Grain growth in Line Pipe Steels Solutions for critical materials under extreme conditions Grain growth in Line Pipe Steels Written by: Walter Antonio Tichauer Advisor: Ernst Gamsjäger, assoz.Prof. Dipl.-Ing. Dr.mont.

Contents -Pipelines for oil and gas transport Pipeline engineering What properties are we looking for? Do we REALLY need materials with higher material strengths? -In situ grain size measurements LUT HT-LSCM Average grain size & Distribution MEASUREMENTS RESULTS -Comparison of both techniques -Conclusions

Contents -Pipelines for oil and gas transport Pipeline engineering What properties are we looking for? Do we REALLY need materials with higher material strengths? -In situ grain size measurements LUT HT-LSCM Average grain size & Distribution MEASUREMENTS RESULTS -Comparison of both techniques -Conclusions

-Pipeline engineering Properties of different materials Machining of materials Microstructure-properties relationship Sc… Strength of the material SF… Safety factor L… Loads B… Back ups

-Pipeline engineering Properties of different materials Machining of materials Microstructure-properties relationship ΔT Gas composition Longitudinal ground profile Q → n → Dp

What properties are we looking for? PROPERTIES WE ARE LOOKING FOR: High ductility High strength Excellent weldability How can we achieve this? David and Goliath

Do we REALLY need materials with higher material strengths?

Do we REALLY need materials with higher material strengths? YES

Contents -Pipelines for oil and gas transport Pipeline engineering What properties are we looking for? Do we REALLY need materials with higher material strengths? -In situ grain size measurements LUT HT-LSCM Average grain size & Distribution MEASUREMENTS RESULTS -Comparison of both techniques -Conclusions

Contents -Pipelines for oil and gas transport Pipeline engineering What properties are we looking for? Do we REALLY need materials with higher material strengths? -In situ grain size measurements LUT HT-LSCM Average grain size & Distribution MEASUREMENTS RESULTS -Comparison of both techniques -Conclusions

Laser Ultrasonics Technique (LUT) [1] Provided by Professor Militzer M.

Contents -Pipelines for oil and gas transport Pipeline engineering What properties are we looking for? Do we REALLY need materials with higher material strengths? -In situ grain size measurements LUT HT-LSCM Average grain size & Distribution MEASUREMENTS RESULTS -Comparison of both techniques -Conclusions

High Temperature Laser Scanning Confocal Microscopy (HT-LSCM)

Video Grain growth

Average grain size & Grain size distribution MEASUREMENTS of a sample heated up to 1050 °C

Average grain size & Grain size distribution MEASUREMENTS of a sample heated up to 1150 °C

Average grain size & Grain size distribution MEASUREMENTS of a sample heated up to 1250 °C

Average grain size RESULTS Conditions to t1 Conditions to t2 Sample t1 [s] number of grains d [µm] t2 [s] 1050 °C 180.07 406 *14.4 242.78 337 17.4 1150 °C 94.84 267 21.6 257.28 *189 30.1 1250 °C  66.23 363 *15.8 270.91 *218 53.1 *[2]

Grain size distribution RESULTS of a sample heated up to 1050 °C

Grain size distribution RESULTS of a sample heated up to 1150 °C

Grain size distribution RESULTS of a sample heated up to 1250 °C

Contents -Pipelines for oil and gas transport Pipeline engineering What properties are we looking for? Do we REALLY need materials with higher material strengths? -In situ grain size measurements LUT HT-LSCM Average grain size & Distribution MEASUREMENTS RESULTS -Comparison of both techniques -Conclusions

Comparison of LUT and HT-LSCM average grain size measurements

Comparison of LUT and HT-LSCM average grain size measurements

Contents -Pipelines for oil and gas transport Pipeline engineering What properties are we looking for? Do we REALLY need materials with higher material strengths? -In situ grain size measurements LUT HT-LSCM Average grain size & Distribution MEASUREMENTS RESULTS -Comparison of both techniques -Conclusions

Conclusions -During phases of high DT changes, LUT complements HT-LSCM. -HT-LSCM will be REQUIRED if a multimodal distribution is expected if the grain size distribution is unknown

References [1] Militzer M, Maalekian M, Radis R, Poole W J, Moreau A. In situ measurement and modeling of austenite grain growth in a Ti/Nb microaalloyed steel 2014. Acta Materialia 60 (2012) 1015-1026. [2] ASTM International. Standard Test Methods for Determining Average Grain Size. E 112. [3] Takayama Y, Furushiro N, Tozawa T, Kato H, Hori S. Asignificant Method for Estimation of the Grain Size of Polycrystalline Materials. Materials Transaction, JIM, Vol. 32, No. 3 (1991).

Thank you very much for your attention! Questions?