JFE技報　No.5　厚板特集号

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1 JFE No Minimum Maintenance Steel Plates and Their Application Technologies for Bridge Life-Cycle-Cost Reduction Technologies with Environmental Safeguards for Preser ving Social Infrastructure Asset MAT JFE JFE KAWABAT JFE LCC Ni JFE LCC Ni 2 1.5Ni-.3Mo JFE-ACL Type1 C-2.5Ni JFE-ACL Type2 1 M JFE Cr Pb 1 Abstract: JFE Steel s life cycle cost reduction technologies with environmental safeguard for bridges are reviewed. As for weathering steel, two kinds of advanced steel of Ni type are lined-up for various airborne salt environments. JFE Steel has also developed a new software, which estimates the thickness loss of the weathering steel by atmospheric corrosion for its life time. By using this software, the most suitable weathering steel can be selected for a certain bridge location. The new surface treatment technologies that promote protective rust formation while keeping the good appearance of bridges were also developed. Furthermore, a pre-coat system to reduce the coating cost of bridge was developed ) 1 LCC Ni 2) LCC JFE Ni JIS SMA Ni 31

2 LCC JIS SMA Ni 2.1 LCC Fig. 1 3 LCC JIS SM ).5 mddnac mg/dm 2 /day JIS SMA 2.2Ni.5 mdd )) 6) Ni JFE-ACL Type1 5) JFE-ACL Typ JIS G 3114SMA.5 mdd Ni LCC Fig. 2 3) Ni JIS SMA Table 1 Ni 1.5Ni-.3Mo JFE-ACL Type1 Ni Mo Ni MoO4 2 C- 2.5Ni JFE-ACL Type2 Ni Fig. 3 6) JIS Z 3115JIS Z 311 C 275 LCC (yen/m 2 ) Phthalic resin paint (A-1) Polyurethane resin paint (C-2) Fluoro resin paint (C-4) JIS SMA LCC (yen/m 2 ) Polyurethane resin paint (C-1) Fluoro resin paint (C-4) Ni added weathering steel Time (year) Fig. 1 Comparison of life cycle cost (LCC) of bridges with several sur face treatment less than.5 mdd environment 3) Time (year) Fig. 2 Comparison of life cycle cost (LCC) of bridges with several surface treatment more than.5 mdd environment 3) JFE No

3 Table 1 Chemical compositions of Ni added weathering steels Steel JFE-ACL4 Type1 JFE-ACL49 Type1 JFE-ACL57 Type1 JFE-ACL4 Type2 JFE-ACL49 Type2 JFE-ACL57 Type2 Thickness (mm) C Si Mn Chemical composition (mass%) P S Cu Ni Mo.3.31 C eq * P CM * YS (N/mm 2 ) Mechanical properties TS (N/mm 2 ) * 1 C eq C Mn/6 Si/24 Ni/4 Cr/5 Mo/4 V/14, * 2 P CM C Si/3 Mn/2 Cu/2 6/Ni Cr/2 Mo/15 V/1 5B, * 3 ACL4 Type1, ACL49 Type1, ACL4 Type2, ACL4 Type2, ACL49 Type2, * 4 ACL57 Type1, ACL57 Type El (%) VEV * 3, VE (J) V 5* 4, VT S ( C) Maximum hardness, HV (98 v) Ni JIS SMA.5 mdd 1.5 mm 7) 1 8) 1 9) Open mark: Q-T steel Solid mark: Extremely-low carbon bainitic steel Test procedure; JIS Z 3115 JIS Z 311 Arc time: 12 s JFE-ACL Type2 Y AX B X Y mm AB JFE-ACL Type2 Conventional weathering steel P CM (%) Fig. 3 Relation between PCMC and maximum HAZ hardness of 57 MPa grade weathering steel subjected to arc strike welding 5).37 mdd.46 mdd Ni Type1 JFE-ACL Type2 1 1 Fig. 4.4 mdd JFE-ACL Type1.6 mdd JFE-ACL Type ) C C1r.6 C C1 1 km r 2.4 mdd JIS SM The Sea of Japan Coast (North side) The Pacific Coast Amount of air born salt (mdd) 2 k 5 k 2 k JFE-ACL Type1 JIS SMA JFE-ACL Type2 1 k 1 The distance from the coast (m) Fig. 4 Applicable area of Ni added weathering steels for coastal use JFE No

(JFE-ACL Type1) Photo 2 Appearance of Shinkouji-oohashi Bridge made of Ni added

5 95 mdd Photo 1 JFE-ACL Type1 1999 2 km Photo 2 JFE-ACL Type2 2 23 km LCC 2.

5 16 C 2 σ JIS SMANi JFE-ACL Type1JFE-ACL Type2 Address Distance from the coast

4 3. LCC 1) Photo 1 Appearance of Shigemisawa-bashi Bridge made of Ni added weathering steel (JFE-ACL Type1) Photo 2 Appearance of Shinkouji-oohashi Bridge made of Ni added weathering steel (JFE-ACL Type2).5 95 mdd Photo 1 JFE-ACL Type km Photo 2 JFE-ACL Type km LCC ) Fig C 2 σ JIS SMANi JFE-ACL Type1JFE-ACL Type2 Address Distance from the coast Parameters Temperature Humidity Air born salt Y AX B A f (T, H, P w, S a ) B f (A) Coefficient α, Corrosion loss σ σ σ 2σ Year Corrosion loss -year curve Input data Determination Calculation Exhibition Fig. 5 Flow chart of JFE Steel s corrosion estimation system JFE No

6 JIS SMA JFE-ACL Type1 LCC 3.2 22 12) 44 1 CrPb 3 M 13) 14) M Ni 3.2.1 M M 7 2 15) Photo 3 M M 2 2 16) M Cupten coat/ JFE-ACL Type1 3.

5 (a) JIS SMA (b) JFE-ACL Type1 Fig. 6 Calculated curve obtained by JFE Steel s corrosion estimation system 1 Fig. 6 JIS SMA JFE-ACL Type1 LCC ) 44 1 CrPb 3 M 13) 14) M Ni M M ) Photo 3 M M ) M Cupten coat/ JFE-ACL Type Cupten coat M/ JFE-ACL Type1 Photo 3 Appearance of mock-up bridge treated by Cupten coat and Cupten coat M after 3 year-exposure in coastal area 35 JFE No

After 3 years 6 mm After removing the coating Fig.

board after 3 year-exposure in coastal area Photo 4 3.2.3 M Fig.

8 Example of cost composition for conventional coating system Conventional coating system Sa2.

Appearance of World-cup-kyo Bridge applied with Cupten coat M treatment and pre-coat system (Yokohama

6 After 3 years 6 mm After removing the coating Fig. 8 Photo 56 M LCC Photo 4 Appearance of mock-up bridge treated by e-rus and rust outfl ow on plaster board after 3 year-exposure in coastal area Photo M Fig % Coating materials 25% Others 6% Painting Surface preparation 45% Fig. 8 Example of cost composition for conventional coating system Conventional coating system Sa2.5 or as scale Rust Pre-coat system Lower layer 15 µm For temporary corrosion protection Photo 5 Appearance of World-cup-kyo Bridge applied with Cupten coat M treatment and pre-coat system (Yokohama City) Manufacturing Blast Sa2.5 Repairing Top coating Fig. 7 Field/Touch up Pre-coat system of new surface treatment Photo 6 Appearance of Maruyama-bashi Bridge applied with e-rus treatment and pre-coat system (Okaya City) JFE No

7 4. Ni JIS SMA.5 mdd LCC JFE LCC v 22p vol vol. 3 p IV2 13 MNKK no. 171 p e-rus vol. 35no p II XX 5 no. 1712p. 37 JFE No

渡辺(2309)_渡辺(2309)

渡辺(2309)_渡辺(2309) [ 29 p. 241-247 (2011)] ** *** ** ** Development of a nickel-based filler metal containing a small amount of silicon by WATANABE Takehiko, WAKATSUKI Ken, YANAGISAWA Atsusi and SASAKI Tomohiro Authors tried

JFE技報 No.5 厚板特集号

JFE技報　No.5　厚板特集号