scholarly journals Effect of Local Segregation of Phosphorous on Intergranular Corrosion of Type 310 Stainless Steel in Boiling Nitric Acid

2014 ◽  
Vol 63 (3) ◽  
pp. 98-103 ◽  
Author(s):  
Atsushi Komatsu ◽  
Takafumi Motooka ◽  
Masashi Makino ◽  
Kimihiro Nogiwa ◽  
Fumiyoshi Ueno ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Nitric Acid ◽  
Intergranular Corrosion ◽  
310 Stainless Steel ◽  
Local Segregation

Corrosion of Non-Sensitized Austenitic Stainless Steels in Nitric Acid Environment: An Electrochemical Approach

2013 ◽  
Vol 794 ◽  
pp. 517-529 ◽  
Author(s):  
Vivekanand Kain ◽  
Shagufta Khan ◽  
A.V.R. Reddy ◽  
P.K. Wattal
Keyword(s):  
Stainless Steel ◽  
Nitric Acid ◽  
Acid Concentration ◽  
Process Parameters ◽  
Stainless Steels ◽  
Intergranular Corrosion ◽  
Corrosion Behaviour ◽  
Austenitic Stainless Steels ◽  
Potential Range ◽  
Uniform Corrosion

The austenitic stainless steels are used in nuclear spent fuel reprocessing and waste management plants and the process fluid is nitric acid at temperature up to boiling point. However incorporation of oxidizing ions e.g. fission products as well as corrosion products, in nitric acid stream make the environment highly corrosive to stainless steels. Present work aims to investigate role of process parameters and material parameters (composition and microstructure) on corrosion behaviour of stainless steels. The process parameters studied are temperature, acid concentration and oxidizing ions. It has been shown that the potential attained on stainless steel is a function of acid concentration and temperature and is further strongly affected by addition of oxidizing ions. This developed potential determines the corrosion behaviour of stainless steel. Increasing the temperature and concentration of nitric acid and concentration of oxidizing species increased the developed potential. Potentials were applied to types 304 L (nitric acid grade - NAG), 304 L (commercial purity) and 310 L stainless steels in boiling 6 M nitric acid for a period of 48 h. The corrosion rates measured in such experiments were plotted as a function of applied potential. The form of corrosion was established by microstructural examination. A clear demarcation was observed between uniform corrosion and intergranular corrosion at a potential of 960-980 mVSCE. Above this potential range corrosion rate increased exponentially and the form of corrosion is shown to be intergranular corrosion. Below this potential range, uniform and low rate of corrosion occurred. The influence of microstructure (step, dual and ditch) of type 304 L was also studied and is described in this paper.

The Effect of Trace Boron Element on Local Corrosion Resistance of Casted 0.04C-16Cr Ferritic Stainless Steel

2011 ◽  
Vol 415-417 ◽  
pp. 800-806 ◽  
Author(s):  
Tie Ming Guo ◽  
Ding Cang Zhang ◽  
Zhi Hui ◽  
Chang Song Han ◽  
Li Ming Zhao
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Nitric Acid ◽  
Corrosion Rate ◽  
Ferritic Stainless Steel ◽  
Pitting Corrosion ◽  
Intergranular Corrosion ◽  
Corrosion Potential ◽  
Chloride Ions ◽  
Curve Method

0.04C-16Cr and 0.04C-16Cr containing 26ppm B ferritic stainless steels were smelted by using a vacuum induction furnace. Then 65% boiling nitric acid method and the electrochemical potentiokinetic reactivation method (EPR) were used to research their intergranular corrosion sensitivity. Meanwhile, electrochemical test method (Tafel polarization curve method, the anode circular polarization curve method) and chemical immersion method were used to research their pitting corrosion resistance. The results showed that the corrosion rate of 0.04 C-16Cr stainless steel containing 26ppm B in 65% boiling nitric acid is lower than that of 0.04 C-16Cr stainless steel. The reactivation rate of 0.04C-16Cr containing 26ppm B in dilute sulphuric acid medium significantly reduced compared with that of 0.04C-16Cr. The pitting corrosion potential, self-corrosion potential and the value of (Eb-Ep) of the stainless steel containing with 26ppm B in chlorideions medium reduced, while the corrosion rate increased compared with the stainless steel without B addition. It indicates that trace boron addition improves the intergranular corrosion resistance and repair ability of the passive film of the 0.04C-16Cr ferritic stainless steel after pitting corrosion process in chloride ions medium, but it also promotes the pitting corrosion tendency of the steel. Besides, introduction B to 0.04C-16Cr ferritic stainless steel reduces the steel’s corrosion resistance in active dissolved zone and promotes its intergranular corrosion tendency in chloride ions medium. The electrochemical characteristics of local corrosion are consistent with the results of chemical immersion test.

Effect of Nitrogen Addition on the Intergranular Corrosion of 304L Stainless Steel in Nitric Acid Medium

CORROSION ◽  
10.5006/2283 ◽  
2017 ◽  
Vol 73 (6) ◽  
pp. 674-684
Author(s):  
A. Ravi Shankar ◽  
A. Vinod Kumar ◽  
R.P. George ◽  
U. Kamachi Mudali
Keyword(s):  
Stainless Steel ◽  
Nitric Acid ◽  
Acid Medium ◽  
Intergranular Corrosion ◽  
Nitrogen Addition ◽  
304L Stainless Steel ◽  
Nitric Acid Medium

Susceptibility of Intergranular Corrosion for Extra High Purity Austenitic Stainless Steel in Nitric Acid

2008 ◽  
Author(s):  
Ikuo Ioka ◽  
Chiaki Kato ◽  
Kiyoshi Kiuchi ◽  
Junpei Nakayama
Keyword(s):  
Stainless Steel ◽  
Nitric Acid ◽  
Austenitic Stainless Steel ◽  
High Purity ◽  
Intergranular Corrosion ◽  
Austenitic Stainless Steels ◽  
Intergranular Attack ◽  
Track Etching ◽  
Melting Technique ◽  
Superior Corrosion Resistance

Austenitic stainless steels suffer intergranular attack in boiling nitric acid with oxidants. The intergranular corrosion is mainly caused by the segregation of impurities to grain. An extra high purity austenitic stainless steel (EHP alloys) was developed with conducting the new multiple refined melting technique in order to suppress the total harmful impurities less than 100ppm. The basically corrosion behavior of type 310 EHP alloy with respect to nitric acid solution with highly oxidizing ions was investigated. The straining, aging and recrystallizing (SAR) treated type 310 EHP alloy showed superior corrosion resistance for intergranular attack. The segregated boron along the grain boundaries was one of main factor of intergranular corrosion from fission track etching results. The SAR treatment was effective to restrain the intergranular attack for type 310 EHP alloy with B less than 7ppm.

NiAl precipitation in Fe-12w/o Cr-5w/o Ni-4w/o Al

1983 ◽  
Vol 41 ◽  
pp. 202-203
Author(s):  
L.E. Murr ◽  
J.S. Dunning ◽  
S. Shankar
Keyword(s):  
Solid Solution ◽  
Stainless Steel ◽  
Stainless Steels ◽  
Alloy Composition ◽  
Chromium Content ◽  
Scale Up ◽  
Optical Metallography ◽  
Property Evaluation ◽  
310 Stainless Steel ◽  
Microstructural Studies

Aluminum additions to conventional 18Cr-8Ni austenitic stainless steel compositions impart excellent resistance to high sulfur environments. However, problems are typically encountered with aluminum additions above about 1% due to embrittlement caused by aluminum in solid solution and the precipitation of NiAl. Consequently, little use has been made of aluminum alloy additions to stainless steels for use in sulfur or H2S environments in the chemical industry, energy conversion or generation, and mineral processing, for example.A research program at the Albany Research Center has concentrated on the development of a wrought alloy composition with as low a chromium content as possible, with the idea of developing a low-chromium substitute for 310 stainless steel (25Cr-20Ni) which is often used in high-sulfur environments. On the basis of workability and microstructural studies involving optical metallography on 100g button ingots soaked at 700°C and air-cooled, a low-alloy composition Fe-12Cr-5Ni-4Al (in wt %) was selected for scale up and property evaluation.

NIROSTA 4429

Alloy Digest ◽  
2000 ◽  
Vol 49 (5) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Pitting Corrosion ◽  
Intergranular Corrosion ◽  
Heat Treating ◽  
Low Carbon ◽  
High Nitrogen ◽  
Temperature Performance ◽  
Pitting Corrosion Resistance

Abstract Nirosta 4429 is a low-carbon, high-nitrogen version of type 316 stainless steel. The low carbon imparts intergranular corrosion resistance while the nitrogen imparts both higher strength and some increased pitting corrosion resistance. It is recommended for use as welded parts that need not or cannot be annealed after welding. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-787. Producer or source: ThyssenKrupp Nirosta.

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