XSTEELIA™ Catalyst for Steel Innovation
Steel for environmental load reduction-type bridge cables

Delivering products of the world’s highest strength with our original process (DLP).

In order to respond to customers' needs for long bridge projects, which are expanding all over the world, we have developed products with the world’s highest strength up to a 2.0GPa grade using our original process (DLP).

Product list

Strength
(GPa)
Wire
diameter
Standards Steel type Achievements
Category C% Mn%
1.7 5mm SWRS82B JIS steel 0.82 0.75 Circle
7mm SWRS82B 0.82 0.75 Circle
1.8 5mm S82BM Developed steel
(high silicon steel)
0.82 0.75 Circle
(Akashi Kaikyo Bridge)
7mm S87BM 0.87 0.75 Circle
1.9 5mm S87BM 0.87 0.75 Proposed in
7mm S92AM 0.92 0.45 Circle
(Hong Kong-Zhuhai-Macau Link Road)
2.0 5mm S87BM/S92AM 0.87/0.92 0.75/0.45 Proposed in
7mm S97AM 0.97 0.45 Proposed in

What is DLP (Direct in-Line Patenting)?

In-line heat treatment enables omission of the heat treatment (LP, lead patenting) process on the customer’s side. In addition, this enables manufacturing of a highly-balanced wire rod with strength, toughness and ductility using the method excellent in productivity and environmental response.

Wire rod manufacturing process (Nippon Steel) / Wire manufacturing process (customer)
Around 3,000 to 20,000 tons of wires are used per bridge.
 Hot rolling Cooling and heat treatment Heat treatment Wire drawing Hot dipping Conventional method Productivity with LP: 1,000t/month/factory CO2 Emissions:CO2100kg/t-steel Current development Productivity with DLP: 30,000t/month/factory(Improved 30 times over) CO2 emissions:CO2 30kg/t-steel(Reduced by 70%)

Contributes to the expansion of design flexibility, improvement of productivity and shortening of construction periods, and reduction of CO2 emissions.

Advantages from the current development technology

Applied technology Function and efficiency improved from the previous technology (LP) Conventional (LP method) Current (DLP™ method) DLP™[First in the world] 機能 (i)CO2排出量の削減 100KG/t-steel→30kg/t-steel(ii)鉛フリー化 Lead→Nitrate(iii)生産性向上 1,000t/month/factory→3,000t/month/factory(iv)LP規制地域での高強度ワイヤ製造 Difficult→Possible 性能(i)線材の太径化(ワイヤの太径化)→Improved design flexibility B,Ti添加【世界初】 性能 (ii)ワイヤの高強度化→Longer center span, reduction of construction costs (iii)冷却伸線技術などの簡略化→Easier manufacturing of wires

Advantages of high strength (cost and construction period)

Total weight of bridge steel (by wire strength)

Design example of the base of the Akashi Kaikyo Bridge Results Estimate Wire strength 1770MPa grade 1960 MPa grade Number of main cables 2 2 Number of strands 580 550 Cable weight 50,000t 45,000t Height of main tower 283m 283m Weight of main tower 49,000t 47,000t Weight of complimentary rigid beam 83,000t 83,000t Total weight of steel 182,000t 175,000t(-4%) Construction period 41 months 38 months(-3months)

Applied example

Hong Kong-Zhuhai-Macau Link Road

(1)Project name

Hong Kong-Zhuhai-Macau Link Road

A large project of road with a length of about 36km (China side: about 30km, Hong Kong side: about 6km) linking Hong Kong and Macau. The bridge part is 21.8km long and the cable stayed bridge part is 1.5km long.
The 1.2km high strength mono-strand cable (1. Jianghai Direct Vessel Navigation Bridge: one suspension, 77m, three-tower cable stayed bridge, 2. Qingzhou Vessel Navigation Bridge: two suspension, 458m, two-tower cable stayed bridge) was delivered. The entire project period lasted from October 2010 to the end of 2016, and the construction of the bridge part started in May 2011.

(2)Applied products wires for mono-strand cable for cable stayed bridge
[Standard: S92AM Wire diameter: Φ7mm Strength: 1.9GPa]
(3)Applied amount about 1,000 t
Bridge name Cable Type Tower Span
Jianghai Direct Vessel Navigation Bridge 7mm
1.9GPa grade
Three-tower cable stayed bridge
One suspension, Box Girder
Metal tower Total: 774 m
129m+258m+258m+129m
Qingzhou Vessel Navigation Bridge 7mm
1.9GPa grade
Two-tower cable stayed bridge
Two suspension, Box Girder
RC tower 458m

From Chinese capital section to Jiu Zhou Port Vessel Navigation Bridge / Jianghai Direct Vessel Navigation Bridge *Current development section (1) / Qingzhou Vessel Navigation Bridge *Current development section (2) / Hong Kong capital section

Past results

Suspension bridge (top 10 center spans and cases that applied our material)

Ranking Bridge name Center span/m Country Year of completion Application of Nippon Steel material
1 Akashi Kaikyo Bridge 1,991 Japan 1998 Circle
2 Zhoushan Xihoumen Bridge 1,650 China 2009 Circle
3 Great Belt East Bridge 1,624 Denmark 1998
4 Izmit Bay Bridge 1,550 Turkey 2016 Circle
5 Yi Sun-sin Bridge 1,545 South Korea 2013
6 Runyang Yangtze River Bridge 1,490 China 2005 Circle
7 Fourth Nanjing Yangtze Bridge 1,418 China 2012
8 Humber Bridge 1,410 England 1981
9 Third Bospolas Bridge 1,408 Turkey 2016 (scheduled)
10 Jiangyin Yangtze River Bridge 1,385 China 1999 Circle

Cable stayed bridge (top 10 center spans and cases that applied our material)

Ranking Bridge name Center span/m Country Year of completion Application of Nippon Steel material
1 Russky Bridge 1,104 Russia 2012 Circle
2 Sutong Yangtze River Bridge 1,088 China 2008
3 Stonecutters Bridge 1,018 China 2009 Circle
4 Edong Yangtze River Bridge 926 China 2010 Circle
5 Tatara Brige 890 Japan 1999 Circle
6 Normandy Bridge 856 France 1995
7 Jiujiang Yangtze River Bridge 818 China 2013
8 Jingyue Yangtze River Bridge 816 China 2010 Circle
9 Incheon Bridge 800 South Korea 2009 Circle
10 Zolotoy Bridge 737 Russia 2012