Lesson 5 - Material Application in Brewing SAQ
This lesson allows you to test yourself on the material covered in the lesson Material Application in Brewing and to determine the level to which you have met the learning outcomes.
Suggested Response - Q4
**How would you compare and contrast austenitic and duplex stainless steels?
Response:
|
Austenitic Stainless Steel |
Duplex Stainless Steel |
|
18% Chromium |
21-26% Chromium |
|
8% Nickel |
3-8% Nickel |
|
2-3% Molybdenum |
3-5% Molybdenum |
|
Low Carbon (0.08% max, 0.03 in L grades) |
|
|
Can include titanium or niobium |
|
|
Easily fabricated, formed |
More difficult to form |
|
Easy to weld |
Slightly more difficult to weld |
|
Non-magnetic |
Magnetic |
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Excellent corrosion resistance |
|
|
Affected by high concentrations of reducing acids |
More resistant to reducing acids |
|
Halide ions, especially chlorine (Cl-), can break down the passive film |
Resistant to halide ions |
|
Susceptible to SCC and crevice corrosion |
Less susceptible to SCC and crevice corrosion |
|
Hygienic finish, easy to clean |
Hygienic surface |
|
Used in most contact applications |
Used in high temperature applications, especially where high chloride levels occur |
|
SS304, SS304L, SS316, SS316L, 317, 321 |
SS2205, 2101, 2304, 2507 |