Steel Division
Specializing in extreme conditions
Lowest arctic temperatures, highest pressure in the deep sea, acidic media: Even the most adverse conditions cannot harm our linepipe plates. Our plates can be found at depths of up to 3000 meters below sea level as sourgas-resistant linepipe plates or as land pipelines with a diameter of up to 48" (1220 mm). The highest sourgas requirements are met by our roll-bonded linepipe plates with corrosion-resistant cladding. As specialists in modern thermomechanical rolling processes with accelerated cooling, we are one of the world market leaders in linepipe plates. More than 2 million tons of sourgas-resistant linepipe plates and extremely tough linepipe plates for thick-walled deep-sea pipelines are ample proof of our product success.
Eddy current testing system successfully developed and approved
The oil and gas industry identified local hard zones (LHZ) as the root cause for Sulphide-Stress-Cracking (SSC) failures of carbon steel in severe sour service application representing zone 3 and beyond of the NACE diagram.
The characteristics of the local hard zones are that they reach hardness levels well above the typical base material hardness with a very low thickness (only several 0,1mm). The frequency of occurrence of such local hard zones is very low and random.
Demonstrating the absence of these local hard zones becomes one of the focal points of the industry. Based on the long lasting in-house experience for eddy current at voestalpine a highly automated testing system was developed and accredited by different oil and gas majors.
The magnetic field of the eddy current of the material represents material properties (magnetic hard vs. magnetic soft). A change of the material property caused by e.g. a local hard zone is detectable and can be identified.
At voestalpine the motorized equipment follows the plate surface by meander with an automated tracking. The coverage of the plate surface is 100% with an overlap from one track to the next. Due to the automated tracking an automated examination report with exact and automated localization of indications is created and recorded.
The Probability of detection (POD) based on different mathematical models and therefore the sensitivity of the system was demonstrated to different oil and gas majors. Additionally the best repeatability of detecting local hard zones were highlighted.
Voestalpine has a track record of more than 2,4 Mio tons of delivered plates for sour service application. For more than 340.000 tons of plates for commercially use for sour service (representing almost 15% of the delivered quantity) this highly automated testing system has been utilized.
Steel grades
Compliant with API 5L: | BM(S), X42M(S), X46M(S), X52M(S), X56M(S), X60M(S), X65M(S), X70M(S), X80M(S), X90M, X100M, X120M |
Pursuant to EN 10208-2: | L245MB, L360MB, L415MB, L450MB, L485MB, L555MB |
Pursuant to DNV GL: | SAWL245(S), SAWL290(S), SAWL320(S), SAWL360(S), SAWL390(S), SAWL415(S), SAWL450(S), SAWL485(S), SAWL555(S) |
Pursuant to GOST: | K56, K60, K65 |
pursuant to ISO 3138: | L245M(S), L290M(S), L320M(S), L360M(S), L390M(S), L415M(S), L450M(S), L458M(S), L555M, L625M, L690M, L830M |
Dimensions
Plate thickness: | 9.5-63 mm |
Plate width | 1400–3800 mm (48" pipe diameter max.), depending on steel grade and thickness, smaller widths upon request |
Plate length | 18,700 mm max.; dependent on thickness and steel grade |
Unit weight | 20.0 tons max. per unit |
Our linepipe plates are thermo-mechanically rolled and accelerated-cooled. All grades are available upon request in sourgas-resistant design at pH3 or pH5 pursuant to NACE TM 0284 Solution A and B. All steel grades are available with notched bar impact testing and Battelle testing (BDWTT) at temperatures below 0 °C. HIC tests for sourgas applications upon request.
