Mechanism of improved corrosion resistance of type 304l stainless steel, nitric acid grade, in nitric acid environments

1994 ◽  
Vol 3 (6) ◽  
pp. 699-705 ◽  
Author(s):  
V. Kain ◽  
S. S. Shinde ◽  
H. S. Gadiyar
2019 ◽  
Vol 66 (2) ◽  
pp. 149-158 ◽  
Author(s):  
Gopinath Shit ◽  
S. Ningshen

Purpose High corrosion resistance in different concentrations of nitric acid is essential for structural steels to be used for the aqueous reprocessing of spent nuclear fuels with high plutonium content. Design/methodology/approach In the present study, the corrosion resistance of type 304L stainless steel (SS) with modified composition was evaluated in different concentrations of nitric acid using surface analytical techniques, weight loss method and electrochemical measurements. Findings Weight loss measurement in boiling 65 per cent nitric acid showed a low corrosion rate value of about 0.2 mm/y (8 mpy) after 240 h exposure. Electrochemical measurements revealed the shift in open circuit potentials as well as corrosion potential toward more noble direction, and the results of electrochemical impedance spectroscopy studies indicated the reduction in the thickness and stability of the passive film with increasing concentration from 6 to 11.5 M nitric acid. Research limitations/implications The low corrosion rate observed for this steel is attributed to the higher content of Cr (19 per cent), Ni (10 per cent) and Si (0.3 per cent) and controlled minor alloying elements (S, P, B, C, etc.) in the alloy that contributed to improving the transpassive corrosion resistance and minimizing the intergranular corrosion attack. The X-ray photoelectron spectroscopic analysis revealed the composition of the passive films to be mainly of iron and chromium oxides. Practical implications Materials with lower corrosion rates are desirable for applications in nitric acid. Social implications The used of nitric acid creates a severe corrosive environment in chemical or aqueous nuclear reprocessing plants, and hence with a modified composition of type 304L SS resulting in minimizing failure of components are desirable for reducing cost and maintenance. Originality/value The present paper is an original work carried out by the authors on the corrosion resistance behaviors of composition modified AISI type 304L SS for nitric acid application. The effects of different nitric acid concentrations were compared to provide understanding on in applicability in boiling and high nitric acid concentrations.


Alloy Digest ◽  
2003 ◽  
Vol 52 (2) ◽  

Abstract Carpenter Project 70+ Type 304/304L is a modified version of Type 304/304L stainless steel with improved machinability when compared to conventional 304 (Alloy Digest SS-418, revised September 1997) and 304L (Alloy Digest SS-513, revised November 1997). The alloys are nonhardenable austenitic chromium-nickel steels and are good general-purpose materials for simple and complex parts. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-875. Producer or source: Carpenter Specialty Alloys.


Alloy Digest ◽  
1996 ◽  
Vol 45 (7) ◽  

Abstract Sandvik 3R12/4L7 is a composite tube consisting of type 304L stainless steel for corrosion resistance on the outside diameter and having carbon steel (A210 Gr. A1) as the inside component for both water wetted service and the design load. The major application is tubing to handle the corrosive conditions in black liquor recovery boilers. This datasheet provides information on composition, physical properties, microstructure as well as fatigue. It also includes information on forming, heat treating, and joining. Filing Code: SA-482. Producer or source: Sandvik.


Alloy Digest ◽  
1972 ◽  
Vol 21 (5) ◽  

Abstract SANDVIK 2RE10 is a high-chromium, high-nickel, extra-low-carbon austenitic stainless steel with high resistance to oxidizing media such as concentrated nitric acid, high resistance to intergranular corrosion and good structural stability. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-272. Producer or source: Sandvik. See also Alloy Digest SS-491, November 1987.


Alloy Digest ◽  
1975 ◽  
Vol 24 (8) ◽  

Abstract Type CB-30 is an iron-chromium alloy sufficiently high in chromium content to provide excellent resistance to corrosion by nitric acid, alkaline solutions and many organic chemicals. They alloy maintains an essentially ferritic structure. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-315. Producer or source: Stainless steel foundries.


Author(s):  
Sorush Niknamian

Nowadays, welding of dissimilar metals has become significant. In this process, a number of parameters including but not limited to type of electrode, amount of current, preheating temperature, and welding rate, that are essential to be taken into account. For welding of dissimilar metals, various methods are exploited including shielded metal arc welding (SMAW) and gas tungsten arc welding (GTAW). The stimulus for studying welding of 304L stainless steel to pure copper originates from difficulties in joining copper parts of           water-circulating molds to their steel part. In this study, the welding is performed on plates of steel and copper using SMAW, GTAW and combined SMAW+GTAW welding methods with    EL-CuMn2, ENiCrMo-6 and ER70S-4 electrodes. In order to investigate the microstructure and corrosion resistance behavior of welds, the samples were characterized using microstructural study and polarization test. It was observed that among all four welding methods, only combined SMAW+GTAW welding process resulted in successful joint between 304L stainless steel and copper. Both obtained joints possess suitable microstructure and corrosion resistance.


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