Innovative Stainless Steel Applications in transport ... - Euro Inox

grade 304SP was to increase pitting resistance and bring it closer to the level of classic
molybdenum-alloyed commodity grades. Previous internal R&D work on leaner
formulations has eventually led to the optimum 304SP composition being established
(Table 2). Regarding other main characteristics, the produced and tested 304SP is much
like the original 1.4301 grade.
Table 2. Typical chemical composition of the BUS project 304SP heats (in weight %).
C S Si Mn Cr Ni Mo N
0.052 0.001 0.28 0.20 18.10 8.30 0.74 0.099
Grade 1.4318 (AISI 301LN)
Grade 1.4318 with lower carbon and higher nitrogen content is preferable to 1.4310 on
account of its improved strength-to-ductility ratio (Table 3). Furthermore, it possesses a
higher work-hardening rate than traditional 1.4301 grade stainless steel (Figure 28).
Grade 1.4318 is often used in structural-component applications where high strength has
to be combined with good corrosion properties. In terms of corrosion resistance, grade
1.4318 is similar to 1.4301. High-power-density welding methods are recommended for
welding cold-worked components, in order to limit the softening effect of heat in the
weld area.
Figure 28. Typical stress-strain curves for stainless and carbon steel in annealed condition (for
longitudinal tension) (Euro Inox, 2006b).
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