STAINLESS STEELS

Question 1

WHAT TYPE OF STAINLESS STEEL IS NON-MAGNETIC

Answer 1

AUSTENITIC STAINLESS STEEL

Question 2

WHAT ARE THE 5 CATEGORIES OF STAINLESS STEEL?

Answer 2

• FERRITIC
• MARTENSITIC
• AUSTENITIC
• PRECIPITATION HARDENING
• DUPLEX

Question 3

HOW MUCH CHROMIUM AND CARBON DOES FERRITIC STAINLESS STEEL CONTAIN?

Answer 3

• CHROMIUM -> 12-30%
• CARBON <0.2%

Question 4

HOW MUCH CHROMIUM AND CARBON DOES MARTENSITIC STAINLESS STEEL CONTAIN?

Answer 4

• CHROMIUM -> 12-17%
• CARBON -> UP TO 1.1%

Question 5

HOW MUCH CHROMIUM, CARBON AND NICKEL DOES AUSTENITIC STAINLESS STEEL CONTAIN?

Answer 5

• CHROMIUM -> 16-25%
• CARBON -> <0.08%
• NICKEL -> 7-20%

Question 6

WHAT IS SENSITIZATION?

Answer 6

Sensitization occurs when SS become susceptible to localized intergranular corrosion when
chromium carbides nucleate and grow at the grain boundaries during high temperature exposure
(425 – 815 C) —–when could this occur? During welding.

Question 7

HOW TO OVERCOME SENSITIZATION?

Answer 7

1. Heat treat the weld to dissolve the carbides and fast cool through the sensitizing temp
   zone
2. Lower the carbon content (less carbon less carbides-less chrome needed) get 304L or
   316L
3. Add stabilizing elements to tie up the carbon

Question 8

HOW MUCH CHROMIUM, CARBON, NICKEL, AND ALUMINUM DOES PRECIPITATION HARDENING STAINLESS STEEL CONTAIN?

Answer 8

VARIOUS PERCENTAGES.

Question 9

HOW MUCH CHROMIUM, CARBON, NICKEL AND MOLYBDENUM DOES DUPLEX STAINLESS STEEL CONTAIN?

Answer 9

• CHROMIUM -> 21-23%
• CARBON -> 0-0.03%
• NICKEL -> 4.5-6.5%
• Mo -> 2.5-3.5%