Kawasaki Kanagawa, Japan
Kawasaki Kanagawa, Japan

Time filter

Source Type

Jachym R.,Instytut Spawalnictwa Institute of Welding | Lomozik M.,Instytut Spawalnictwa Institute of Welding | Kwiecinski K.,Instytut Spawalnictwa Institute of Welding | Urzynicok M.,ZELKOT Boiler Elements Factory | And 2 more authors.
ASM Proceedings of the International Conference: Trends in Welding Research | Year: 2013

Dynamic development of steels used in power engineering industry for the production of boilers characterised by supercritical parameters poses new welding challenges. The introduction of new combinations of alloying elements aimed at obtaining the best possible mechanical properties, including creep resistance, affects the weldability of new steels. Each of the latter must undergo many tests, particularly as regards bending and welding, in order to enable the development of technologies ensuring failure-free production and assembly of boiler systems. Martensitic steels containing 9% Cr, used in the manufacturing of steam superheaters, are characterised by good creep resistance and, at the same time, low oxidation resistance at a temperature in excess of 600°C. In turn, steels with a 12% Cr content are characterised by significantly higher oxidation resistance, but accompanied by lower strength at higher temperatures, which translates to their limited application in the production of boilers operating at the highest parameters. The niche between the aforesaid steels is perfectly filled by austenitic steels, the creep resistance and oxidation resistance of which are unquestionable. This article presents experience gained while welding similar joints of steel TEMPALOY A-3 and dissimilar joints of steels TEMPALOY A-3 and T91, with the use of EPRI87. The tests involving the said steel grades belong to the very few carried out in the world. Copyright © 2013 ASM International® All rights reserved.


Urzynicok M.,ZELKOT | Jachym R.,INSTITUTE of WELDING | Kwiecinski K.,INSTITUTE of WELDING | Mariani P.,Tenaris Group | Minami Y.,TenarisNKKTubes
Advances in Materials Technology for Fossil Power Plants - Proceedings from the 7th International Conference | Year: 2014

Dynamic development of steels used in power engineering industry for the production of boilers characterised by supercritical parameters poses new welding challenges. The introduction of new combinations of alloying agents aimed at obtaining the best possible mechanical properties, including creep resistance, affects the weldability of new steels. Each of the latter have to undergo many tests, particularly as regards bending and welding, in order to enable the development of technologies ensuring failure-free production and assembly of boiler systems. Martensitic steels containing 9% Cr, used in the manufacturing of steam superheaters, are characterised by good creep resistance and, at the same time, low oxidation resistance at a temperature in excess of 600°C. In turn, steels with a 12% Cr content are characterised by significantly higher oxidation resistance, but accompanied by lower strength at higher temperatures, which translates to their limited application in the production of boilers operating at the highest parameters. The niche between the aforesaid steels is perfectly filled by austenitic steels, the creep resistance and oxidation resistance of which are unquestionable. This article presents experience gained while welding dissimilar joints of advanced steels TEMPALOY AA-1 and T92, with the use of EPRI P87, Inconel 82 and Inconel 617 filler metals. The tests involving the said steel grades belong to the very few carried out in the world. Copyright © 2014 Electric Power Research Institute, Inc. Distributed by ASM International®. All rights reserved.


Hashizume S.,TenarisNKKTubes | Nakayama T.,Toshiba Corporation | Sakairi M.,Hokkaido University | Fushimi K.,Hokkaido University
Zairyo to Kankyo/ Corrosion Engineering | Year: 2011

Low Carbon-13%Cr martensitic stainless steels have been widely used for line pipe application because of their high strength and excellent corrosion resistance in corrosive conditions. Recently, both laboratory and field experiences related to cracking near fusion line of these steels weld joints in hot acid environments have been published. In this paper, SCC (Stress Corrosion Cracking) mechanism near fusion line of low C..13..Cr welded joints is discussed. Especially, initiation process is focused. Mainly electrochemical measurement using solution flow type micro-droplet cell and surface analysis of weld joints are conducted. In the evaluation of electrochemical behavior of low C-13%Cr welded joints with and without PWHT (Post Welded Heat Treatment) by the use of a solution flow type micro-droplet cell, PWHT leads to more noble and stable potential in HAZ (Heat Affected Zone) compared to as-welded condition. In the HAZ portion of the as-welded joint, Cr depleted layer was detected under welding scale with the use of GDS (Glow Discharge Spectrometer). PWHT was confirmed to eliminate Cr depleted layer under welding scale. This can be an initiation of SCC near girth welded joint in hot acid environment. Finally, mechanism of SCC initiation near fusion line of as-welded joint was proposed. Localized corrosionwould start at Cr depleted layer under welding oxide scale. This dissolution was also accelerated by a galvanic effect due to a large cathode area of base metal.


Hashizume S.,TenarisNKKTubes | Nishizawa N.,Waseda University | Yanagihara A.,Waseda University | Sakai J.,Waseda University
Materials Science and Technology Conference and Exhibition 2010, MS and T'10 | Year: 2010

Mo addition to martensitic stainless steels improves corrosion resistance of the steel in CO2 environments. This research was performed to clarify the role of Mo on 13%Cr steels in CO2 environments from the view points of corrosion film analysis by GDS. Mo enrichment was observed at outer layer in corrosion film of Mo additional steel when corrosion rate was small. This will lead to excellent corrosion resistance in CO2 environments. Copyright ©2010 MS&T'10®.


0.1C-18Cr-10Ni-3Cu-Ti-Nb steel (TEMPALOY AA-1; ASME C.C. 2512) shows allowable stresses 30% higher than those of ASME SA-213 Grade TP347H in the temperature range 600-700°C. This high creep rupture strength is obtained by the precipitation of MC and M23C6 carbides, and Cu-rich coherent phase. Long term creep rupture tests over 1.4·105h enabled to verify the superior creep rupture strength of this steel. The investigation of microstructural evolution on the creep ruptured and aged specimens has shown the high structural stability of this material. Excellent steam oxidation resistance is achieved by proprietary shot-blasting method. The yearly metal loss because of steam oxidation on shot-blasted tubes at 700°C is below 3 micrometers. These results have revealed that the mechanical properties and environmental resistance of this steel enable the use of TEMPALOY AA-1 in the latest generation of advanced USC boiler.


Caminada S.,Tenaris Group | Cumino G.,Tenaris Group | Cipolla L.,Centro Sviluppo Materiali S.p.A | Venditti D.,Centro Sviluppo Materiali S.p.A | And 3 more authors.
International Journal of Pressure Vessels and Piping | Year: 2010

The steam parameters in the new high efficiency fossil fuel power plants are continuously increasing, requiring new advanced materials with enhanced creep strength able to operate on the most severe temperature and pressure conditions. For super-heater and re-heater applications, TEMPALOY AA-1 steel, an evolution of 18Cr10NiNbTi alloy, has been developed through the addition of 3%Cu and B, significantly enhancing the creep resistance, while offering typical corrosion properties of 18%Cr steels. This paper describes Tenaris' tubular products in the field of austenitic grades for applications in Ultra Super Critical power plants: the production route and the main microstructural and mechanical properties of TEMPALOY AA-1 and TEMPALOY A-3 steels, including the effect of shot blasting on steam-oxidation resistance, their creep-rupture properties and their microstructural evolution during temperature exposure are presented. © 2010 Elsevier Ltd.


Hashizume S.,TenarisNKKTubes | Trillo E.,Southwest Research Institute | Kobayashi N.,TenarisNKKTubes
NACE - International Corrosion Conference Series | Year: 2013

Recently, CO2 has been highly pressurized in environments such as CO2 injection for stimulation and CO2 storage to reduce CO2 amount at surface. When CO2 is highly pressurized, a supercritical CO2 is created under conditions both over 31.1 degrees C and 72.9 atm. It is well known that water under pressurized CO2 gas leads to severe CO2 corrosion with carbon steel. Thus, CRAs are effective to prevent CO2 corrosion. In the supercritical CO2, corrosion behavior of carbon steel was reported. The corrosion rate of carbon steel was lower than the predicted model. From the view point of phase difference of CO2, the effect of CO2 in supercritical phase on CRAs is not clear. In this paper, the effect of CO2 in supercritical phase up to 300 bar on 13%Cr steels are examined. The effect of Oxygen on corrosion performance of 13%Cr steels under supercritical CO2 was also examined. The effect of supercritical CO2 on corrosion rate of 13%Cr steel was similar to or less than that of gas CO2. More than 200bar supercritical CO2 lead to localized corrosion. With 0.45bar Oxygen condition, crevice corrosion of 13%Cr steels in supercritical CO2 was recognized. Super-martensitic stainless steel showed better corrosion resistance than Type 420 in all conditions. ©2013 by NACE International.


Inoue T.,Japan Agency for Marine - Earth Science and Technology | Kyo M.,Japan Agency for Marine - Earth Science and Technology | Sakura K.,TenarisNKKTubes | Fukui T.,TenarisNKKTubes
Proceedings of the Annual Offshore Technology Conference | Year: 2014

The scientific drilling vessel Chikyu is performing challenging deep drilling activities, such as the Japan Trench Fast Drilling Program (JFAST), for conducting research on the Tohoku earthquake, which accompanied the tsunami that devastated northern Japan in March 2011. Generally, the fatigue strength of a drill pipe is a critical factor governing the performance of challenging deep drillings. This study therefore focused on the fatigue failure of a drill pipe, which is caused by an axial dynamic tension resulting from ship motion and drilling operation under the condition that a bending stress is exerted, in challenging deep drilling or drilling operations in harsh environments. Fatigue tests of actual drill pipes were conducted to acquire the actual fatigue curve. Further, the bending stress distribution of a drill pipe, which refers to the maximum locus of the bending stress during the drilling operation, was analyzed considering interference of the drill string with the structure or drilling equipment. The occurrence probability of ship inclination due to ship motions and ocean current, the occurrence probability of the bending stresses, and the axial dynamic stress and its occurrence probability were analyzed. Consequently, the cumulative damage ratio and the possible duration of operation were obtained. From the results, we confirmed how severe the deep drillings of JFAST are. Another important issue is to estimate the actual fatigue accumulated in drilling operations for further usage of the drill pipe. We therefore attempted to estimate the fatigue that accumulated during operations by using the abovementioned fatigue analysis along with drilling data acquired during the operation. Copyright 2014, Offshore Technology Conference.


Yoshida M.,TenarisNKKTubes | Takahashi S.,TenarisNKKTubes
Proceedings of the 10th International Conference on Technology of Plasticity, ICTP 2011 | Year: 2011

Generation criterion on thickness pulsation of seamless steel tubes in hot rolling process is analyzed by rolling experiments and 3-D FEM simulations. Double-thickness plate model is newly established to reproduce the thickness pulsation in the simple plate rolling process. The thickness pulsation was successfully reproduced by using the model in lead rolling experiments. As well as the results in previous studies, thickness pulsation appeared under the rolling conditions with high reduction ratio. FEM simulation performed for the experimented conditions. The thickness pulsation appeared when stress-strain curves with softening behavior in the material were examined in the simulations. Softening characteristic of the material is an indispensable factor to be considered in the generation criterion on thickness pulsation. © 2011 IBF (RWTH Aachen) & IUL (TU Dortmund).


Inoue T.,Japan Agency for Marine - Earth Science and Technology | Kyo M.,Japan Agency for Marine - Earth Science and Technology | Miyazaki T.,Japan Agency for Marine - Earth Science and Technology | Sakura K.,TenarisNKKTubes | Fukui T.,TenarisNKKTubes
Society of Petroleum Engineers - SPE International Conference and Exhibition on Oilfield Corrosion 2012 | Year: 2012

S150 drill pipe was developed during construction of the scientific drilling vessel Chikyu, and has been used in the past scientific drillings. On the other hand, during past drillings, Chikyu faced harsh environments such as a high-current or a corrosive environment in addition to deep drilling. To reach deep drilling in such a harsh environment, a higher strength and reliability drill pipe, as well as strength evaluation using the high-strength drill pipe, is necessary. Superior high-strength drill pipes, S155 and S160, possessing high reliability, such as corrosion resistance, have been developed. Pitting corrosion resistance, which causes stress concentration, is required to prevent fatigue failure. Also, consideration on possibility of SSC under low temperature at seabed is required because it would be a cause of fatigue. Regarding deep drilling and extended reach drilling, required feature is fatigue resistance of not only pipe body but also tool joints. In particular, the tool joint starts to become the cause of wearing out, mud pressure loss, mud bedding, heat cracking, and failure itself. The concept of the high-strength drill pipe, which we have developed, achieves high toughness and reduction of stress concentration along full string in the salt water to eliminate elements of fatigue phenomenon. The development includes the pipe manufacture process such as welding line performance, heat treatment methodology, the experimental investigation such as fatigue tests under salt water with or without pitting, and analytical investigation. The superior high-strength drill pipes described in the paper possess not only the high-strength performance but also high fatigue resistance in the corrosive environment. These can exercise the potential capability in the deep drillings, extended reach drillings, and harsh environment drillings. Copyright 2012, Society of Petroleum Engineers.

Loading TenarisNKKTubes collaborators
Loading TenarisNKKTubes collaborators