Comparative Corrosion Evaluation of Ferritic Stainless Steels Utilized in Automotive Exhaust Applications

2018 ◽  
Author(s):  
Yoel Emun ◽  
Guangchun Quan ◽  
Joseph Kish ◽  
Hatem Zurob
CORROSION ◽  
10.5006/3319 ◽  
2019 ◽  
Vol 75 (11) ◽  
pp. 1276-1280
Author(s):  
Y. Emun ◽  
H.S. Zurob ◽  
J.R. Kish

This study compares the localized (exterior) corrosion susceptibility of chromized steel to bench-mark ferritic stainless steels for automotive exhaust applications. Continuous near-neutral salt fog exposure (ASTM B117) was used for this purpose. Corrosion susceptibility was determined using mass loss measurements coupled with a post exposure metallographic examination. Complementary potentiodynamic polarization measurements were made in the bulk salt solution to help interpret the relative performance. The elevated Cr content provided by the chromizing surface treatment provides comparable corrosion resistance to the more highly alloyed ferritic stainless steels studied. The major factor affecting localized corrosion susceptibility is the formation of rust deposits, which act as effective pit-like corrosion initiation sites.


Alloy Digest ◽  
1999 ◽  
Vol 48 (5) ◽  

Abstract J and L Types 409 HP are ferritic stainless steels with 11% chromium. They exhibit an excellent combination of good formability, economy, and resistance to oxidation and corrosion. It is typically used in automotive exhaust systems. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-743. Producer or source: J & L Specialty Steel Inc.


2019 ◽  
Vol 55 (8) ◽  
pp. 3684-3699 ◽  
Author(s):  
Tianlong Liu ◽  
Xiaofei Zhu ◽  
Lijia Chen ◽  
Hongyun Bi ◽  
Yingfei Lin ◽  
...  

2013 ◽  
Vol 302 ◽  
pp. 252-257 ◽  
Author(s):  
Huai Yi Chiu ◽  
Chen Ming Kuo ◽  
Huei Sen Wang

In order to investigate the creep behavior and understand its deformation mechanism of automotive exhaust pipe materials, this study conducted creep experiments of 409L and 436 ferritic stainless steels at both 600°C and 750°C under different stress levels. After creep tests, crept specimens were analyzed on the microstructure and fracture surfaces by the use of scanning electron microscopy. From creep data, two important material coefficients, namely, M of Monkman-Grant relationship and K of Coble creep equation are calculated for predicting the material creep life. Results show the creep resistance of 436 stainless steel is better than that of 409L stainless steel, because the 436 stainless steel has more Ni, Cr, and Mo contents. As the creep mechanism, all tests show grain boundary diffusion or Coble creep is the dominate deformation mechanism, except at higher temperature 750 °C and higher stress levels.


Author(s):  
Younggi Lee ◽  
Gyeongcheol Lee ◽  
Jaeseong Kim ◽  
Boyoung Lee

Ferritic stainless steels have excellent stress corrosion resistance and a low coefficient of thermal expansion compared to austenitic stainless steels. Ferritic stainless steels of the 400 series have been available for automotive exhaust systems, heat exchangers, radiators etc. in various industries. Automotive exhaust manifolds especially require good heat resistance because the typical operation temperature(800°C) of the exhaust system is exposed to during engine operation. In this study, the effects of high temperature(800°C) characteristics on the mechanical and microstructure properties were investigated for lap joint of ferritic stainless steel(STS 429) mainly used as the automotive exhaust manifolds. The microstructure of lap joint was characterized by optical microscopy(OM), scanning electron microscopy(SEM) and X-ray diffraction(XRD). The mechanical property of lap joint was evaluated by tensile test. The tensile test results show that a significant decrease in ultimate tensile strength(between 82 and 85%) was observed for aged STS 429 when tested at the evaluated temperature(800°C). The tensile strength was significantly influenced by growth of grain in the heat affected zone(HAZ). The XRD results show that chromium carbide and chromium nitride phases such as Cr23C6, Cr7C3, Cr2N and TiN were precipitated in the heat affected zone(HAZ).


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