Failure of Standard Duplex Stainless Steel X2CrNiMoN22-5-3 under Corrosion Fatigue in Geothermal Environment: A Recent Study | Chapter 6 | Recent Trends in Chemical and Material Sciences Vol. 4

 Corrosion fatigue has long been known to reduce the lifetime of high alloyed steels. X2CrNiMoN22-5-3 duplex stainless steel is a viable candidate for corrosion and mechanical stress resistance. As a result, the corrosion fatigue (CF) of the Northern German Basin electrolyte at 369 K was examined using a specially built corrosion chamber. The lateral grain attack within corrosion pit chambers placed perpendicular to the strain applied was clearly linked to CF damage. Multiple fatigue cracks, as well as favoured austenitic phase degeneration and intact ferritic phase. Fracture termination with little to no base metal deterioration is characterised by a delta-like micro crack structure and a curved course. The cavity in the immediate subsurface zone is most likely related to the first crack cavity with significant austenitic phase deterioration. Crack initiation can occur as a result of early pit development followed by depassivation, or as a result of local depassivation followed by pit formation — both mechanisms result in crack propagation and early failure.

Author(S) Details

Marcus Wolf
Department of Mechanical Engineering, Applied University of Berlin HTW, Berlin, Germany. and Federal Institute of Materials Research and Testing BAM, Berlin, Germany.

Anja Pfennig
Department of Mechanical Engineering, Applied University of Berlin HTW, Berlin, Germany.

View Book:- https://stm.bookpi.org/RTCAMS-V4/article/view/4798

Stress Corrosion Cracking of Lean Duplex Steel in 3.5% Sodium Chloride Solution | Chapter 2 | Recent Trends in Chemical and Material Sciences Vol. 1

 Duplex stainless steels (DSS) offer a desirable combination of austenitic and ferritic characteristics and are widely utilised in petrochemical, pulp and paper, and other industries. They outperform standard austenitic stainless steels in terms of corrosion resistance, particularly chloride stress corrosion and chloride pitting corrosion, as well as strength. They are a good contender for the offshore oil and gas industry because of these factors. Weight loss measurements, electrochemical corrosion tests, and a slow strain rate test were used to explore the stress corrosion behaviour of duplex stainless steel in a 3.5 percent sodium chloride solution in this work (SSRT). After 1700 hours of weight reduction, there was no substantial corrosion. In a 3.5 percent NaCl solution, an electrochemical polarisation test revealed a consistent corrosion rate of 0.008 mpy and passivity in the range of 735–950 mV Vs SSC. In a 3.5 percent NaCl solution, a comparison of the slow strain rate test for duplex stainless steel revealed a similar stress-strain behaviour. The stress-strain behaviour of mild steel, on the other hand, exhibited a loss of roughly 25% elongation. The excellent corrosion and, in particular, pitting resistance of DSS was thought to be responsible for its ductility.

Author (s) Details

Muhammad Shahid
School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad, Pakistan.

Ammer K. Jadoon
British Petroleum Ltd, UK.

Qanita Tayyaba
School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad, Pakistan.

Hina Farooq
School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad, Pakistan.

View Book :- https://stm.bookpi.org/RTCAMS-V1/article/view/2179

Influence of Geothermal Environment on the Corrosion Fatigue Behaviour of Standard Duplex Stainless Steel X2CrNiMoN22-5-3 | Chapter 12 | New Approaches in Engineering Research Vol. 2

 High alloyed steels' lifetime expectancy may be drastically reduced in geothermal environments due to corrosion fatigue. Using a specially built corrosion chamber, the corrosion fatigue (CF) of duplex stainless steel X2CrNiMoN22-5-3 was examined in the Northern German Basin electrolyte at 369 K. Despite the fact that the failure mechanism is unaffected by surface roughness (low scatter ranges technical surface: TN=1:1.35, polished surface: TN=1.1.95), the life expectancy in a simply alternating axial cyclic load to failure was clearly related to surface finish and applied stress amplitude. Specimens with technical surfaces persisted longer (cycles to f) when evaluated at high stress amplitudes (>275 MPa). specimens with polished surfaces (cycles to failure: P50 percent at Sa 300 MPa=1.5x105) than specimens with polished surfaces (cycles to failure: P50 percent at Sa 300 MPa=5x105). When a protective potential was applied, the CF life range increased significantly from 4.7 x 105 (free corrosion potential) to 107 cycles (potential range from USHE = –450 to –900 mV). Horizontal grain attack within corrosion pit cavities, many fatigue cracks, and preferred austenitic phase degeneration were shown by microstructural investigation of the CF damage. Pitting initiates fracture growth at low stress amplitudes, whereas the production of micro cracks causes crack propagation and failure at large stress amplitudes.

 
Author (s) Details

Marcus Wolf
HTW University of Applied Sciences Berlin, 12459 Berlin, Germany and BAM Federal Institute for Materials Research and Testing, Berlin, Germany.

Anja Pfennig
HTW University of Applied Sciences Berlin, 12459 Berlin, Germany.

View Book :- https://stm.bookpi.org/NAER-V2/article/view/2126

Understanding the Basic Metallurgy of Duplex Stainless Steel | Chapter 4 | Current Perspectives on Chemical Sciences Vol. 9

To understand the phase stability of ferrite at such elevated temperatures, duplex stainless steels with varying chromium content are taken and heat treated between the temperatures of 900 and 1000°C. Since the austenite grains remain unchanged after heat treatment, ferrite is the active step in duplex stainless steel. In addition, even though austenite is present in large amounts, the formation of sigma in ferrite phases affects the hardness of the material. It's also been discovered that the higher the ageing temperature, the faster the development of the sigma process in duplex stainless steel. Mo, in addition to Cr, increases the affinity for sigma phase formation.

Author (s) Details

Adhitya Karivaratharajan
Peekay Steel Castings Pvt Ltd, Kozhikode, Kerala, India.

Thillairajan Kuppusamy
PSG College of Technology, Coimbatore, Tamil Nadu, India.

View Book :- https://stm.bookpi.org/CPCS-V9/issue/view/44