Korean High Performance Steel for Bridges (HSB)

Transcription

1 KoreaJapan Joint Workshop on Steel Bridges, May 31, 2008 Korean High Performance Steel for Bridges (HSB) Yoon, TaeYang Research Institute of Industrial Science & Technology 1 Korean High Performance Steel for Bridges Development of HSB Material Properties Registration in KS (Korean Standards) Revision of Bridge Design Code Application of HSB 2

2 Development of HSB Introduction of HSB HSB is Korean High Performance Steel for Bridges RIST was awarded the National Research center for developing high performance construction materials (Director Yoon, TaeYang) HSB was developed as Korean high performance steel for bridges Development of 500/600MPa high performance steel for bridges Develop application technology and design optimization using HSB Cooperative research among POSCO, Korean expressway corp., fabricators, designers and academia 3 Development of HSB Introduction of HSB Specifications of HSB are derived from VOC (Opinions of the steel users) Voices of various experts (designers, academia, fabricators of steel bridges) Require higher strength, higher toughness, and better weldability 600 Ts (MPa) Charpy Energy 27J SM520B 47J SM570 47J HSB Preheat Temp SM SM490 SM520 SM570 Test Temp Conventional Steels HSB < Strength > < Toughness > < Weldability > Process for Producing Steel: TMCP (ThermoMechanical Controlled Process) 4

3 Development of HSB Development Process Process RIST POSCO Participants/Institutes Fabricator Consultants 3 rd agency Spec. Setup VOC survey Required Spec. Spec. Setup Pilot Product Performance Test Pilot Product Weld Consumable Korea Development Corp. Weld Tests Korea Testing & Research Institute Performance Certification Verification of Test Results Mass Product Manufacturing Spec. User s Guide & Code KS Registration Br. Design Code 5 Development of HSB HSB Development Schedule Commercial Product Commercial Product W/600W Commercial Product HSB800 Pilot Product /600 Korean Standard (KS) /600 Br. Design code/spec. W/600W Korean Standard (KS) W: Weathering steel W/600W Br. Design Code/Spec 6

4 Material Properties of HSB HSB vs Conventional Steels Tensile Str. (MPa) 600 Tensile Str. (MPa) Yield Str. (MPa) SM570 Max Thick. 100mm 380 Yield Str. (MPa) SM520C Max Thick. 100mm Steel Making Period [day] mm 50 Preheating Temp. Steel Making Period [day] mm 50 Preheating Temp. 20 Test Temp. (Toughness) < vs SM570> 20 Test Temp. (Toughness) < vs SM520C> 7 Material Properties of HSB HSB vs HPS, BHS 500 Yield Str. (MPa) BHS500 (JP) HPS485W (US) Steel Making Period (day] Tensile Str. (MPa) (KR) mm Test Temp. (Toughness) 50 < vs HPS485W, BHS500> Max Thick. 100mm Preheating Temp. Steel Making Period (day] Yield Str. (MPa) HPS345W (US) 350 Tensile Str. (MPa) (KR) mm 20 Test Temp. (Toughness) < vs HPS345W> 50 Max Thick. 100mm Preheating Temp. Process for Producing Steel: TMCP for HSB, BHS Q&T for HPS 8

5 Material Properties of HSB High Strength and High Toughness TMCP High tensile strength, No reduction of strength for thick plates High Toughness Reduction of brittle fracture in low temperature, Improvement of coldformability < C eq vs Tensile strength > < Charpy Energy vs test temperature > 9 Material Properties of HSB Weldability Low P cm Low preheating temperature Low C eq Reduction of cold cracking Carbon(%) CE=C+(Mn+Si)/6+(Ni+Cu)/15+(Cr+Mo+V)/5 < P cm vs min preheating temperature > < C eq vs Carbon > 10

6 Material Properties of HSB Fatigue Performance HSB satisfies the fatigue design spec. for all thickness tested Stress range (MPa) Korean Design Spec lower limit lower limit lower limit lower limit 1 (cycles) Number of Cycles <Fatigue Test for welded plates> < SN curves of HSB> 11 Registration in KS (Korean Standards) KS D 3868 HSB was Registered in KS as Rolled Steels for Bridge Structures, Aug., 2007 Symbol of HSB Symbol L W L W Max Thickness 100mm Notes For Bridge Structures L : Low Temperature W : Weathering Resistance Chemical Composition of HSB Symbol C Si Mn P S Cu Cr Ni L W ~ ~ ~0.80 L W ~ ~ ~

7 Registration in KS (Korean Standards) C eq and P cm SM490 SM520 SM570 L L W W C eq (%) T 50mm T mm P cm (%) T 50mm T mm Registration in KS (Korean Standards) Mechanical Properties Symbol Yield Strength Tensile Strength Thickness(mm) Elongation % specimen L W 380 MPa 500 MPa T 16 T < T # 1A # 1A # 4 L W 450 MPa 600 MPa T 16 T < T # 5 # 5 # 4 Charpy Energy Symbol Test Temperature Charpy Energy Notes W W 5 47 J For ordinary temperature L L J For low temperature 14

8 Revision of Bridge Design Code Revision of Korean Bridge Design Code Currently being revised by the Ministry of Land, Transport and Maritime Affairs Addition of HSB Articles for : linear interpolation between SM520 and SM570(yield strength) Articles for : same process as SM570 (due to same yield strength) There is No Reduction of min. yield strength of HSB w.r.t. plate thickness Thickness (mm) SS SM SMA < SM < SM490Y SM520 SMA < < SM570 SMA < < Min Yp (MPa) Ts (MPa) ~ ~ ~ 610 (520 ~ 640 for SM520) 570 ~ 720 SM490CTMC SM520CTMC SM570TMC Thickness (mm) Min Yp (MPa) Ts (MPa) 490 ~ ~ ~ Revision of Bridge Design Code Toughness Requirement : Max. Allowable Thickness Based on temperature zone and toughness, max. allowable thickness of steel is given HSBL with high toughness has better quality than conventional steels

9 Application of HSB 13,700 tons of HSB is supplied for bridges (Jan. 2007~ Present) Type Project Supply(ton) Procurement office Supply Period Incheon Bridge 1,420 Hanjin Heavy Industries & Const Busan Subway line 3 4,362 Busan Transportation Corp ~ SeoulBusan KTX (141) 2,445 Korea Rail Network Authority ~7 Gyeongju City Detour 1,690 Busan MOCT ~8 South Gumi IC Ramp 1,117 Korea Expressway Corp PCT Bridge 665 Korea Expressway Corp IksanJangsu highway br. 370 Korea Expressway Corp Jinbuk Industrial Complex Br. 537 Masan City Others 57 Sampyo, Sambu Suncheon HaryongSangsam Project 1,013 Samhyun PF ~ Total 13, Application of HSB Benefits of HSB Safety HSB High Strength Application to Bridge Simple Structural Type Easy Fabrication Fabrication Low Maintenance Cost 18

10 Application of HSB Twin Hybrid Girder Bridge Design concept of hybrid girder bridges Using different grades of steel in a section Optimize design by utilizing full capacity of the section Lower construction cost (10%), girder height (30%), total steel weight (15%) Over design area in web Allow local yielding M y > M y(hybrid) Minimize over design f y Conventional Section f y f yf f yw f yw f yf Hybrid Section ksi ( ) ksi 70 ksi ( ) ksi or 70ksi ksi ksi 70 ksi 70 ksi 70 ksi Hybrid Plate Girder 19 Application of HSB Twin Hybrid Girder Bridge Codes / Design guide using high performance steel Fabrication guide for high performance steel Optimal Design of twin girders Type Flange Web SM Weight (ton) SM490 Total Weight (ton) Cost (KR$ 1,000,000) (100%) 230 (100%) (99%) 218 (95%) SM (98%) 211 (92%) SM (98%) 207 (90%) (L= m, H=2m, B=0.5m) t w =67mm t f =10mm t w =13mm t f =14mm t w = 8mm t f =83mm < Ultimate stress states > < Ilsan Bridge > 20

11 Application of HSB Steel Towers/Pylons of CableSupported Bridges Reduce total construction period by prefabrication Aesthetic (slim, colorful, complex shapes are possible) Better structural quality due to shop fabrication Design alternative from concrete to steel towers Applying HSB reduces fabrication costs of towers Suspension bridge (height=270m) Cablestayed bridge (height=48m) 21 Application of HSB PRECOM: Prestressed Composite Girder Steel girders take the selfweight of concrete before composite action 22

12 Application of HSB TUrnover Girder Preflexing or prestressing steel girders by using the selfweight of girder 23 Thank you RIST 24 Steel Structure Research Center