Corrosion Behavior of Duplex Stainless Steel in Industrial White Liquor

CORROSION ◽  
10.5006/2558 ◽  
2017 ◽  
Vol 74 (5) ◽  
pp. 543-550 ◽  
Author(s):  
Luiza Esteves ◽  
Mônica M.A.M. Schvartzman ◽  
Wagner Reis da Costa Campos ◽  
Vanessa F.C. Lins

Specimens of lean duplex and duplex stainless steel were exposed at 200°C in industrial white liquor from a Brazilian kraft mill using an autoclave to simulate the same conditions of digester processing. Tafel extrapolation method and weight loss were used to evaluate corrosion behavior of duplex steel in white liquor. The higher alloy steel, although presenting a lower corrosion rate than the lean duplex, presents a more severe selective attack on ferrite, at 200°C and 1.8 MPa, after Tafel extrapolation method in industrial white liquor.

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
G. Salinas ◽  
J. G. Gonzalez-Rodriguez ◽  
J. Porcayo-Calderon ◽  
V. M. Salinas-Bravo ◽  
M. A. Espinoza-Medina

The hot corrosion behavior of Fe40Al intermetallic alloyed with Ag, Cu, Li, and Ni (1–5 at.%) in NaCl-KCl (1 : 1 M) at 670°C, typical of waste gasification environments, has been evaluated by using polarization curves and weight loss techniques and compared with a 304-type stainless steel. Both gravimetric and electrochemical techniques showed that all different Fe40Al-base alloys have a much higher corrosion resistance than that for stainless steel. Among the different Fe40Al-based alloys, the corrosion rate was very similar among each other, but it was evident that the addition of Li decreased their corrosion rate whereas all the other elements increased it. Results have been explained in terms of the formation and stability of an external, protective Al2O3layer.


Author(s):  
Gina Genoveva ISTRATE ◽  
Alina Crina MUREȘAN

In this paper the corrosion behavior of different materials has been evaluated based on exposure in seawater. The laboratory immersion test technique has been applied to evaluate the effect of seawater on the corrosion behavior of different materials. In three sets of experiments, carbon steels (A681 Type O7), austenitic stainless steels (316L) and aluminium alloys (Al5083) were utilized. The specimens were fixed fully submerged in seawater. The corrosion process was evaluated using weight loss method, open-circuit potential measurements (OCP) and polarization techniques. To determine gravimetric index and the rate of penetration, samples were immersed in corrosive environment for 89 days and weighed periodically. The electrochemical experiments were conducted with a Potentiostat/Galvanostat (PGP 201) analyzer. It was connected to a PC. The Voltamaster software was used for electrochemical data analysis. A three-electrode cell composed of a specimen as a working electrode, Pt as counter electrode, and saturated calomel electrode (SCE) (Hg (l)/ Hg2Cl2 (s)) as a reference electrode were used for the tests. The weight loss tests revealed the lowest corrosion rate values for stainless steel and aluminium alloys, indicating a beneficial use for these materials in marine environments. The potentiodynamic method shows that the lowest corrosion rate in seawater (2.8 μm /year) was obtained for the Al5083 alloy, and the highest value of the corrosion rate (41.67 μm/year) for A681 carbon steel.


2014 ◽  
Vol 556-562 ◽  
pp. 162-165 ◽  
Author(s):  
Shi Dong Zhu ◽  
Hai Xia Ma ◽  
Jin Ling Li ◽  
Zhi Gang Yang

Effects of elemental sulfur on corrosion behavior of super 13Cr martensitic stainless steel were investigated by utilizing weight loss test, and the micro morphologies and chemical elements of corrosion scales were characterized by using SEM and EDS. The results showed that corrosion resistance of super 13Cr stainless steel was aggravated by the hydrolytic action of sulfur, the corrosion rate of super 13Cr stainless steel increased with the increasing of sulfur content, and firstly increased and then decreased with the increasing of temperature due to the activated adsorption and existential state of sulfur at the different temperatures.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fang Ge ◽  
Xiaojie Wang ◽  
Xinjing Meng ◽  
Xin Huang ◽  
Yi Zhang ◽  
...  

Abstract The corrosion behavior of duplex stainless steel 2205 DSS and 2507 DSS in simulated flue gas condensate of a waste incineration power plant at 180 °C was compared by micro-area electrochemical testing, surface and weight loss analysis. The results showed that the corrosion resistance of the two stainless steels decreased with the increase of Cl− concentration. After 48 h of corrosion, when the Cl− concentration was not less than 6 g·L−1, active sites where current density increased suddenly appeared on the surface of 2205 DSS, accompanied by the obvious increase of surface roughness and the weight loss. The lowest Cl− concentration that caused the appearance of active sites on the surface of 2507 DSS was 20 g·L−1, with less surface corrosion products and lower degree of general corrosion.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
S. Vuelvas-Rayo ◽  
J. G. Gonzalez-Rodriguez ◽  
J. Porcayo-Calderon ◽  
V. M. Salinas-Bravo ◽  
S. I. Maldonado-Ruiz

A study on the corrosion behavior of a series of experimental high-chromium (18.53–30.48 wt.%), high-carbon (3.82–5.17%) cast irons in NaCl-KCl (1 : 1 M) at 670°C has been evaluated by using weight loss technique and compared with a 304-type stainless steel. It was found that all castings had a higher corrosion rate than conventional 304SS and that the addition of Cr increased the degradation rate of the cast irons. Additionally, corrosion rate increased by increasing the C contents up to 4.29%, but it decreased with a further increase in its contents. Results are discussed in terms of consumption of the Cr2O3layer by the melt.


2021 ◽  
Vol 63 (6) ◽  
pp. 505-511
Author(s):  
Songkran Vongsilathai ◽  
Anchaleeporn Waritswat Lothongkum ◽  
Gobboon Lothongkum

Abstract A new duplex 25Cr-3Ni-7Mn-0.66 N alloy was prepared in a vacuum arc re-melting furnace and characterized by metallographic and EPMA methods. Its corrosion behavior was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and a Mott-Schottky (M-S) analysis in artificial seawater at room temperature and compared with those of super and normal commercial duplex stainless steel (SDSS and DSS). No significant difference in the open circuit potentials and pitting potentials was observed. Its passive film current density lies between those of SDSS and DSS. This was confirmed by EIS analysis. A pit attack was observed on the δ-phase for all duplex samples, because the PREN16 of the δ-phase was lower than that of the γ-phase. From the Mott-Schottky analysis, the passive films were found to be composed of bi-layer structures, a p-type semiconductor inner layer, and a n-type semiconductor outer layer. The degree of defect as well as the effect of nitrogen in passive film layer are discussed with respect to the point defect model.


2019 ◽  
Vol 22 (suppl 1) ◽  
Author(s):  
Stephania Cappellari de Rezende ◽  
Isabela Dainezi ◽  
Raíra Chefer Apolinario ◽  
Lucíola Lucena de Sousa ◽  
Neide Aparecida Mariano

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chuanbo Zheng ◽  
Cheng Zhang ◽  
Xiao Yong Wang ◽  
Jie Gu

Purpose Duplex stainless steel is composed of equal amounts of austenite and ferrite, which has excellent corrosion resistance and strength. However, after the metal was welded, the ratio of austenite and ferrite in the joint is unbalanced, and secondary phase precipitates are produced, which is also an important cause of pitting corrosion in the joint. Design/methodology/approach This paper aims to study the mechanical and corrosion behavior of welded joints, by adjusting the welding parameters of laser hybrid welding, dual heat sources are used to weld 2205 duplex stainless steel. The two-phase content of different parts of the welded joint is measured to study the influence of the ratio of the two-phase on the mechanical and corrosion properties of the joint. Findings The ratio of austenite and ferrite in different welded joints has an obvious difference, and from top to bottom, the austenite content decreased gradually, and the ferrite content increased gradually. The harmful phases are precipitated in the middle and lower part of the joint. The strength of welded joints is slightly lower than that of base metal. At the same time, the fracture analysis shows that some ferrite phases are affected by the precipitate in the grain and produce quasi-cleavage fracture. The corrosion results show that the corrosion resistance of the welded joints is lower than that of the base metal, and the concentration of chloride ions affects the corrosion resistance. Originality/value In this paper, the authors use the influence of different welding processes on the two-phase ratio of the joint to further study the influence of the microstructure on the corrosion resistance and mechanical properties of the weld.


2021 ◽  
Author(s):  
M. Helmi Nordin ◽  
M. Wahidullah Moh Wahi ◽  
Amresh Sashidharan ◽  
Nurfuzaini A. Karim ◽  
Alif Syahrizad Ramli

Abstract K field is a green field in East Malaysia with prolific gas reserves that is being developed with six high rate gas producing wells from high temperature (190 °C) carbonate reservoir. Tubular material feasibility study is one of the key subjects of scrutiny when it comes to completing wells in high temperature environment coupled with existence of significant level of H2S and CO2 contents. Material testing was conducted at the specified test environments (102 bar CO2 + 120ppm H2S) and load cases to assess susceptibility of Martensitic Stainless Steel to Stress Corrosion Cracking (SCC), corrosion rate and compatibility with completion brine. The aim was to optimize the material selection that is fit for purpose (lower completion and flow-wetted area of production casing) and reduce well cost up to USD 2.5 million. The base case of material selection for flow-wetted section is 17CR110 ksi, which meets the design requirements of these wells based on fit for purpose test conducted in the data base. Flow-wetted section in this case is production liner and flow-wetted section of production casing below production packer. Super 13CR -110 ksi and 15CR125 ksi material grades were considered for design optimization for this section of interest. Four Point Bend Method was used for SCC test sets while weight loss method for corrosion rate measurement. For brine compatibility test, calcium bromide (without additive) was used as test solution for 17CR 110 ksi, 15CR 125 ksi and Super 13CR -110 ksi with elevated temperature of 190 °C. Post-test assessment was conducted by visual examination by stereomicroscope to check for surface indication and dye-penetrant examination to determine any indication of cracks. It was observed that the Super 13CR -110 ksi and 15CR 125 ksi test specimens survived the test with no pitting observed. Meanwhile, test specimens were weighed to determine corrosion rates, resulted to Super 13CR -110 ksi sample having an average corrosion rate of 0.2195 mm/year. This translates to less than 30% weight loss throughout well production life and therefore accepted for open-hole production liner and production casing flow-wetted section. Key enabler in this design optimization effort is the understanding of the Stress Corrosion Cracking for martensitic stainless steel in high temperature sour environment where commonly, martensitic stainless steel (Super 13Cr / Modified Super 13Cr) working temperature is 165 °C. The test manages to extend the working temperature up to 190 °C.


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