Austempering and Martempering in Metallurgy

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 & M s 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 .

3. 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

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

5. 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

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

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