Corrosion resisting = steel with a good resistance to uniform or local attack from the environment (e.g.: 1.4404/AISI 316L ; 1.4571/AISI 316Ti);
The environment may be atmospheric at ambient temperature (indoor , rural , urban , industrial , marine) or a solution giving electrochemical conditions.
Heat resisting = steel with a good resistance to oxidation and to the effects of hot gases and combustion products at temperatures higher than 550 oC (e.g. : 1.4828/AISI 309 ; 1.4845/AISI 310S).
2. BY MICROSTRUCTURE
Ferritic = magnetic steel, has good resistance in moderate aggressive environment, cannot be hardened by heat treatment and has poor weldability (e.g.: 1.4016/AISI 430 ; 1.4510/AISI 430Ti);
Austenitic = non magnetic steel, has the best corrosion resistance, with good toughness and good weldability, cannot be hardened by heat treatment (e.g.: 1.4301/AISI 304; 1.4541/AISI 321).
3. BY SIGNIFICANT ALLOYING ELEMENTS
Chromium and Nickel
Chromium and nickel are the main alloying elements in stainless steel. "Cr-steel" is a traditional term for ferritic grades, and "CrNi - steel" can be used for austenitic grades.
Molybdenum
Stainless steel with over 2% Mo, may be called "CrNiMo - steel".
Low carbon
Intergranular corrosion is avoided through low carbon content ( C < 0.03%). These steels are called "Low Carbon steels".
Stabilization
Addition of Titanium prevents the precipitation of chromium carbides especially for heat treatment and/or welding processes.
SURFACE FINISH , TYPE OF PROCESS ROUTE, ROUGHNESS AND REFLECTIVITY
Abbreviation according to
Type of process route
Surface finish
OTELINOX
EN 10088
ASTM A 480 (A666*)
DIN 17441
JIS 4305
Otelinox
Roughness, Ra[mm]
Reflectivity **[%]
1997 edition
1985 edition
Ferritiic
Austenitic
Ferritiic
Austenitic
2H
1/4H
-
f or IIIa
1/4H
2H
Work hardened
Bright
Max
0.30*
21%-49%
21%-66%
1/2H
3/4H
Full H
Remarks : Cold worked to obtain higher strength level
2D
2D
2D
h or IIIb
2D
2D
Coldrolled, heat treated and pickled
Smooth
-
-
-
-
Remarks : Finish for good ductility, but not as smooth as 2B or 2R
2B
2B
2B
n or IIIc
2B
2B
Cold rolled, heat treated, pickled and skin passed
Smoother than 2D
0.05-0.20
0.10-0.35
30%-60%
Max 40%
Remarks : Most common finish to ensure corrosion resistance, smothness and flatness
2R
BA
2R
m or IIId
BA
2R
Cold rolled, bright annealed
Smoother and brigther than 2B, reflective
0.10-0.30
0.05-0.30
22%-54%
22%-65%
BA
Smoother, brigther reflectiver than 2R
0.07-0.15
0.03-0.15
44%-62%
60%-69%
* specific values will be agreed by both Remarks : Without Skin Pass,Tension Leveled , With Skin Pass
