Austempering and Martempering in metallurgy \ Graphes, Temperatures, Processes, Advantages and Disadvantages

1. S.B JAIN INSTITUTE OF TECHNOLOGY
MANAGEMENT AND RESEARCH
MECHANICAL DEPARTMENT
Presented by:- Khushal Hudke
Topic:- Austempering &
Patenting

2. Austempering
Consists of cooling with a rate exceeding the critical cooling rate
betn. The nose of TTT diagram & Ms temp.
Held for a sufficient period for the completion of bainitic
transformation cooling to room temp. at any rate
The product may be upper or lower bainte.

4. Advantages
 Bainite properties are same of martensite & pearlite & too similar
to tempered Martensite
 Structure & properties are intermediate to tempered martenites
without involving in martensitic transformation
 Dimensional stability is more due to absence of retained
austenite

5. Disadvantages
 Hardness is not high
 Different properties of can be achieved but not possible by this
process
 Applicable to high Hardenability steels
 Quite expensive

6. Patenting
 Quenching in molten bath maintained at slightly above or below
the nose of TTT curve
 Product vary from pearlite to upper Bainite
Advantages
 Process is chief
 Good toughness

8. Bibliography
Textbook of Material Science & Metallurgy by V.D. KODGIRE &
S.V. KODGIRE CHAPTER 9. Steel & Heat Treatments page no. 391
to 393

9. THANK YOU