ROLLING HISTORY IN RELATION TO THE TOUGHNESS OF SHIP PLATE.
Abstract
Plates of ABS Class-B and Class-C steel were rolled with different temperature-reduction schedules to observe effects of processing history on final structure and properties. Each class was finished at a constant thickness (1-1/2-in. for Class B; 1-1/4-in. for Class C) following both isothermal and non-isothermal schedules with reductions from 15% to 60% and temperatures in the range 1250 (677 C) to 2000 F (1093 C). The principal measurements for toughness evaluation were the 15 ft-lb V-notch Charpy, the 50%-fibrous Charpy, and the tensileductility transition temps. Effects were divided into two basic categories, one concerned entirely with ferrite grain size, the other with various extra-grain-size details of structure and composition. The most significant improvements in toughness were the result of ferrite grain-size refinement. The notch toughness of both steels was increased equally for this reason as rolling temperature was lowered to 1450 F(788 C). The superior toughness of Class C at constant grain size was an example of an extra-grain-size of composition. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1965
- Accession Number
- AD0465025
Entities
People
- B. M. Kapadia
- W. A. Backofen
Organizations
- Massachusetts Institute of Technology