Speaker
Description
This work presents an investigation of pressure vessel steels P355NL2 and P460NL1 according to EN 10028-3. Heavy plates in the thickness range of 16-50 mm were rolled at NLMK DanSteel for CCS projects using controlled alloying, optimized rolling and heat treatment routes. P355NL2 was supplied in normalized condition (+N) and exhibits a homogeneous ferrite-pearlite microstructure ensuring strength and high low-temperature toughness. P460NL1 was produced in normalized rolled condition (+NR) and provided increased yield strength while maintaining sufficient toughness.
These steels represent two engineering approaches for pressure vessel construction: normalized plates with stable weldability and higher-strength plates allowing reduction of structural weight. For P355NL2, testing included plate-by-plate tensile tests, impact toughness at -50 °C and -45 °C, hardness measurements, and samples after simulated post-weld heat treatment (sPWHT). For P460NL1, testing included tensile tests, impact toughness testing at -20 °C and -40 °C, and hardness measurements. Weldability was evaluated on 37 mm P355NL2 plates welded with symmetric X-groove preparation by SAW process 121 LSO at 2.1 ± 0.1 kJ/mm, and on 34 mm P460NL1 plates welded with V-groove preparation by SAW process 121-2 at 1.5 ± 0.1 kJ/mm. Welded joints were characterized by macro- and microstructural analysis, hardness measurements, segmented impact toughness testing across weld zones, and, for P460NL1, CTS and BoP tests.
The results confirm that both steels meet EN 10028-3:2017 requirements and demonstrate stable mechanical properties and weldability for mobile CO₂ pressure vessels.
| Speaker Company/University | NLMK DanSteel |
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