Sanmac 2205 long lifetime, low weight and ‘maintenance free’ duplex (austenitic-ferritic) stainless steel was chosen for critical ‘hanger’ components based on an entirely new hollow bar design.
The hangers will support a section of the 12km long high speed rail tunnel which includes the station. Inside the tunnel are two parallel tracks that will, in the future, enable two high-speed trains to pass each other at maximum speeds of 250kph.
The choice of duplex was specified by Ramboll, the engineering company for the project, after it was determined that the construction must remain maintenance free for 100 years. It is estimated that more than 4,000,000 movements will occur in the tunnel during that time. The railway is also the first of its kind to be situated inside a mountain, which places extra demands on the steel.
Viktor Stefansson, global product manager for hollow bar at Sandvik, said: “Sandvik Sanmac 2205 duplex stainless steel is a perfect grade where a material with high corrosion and fatigue resistance, and high mechanical strength, is required that could also provide excellent machinability. Duplex stainless steel is unbeatable if you need these properties.”
Construction on the Holmestrand station could only commence after the hangers – from which the rest of the structure is hung – were mounted. Sandvik helped control the logistic planning for the tunnel to a very tight schedule.
“When Sandvik came into the picture, they showed craftsmanship and were trustworthy, being the right partner,” said Jan Beckers, managing director of Hollandia, the company responsible for fabrication and erection of the steel. Construction company HENT has managed the overall station building project.
Support from Sandvik that was integral to the project included recommending improved dimensions for the Sanmac 2205 hanger components. This guaranteed optimal use of the material and saved Hollandia more than 100t of material. Sandvik was able to supply the components cut to length and on time according to a tight schedule.
Sandvik Materials Technology www.smt.sandvik.com
