Sensitization Behavior of Type 409 Ferritic Stainless Steel: Confronting DL-EPR Test and Practice W of ASTM A763

Alloy Design to Prevent Intergranular Corrosion of Low-Cr Ferritic Stainless Steel with Weak Carbide Formers

“…From EELS analysis, it is revealed that the intermetallic compound consisted of C, Mo, Mn, and Si as shown in Figure 7(a). Electron diffraction pattern analysis on this intermetallic compound identifies it as CMn 4 MoSi, as shown in Figure 7(b). 32 Formation of this CMn 4 MoSi intermetallic compound requires the proper amount of Mo, Mn, and Si because WCF-11 (insufficient Mo content), WCF-12 (insufficient Si content), and WCF-13 (insufficient Mn content) do not form sufficient amount of CMn 4 MoSi intermetallic compound to prevent IGC.…”

“…2,4,13,[26][27][28] The DL-EPR test was conducted in 0.5% H 2 SO 4 solution with 0.0013 wt% KSCN at 30…”

“…The co-addition of Mo, Mn and Si to low-Cr ferritic stainless steel effectively prevents IGC by forming along grain boundaries CMn 4 MoSi intermetallic compounds, which act not only as carbon trap sites but also as diffusion barrier against solute Cr diffusion toward grain boundaries. The low solubility of Cr in the CMn 4 The low-chromium (Cr) ferritic stainless steels (FSSs) are widely used as an economical structural material in moderate corrosive environments because they have high strength and good corrosion resistance. The low-Cr FSSs contain Cr content in a range of 11 to 13 wt% and they are used for automotive exhaust system, chemical processing equipment, furnace parts, heat exchangers, recuperates, oil burner parts and storage vessels.…”

“…Since fusion welding such as gas metal arc welding (GMAW) is a common practice for low-Cr FSS, during service, it often results in a serious industrial problem of sensitization or intergranular corrosion (IGC). [2][3][4] Sensitization occurs quite easily in FSS, which has body centred cubic (BCC) structure, because of its low solubility of interstitial elements of carbon (C) and nitrogen (N). 5 In FSS, sensitization may occur as fast as less than 0.01 s because of high diffusivity of C and N in BCC structure.…”

Comparative Study of Microstructure, Texture, and Formability Between 11CrTi and 11CrTi+Nb ASTM 409 Ferritic Stainless Steel

“…In the automobile industry, the Ti-stabilized ferritic stainless steel, ASTM 409, was developed over 30 years ago particularly for use in automotive exhaust systems, where it is widely used today 1,2 . With 11% chromium, low concentrations of carbon, and nitrogen and titanium stabilization, the ferritic stainless steel, ASTM 409 (UNS S40910), shows good performance in most applications.…”