Influence of Silicon and Manganese on Corrosion Behavior of Austenitic Stainless Steels

CORROSION ◽  
1968 ◽  
Vol 24 (12) ◽  
pp. 393-402 ◽  
Author(s):  
B. E. WILDE ◽  
J. S. ARMIJO

Abstract The influence of silicon and manganese on the electrochemical and corrosion behavior of a high purity austenitic 14Cr/14Ni-balance Fe alloy has been studied. Over the composition range 50–41, 500 ppm Si, no effect was observed on the kinetics of the anodic or cathodic partial processes. Addition of manganese over the range 5–26,300 ppm accelerates the anodic dissolution kinetics in the active range of potentials and also the steady-state corrosion rate in 1N̄ H2SO4 due to its influence on the kinetics of the cathodic partial process. The nature of this effect is analyzed according to electrode kinetic concepts from which it is shown that manganese changes the value of the electrode process transmission coefficient. Alloys containing manganese and silicon over large concentration ranges are extremely resistant to stress corrosion cracking in boiling 42 w/o MgCl2.

Author(s):  
Ikuo Ioka ◽  
Jun Suzuki ◽  
Takafumi Motoka ◽  
Kiyoshi Kiuchi ◽  
Junpei Nakayama

An intergranular corrosion is observed in austenitic stainless steels exposed to high temperature, concentrated nitric acid (HNO3) solution with highly oxidizing ions. It is an important degradation mechanism of austenitic stainless steels for use in a nuclear fuel reprocessing plant. The intergranular corrosion is caused by the segregation of impurities to grain boundaries and the resultant formation of active sites. Extra High Purity (EHP™) austenitic stainless steel was developed with conducting the new multiple refined melting in order to suppress the total harmful impurities less than 100ppm. The intergranular corrosion behavior of EHP alloys with various impurities was examined in boiling HNO3 solution with highly oxidizing ions to find a correlation between the intergranular corrosion and the impurities of EHP alloys. A good correlation was confirmed between the degree of intergranular corrosion and the corrosion rate. The relationships between the corrosion rate and the impurities content of EHP alloys was determined using a multiple regression analysis. The influence on corrosion rate became small in order of B, P, Si, C, S and Mn. It was important to control B in intergranular corrosion behavior of EHP alloys.


1999 ◽  
Vol 48 (3) ◽  
pp. 169-175 ◽  
Author(s):  
Alberto A. Ono ◽  
Tadashi Shinohara ◽  
Shigeo Tsujikawa

CORROSION ◽  
1976 ◽  
Vol 32 (9) ◽  
pp. 353-357 ◽  
Author(s):  
RONALD B. DIEGLE ◽  
DAVID A. VERMILYEA

Abstract Straining electrode experiments were performed to investigate the nature of strain enhanced corrosion of iron in caustic electrolyte. The strain enhanced corrosion rate was generally linearly dependent on applied strain rate, and its potential dependence paralleled that of steady-state polarization behavior on non-straining electrodes. Data was presented as ratios, in which is the corrosion rate in cm/s and is the corresponding strain rate. This ratio, which was shown in a previously published theory to be numerically equal to the crack advance per film rupture event during film rupture SCC, depended on electrochemical variables such as electrolyte concentration and temperature in a manner similar to the kinetics of caustic cracking. Conditions which are known to be marginal in producing caustic cracking resulted in values for of about 10−7 cm, in excellent agreement with a previously developed theory. It was concluded that strain enhanced corrosion in this system results from repetitive film rupture and repair during straining.


2007 ◽  
Vol 561-565 ◽  
pp. 2275-2278 ◽  
Author(s):  
Maribel L. Saucedo-Muñoz ◽  
Victor M. Lopez-Hirata

Three types of austenitic stainless steels JK2, JJ1 and JN1 were isothermally aged at temperatures from 873 to 1173 K for 10 to 1000 minutes in order to study the microstructural evolution. In general, the kinetics of precipitation for JN1 steel was faster than that of JJ1 steel, because of its higher interstitial solute content. The TTP diagrams showed that the intergranular precipitation of M23C6 and M2N preceded to the intragranular precipitation of M2N and M2N and η phase in JN1 and JJ1 steels, respectively.


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