore areas. 1.4016, 1.4307, 1.4162 1.4301, 1.4404, 1.4162, 1.4362 1.4404, 1.4162, 1.4362, 1.4462, 1.4539, 1.4410, 1.4547 1.4462, 1.4539, 1.4410, 1.4547, 1.4565, 1.4652 1.4410, 1.4547, 1.4565, 1.4652 10/30/2017 25

Eurocode 3: EN 1993-1-4:2006 10/30/2017 26

Eurocode 3: EN 1993-1-4/A1:2015 Corrosion Resistance Factor CRF = F1 + F2 + F3 F1 = Risk of exposure to chlorides from salt water or deicing salts; F2 = Risk of exposure to sulfur dioxide; F3 = Cleaning regime or exposure to washing by rain. 10/30/2017 27

EN 1993-1-4/ A1:2015 10/30/2017 28

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Effekten av ytfinhet Forta LDX 2101, 2 års exponering vid Bohus Malmön, Svenska västkusten Ra 0.2 µm Ra 0.5 µm Ra 0.8 µm Finare ytor mindre risk för initiering av korrosion Missfärgning på ytan - Estetiskt, påverkar ej hållfasthet 10/30/2017 30

Påverkan av atmosfären Chrysler Building, New York, byggd 1930. Paneler i typ 1.4301 10/30/2017 31

Case: Gateway Arch, USA Stainless steel load bearing structure made in 1965. Arch design included load bearing, welded, stainless steel plate in grade 316 (1.4401). Inspection after 50 years Dirty, but in good shape! At that time - Minimal structural research, no duplex It was found that structural research was needed! 10/30/2017 32

Hur mycket rostar 1.4404 på ett tak i Stockholm? 1) Hur lång tid tar det innan 1 gram försvinner på en 1 m 2 yta takplåt 1.4404? (Tips: Materialet är beständigt i denna miljö. Det regnar på plåten regelbundet.) 2) En takplåt är normalt 0.5 mm tjock och väger 4 kg/m 2. Hur lång tid tar det innan 0.1 mm försvinner? Källa: Korrosionsinstitutet/KIMAB 10/30/2017 33

Vanliga duplexstål i broar Forta DX 2205, 1.4462 Forta DX 2304, 1.4362 Forta LDX 2101, 1.4162 Forta LDX 2404, 1.4662 Nytt

Inspection of Duplex bridges To collect field experience of stainless steel bridges. Observe and record the condition and performance of various stainless steel components at site. Acknowledgement Sukanya Hägg Mameng och Jan Björk Document and inform the designers of future stainless steel structure by providing a reference point for past sucessful applications. To provide data for future design standard revisions, EN 1993-1-4, Annex A relating to material selection.

Inspekterade broar CRC II, III CRC II, III CRC III Millenium, 2000 Grade 1.4462 Flen Bridge, 2009 Grade 1.4162 CRC II, III Celtic Gateway, 2006 Grade 1.4362 Sicklauddsbron, 2002 Grade 1.4462 CRC III CRC IV Zumaia, 2008 Grade 1.4462 UK Nynäshamn, 2011 Grade 1.4162 CRC II, III Spain CRC III Puerto Arrupe 2003 Grade 1.4362 Sölvesborg, 2013 Grade 1.4162 CRC II, III CRC II, III CRC IV, V Anorga, 2011 Grade 1.4162 Saint Fruitos, 2009 Grade 1.4162 Cala Galdana, 2005 Grade 1.4462 CRC = Corrosion Resistance Class (EN 1993-1-4 Annex A )

Klassningar CRC II, III CRC III CRC IV/V Low * (M > 10 km) Medium * (1 km < M 10 km) High* (0,25 km < M 1 km) Very high* (M 0,25 km) Orrhammarvägen Bridge Duplex grade 1.4162 6 years Añorga Bridge Duplex grade 1.4162 4 years Zumaia Bridge Duplex grade 1.4462 7 years Cala Galdana Duplex grade 1.4462 10 years Millenium Bridge Duplex grade 1.4462 15 years Puerto Arrupe Bridge Duplex grade 1.4362 12 years Risk of exposure to chlorides from sea salt water M=Distance from the sea Note: No information about cleaning and mainternance done was available. CRC = Corrosion Resistance Class (EN 1993-1-4 Annex A )

Sicklauddsbron Pedestrian Bridge General information: - Year constructed: 2002 Location: Sweden - ISO 9223 Class: C3 - Above channel, 255 ppm Cl - measured - Rain washed Materials: Forta DX 2205, beams, flange, handrail - Generally in good condition - Ra 4.0 µm 316L, end cover tube of bridge cables - Good condition, some staining due to contamination 304, brackets and stanchion - Overall in good condition but isolated pits can be observed This information is given in good faith and Outokumpu assume no liability for it 10/30/2017 39

Orrhammarvägen Bridge Location: Flen, Sweden Structure type: Road bridge Corrosion resistance class: CRC II, III Year of completion: 2009 (6 years) Distance from the salt water: ~60 km Local environmental notes: 8 ppm Cl- measured Longitudinal beam web Longitudinal beam flange Grade 1.4162 Longitudinal beam weld ER 23 7 NL Bridge bearing plate Grade 1.4162 Inspection date: 10/06/2015

Orrhammarvägen Bridge 1.4162 Sheltered condition Bridge beams (Ra~5.0 µm): General appearance is in good condition Sheltered condition Welded areas: Some accumulation of dirt/dust Sheltered condition Bottom of beam: Orange stain and contamination Small bolts: Poor condition. Galvanizing was visible on the bolt heads but not the shanks or nuts. Inspection date: 10/06/2015

Orrhammarvägen Bridge 1.4162 Bottom of beam: Orange stain and contamination from mild steel after the surface finishing was applied (No chloride ion was found). SEM/EDS-result Spectrum C O Mg Si K Ca Mn Fe Total Spectrum 1 6.97 42.7 1.72 2.54 0.78 0.72 44.5 100 Spectrum 2 8.31 40.6 2.42 2.57 0.93 0.67 0.68 43.9 100 Max. 8.31 42.7 2.42 2.57 0.93 0.67 0.72 44.5 Min. 6.97 40.6 1.72 2.54 0.78 0.67 0.68 43.9 Inspection date: 10/06/2015

Añorga Bridge Location: San Sebastian, Spain Structure type: Railway bridge Corrosion resistance class: CRC II, III Year of completion: 2011 (4 years) Distance from the salt water: ~ 3 km Handrail pole Handrail cable fitting Handrail tie plate Grade 1.4401 Arch transition structure top surface (Ra~6 µm) Grade 1.4301 Main arch Grade 1.4162 Arch transition structure side surface Grade 1.4162 Arch weld ER 23 7 NL Bridge beam (Ra~8 µm) Grade 1.4162 Inspection date: 20/10/2015

Añorga Bridge Main arch Arch weld 1.4162 1.4401 Handrail pole, cable fitting and tie plate 1.4401 Inspection date: 20/10/2015

Puerto Arrupe Bridge Location: Bilbao, Spain Structure type: Footbridge / Cycleway Corrosion resistance class: CRC II, III Year of completion: 2003 (12 years) Distance from the salt water: ~10 km Local environmental notes: 2,400 ppm Cl- measured Fin Weld Fin Handrail Bridge box side surface at stair Wood Fin Bridge box side surface Bridge box fin Grade 1.4362 Bridge box to fin weld ER 22 9 3NL Bridge box side surface at stair Grade 1.4362 Tubular handrail Grade 1.4401 Inspection date: 20/10/2015

Puerto Arrupe Bridge 1.4362 Open condition Sheltered condition Sheltered condition Bridge box side surface (Ra ~4 µm), welds and fin: Good condition Bridge box surface in sheltered area: Some accumulation of dirt and staining. Discoloration is likely due to no washing, fabrication or transportation. 1.4362 Bridge box side and fins: Orange stain Fabrication (grinding, spatter from welding). No chloride ion was observed at this point (SEM/EDS) Welds: Some scratch, dark spot from weld oxide and accumulation of dirt. Inspection date: 20/10/2015

Puerto Arrupe Bridge 1.4362 1.4362 Sheltered condition Bridge box fins under surface at stair: Orange staining and discoloration Bridge box fins (Ra 4 µm): Easy to trap water and some green organic matter was growing in this area. Internal side surface and bridge box side surface at stair: Color painting to covering all scratches, vandalism, accidental contact with bicycles, dog urine, etc., Inspection date: 20/10/2015

Millennium Bridge Location: York, UK Structure type: Pedestrian bridge Corrosion resistance class: CRC II, III Year constructed: 2000 (15 years) Distance from the salt water: ~60 km Local environmental notes: 20 ppm Cl- measured Bridge arch (Ra ~0.3 µm) 1.4462 Bridge deck kurb 1.4401 Balustrade handrail 1.4401 Inspection date: 17/08/2015 Balustrade infill framing 1.4301 Balustrade stanchion Painted carbon steel Handrail 1.4401 Cable fitting and bolt Suspension cable 1.4401

Millennium Bridge 1.4462 1.4462 1.4462 Open condition Sheltered condition Arch (Ra ~0.3 µm): Discoloration is more related to birds (some bird droppings) that evidently perch on the arch. No corrosion was observed. Junction between arch and deck: Stain was noted. 1.4401 1.4401 1.4401 1.4301 Cable: Good condition with some staining and debris were observed. Handrail design: Easy to trap water and some green organic matter was growing in this area. Mesh frame (Ra~ 0.3 µm) and Infill mesh: Good condition Inspection date: 17/08/2015

Millennium Bridge 1.4401 1.4401 1.4401 Handrail (circular section): Good condition Stanchions - vertical direction: Some staining Horizontal direction (Ra~2.5 µm): Some staining 1.4401 Painted carbon steel Fin at the northwestern side: Orange staining consistent with contamination from mild steel. No evidence of structurally concerning corrosion. Inspection date: 17/08/2015

Zumaia Bridge Location: Zumaia, Spain Structure type: Footbridge Corrosion resistance class: CRC III Year of completion: 2008 (7 years) Distance from the salt water: ~1 km Local environmental notes: 15,200 ppm Cl- measured Inspection date: 20/10/2015

Zumaia Bridge Fiber glass Handrail Wood Bridge beam (Deck facing surface) Grade 1.4462 Bridge beam Grade 1.4462 Checker plate flooring Grade 1.4301 Weld (Ra ~ 4 µm) Weld Balustrade top surface Grade 1.4462 Weld ER 22 9 3NL Balustrade infill bracket Grade 1.4462 Bolt head Grade 1.4401 Balustrade end plate Grade 1.4462 Weld ER 22 9 3NL Stiffening angle under handrail Grade 1.4462 Handrail extension plate Grade 1.4462 Inspection date: 20/10/2015

Zumaia footbridge 1.4462 1.4462 Bridge beam Bridge beam Bridge beam (Deck facing surface, Ra~4-5 µm) 1.4462 Weld Balustrade top surface (Ra~5-6 µm) Weld Weld General appearance to be in good condition. No chloride ion (SEM) was found on the surface. Staining and discoloration was observed on the surface. No corrosion attack were observed Inspection date: 20/10/2015

Zumaia footbridge 1.4462 Balustrade top surface and end plate: Orange stain Fabrication (grinding) of carbon steel fence (handrail) beside the bridge 1.4462 1.4401 Weld oxide and heat tints Orange stain on the dome nuts and under crevice area. Inspection date: 20/10/2015

Cala Galdana Bridge Location: Menorca, Spain Structure type: Road and foot bridge Corrosion resistance class: CRC IV/V Year of completion: 2005 (10 years) Distance from the salt water: < 250 m Local environmental notes: 17,300 ppm Cl- measured Inspection date: 22/10/2015

Cala Galdana Bridge Balustrade staunchion (Bracket plate and plate) Balustrade infill tube and hand rail Grade 1.4462 Bridge deck main beam Bridge deck outrigger beam Grade 1.4462 Main bridge arch weld ER 22 9 3NL Bridge arch Grade 1.4462 Bridge arch infill plate Grade 1.4462 Vehicle barrier to arch transition ER 19 12 3 L Bolt and nut Galvanized steel Vehicle barrier tube Bracket base plate Plate Grade 1.4401 Vehicle barrier bracket weld ER 22 9 3NL Inspection date: 22/10/2015

Cala Galdana Bridge Weld 1.4462 Infill plate (Ra ~4-5 µm) 1.4462 Weld Weld Main bridge arch, infill plate and weld: General appearance to be in good condition 1.4462 1.4462 Balustrades (Ra 3-6 µm): Grey staining and discoloration was observed on the surface. Inspection date: 22/10/2015

Cala Galdana Bridge 1.4462 Sheltered condition Sheltered condition Sheltered condition Bridge deck: Good condition. Staining from water run off 1.4401 1.4462 Fabrication: Some weld spatter was observed but did not cause any corrosion. 1.4462 Fabrication: Orange staining at creviced associated with weld joint between two tubes Bolt and nut: Red rust and corrosion Inspection date: 22/10/2015

Cala Galdana Bridge 1.4462 1.4401 Galvanized steel ER 19 12 3 L 1.4401 ER 22 9 3NL 1.4462 1.4401 Inspection date: 22/10/2015

Sölvesborg Pedestrian and Cycle Bridge General information: - Year constructed: 2013 Location: Sweden - ISO 9223 Class: C2 - Saline Bay, 3997 ppm Cl - in the water - Corrosion resistance class II or III in general depending on frequency of rain washing Materials: Forta LDX 2101 on arch - Generally in good condition - Ra 3.0 µm 316L hand rails, cable fittings - Some orange staining from contamination - Ra 3.0 µm This information is given in good faith and Outokumpu assume no liability for it 10/30/2017 60

Resultat Det allmänna intrycket från inspektionerna är att broarna är i generellt gott skick. De flesta anmärkningarna kommer från kontaminering, fabrikation, transport eller dagligt bruk. Fel: Kolstålsavskrap, kapskivesprut, svetssprut, dåligt betade svetsar, kolstålsskruvar, fel stålsort Inget som påverkar funktionen. Materialvalen som gjorts i dessa fall kan bedömas som rätt och överenstämmer i princip med Eurocodereglerna.

Tack för uppmärksamheten! 10/30/2017 62