ROLLING HISTORY IN RELATION TO THE TOUGHNESS OF SHIP PLATE
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-inch for Class B; 1-1/4-inch for Class C) following both isothermal and non-isothermal schedules with reductions from 15 percent to 60 percent and temperatures in the range 1250F (677C) to 2000F (1093C). The principal measurements for toughness evaluation were the 15 foot-pound V-notch Charpy, the 50 percent-fibrous Charpy, and the tensile-ductility transition temperatures. The superior toughness of Class C at constant grain size was an example of an extra-grain-size effect of composition. Normalizing of Class B plates after rolling produced Widmanstatten structure and some embrittlement which was interpreted as an apparent extra-grain-size effect of this particular heat treatment. Mechanical fibering was studied with techniques that included electron microscopy, but the contribution of microfissuring effects to toughness was too subtle for observation. Embrittlement from residual cold work as a consequence of low-temperature finishing was also identified. Results of heat treatment after rolling were studied in detail. (Author)
- Rept. on proj. Mill Rolling Practice.
Massachusetts Institute of TechnologyCenter for Transportation Studies, Room 1121
Cambridge, MA United States 02139
- Kapadia, B M
- Backofen, W A
- Publication Date: 1965-5
- Pagination: 55 p.
- TRT Terms: Brittleness; Grain size (Geology); Hot rolling; Metal heating; Metal working; Metallurgy; Plate bearing test; Steel; Steel plates; Toughness
- Identifier Terms: Ship Structure Committee
- Uncontrolled Terms: Heat treatment; Metal structure
- Old TRIS Terms: Charpy tests; Rolling metallurgy; Ship plates
- Subject Areas: Marine Transportation; Materials;
- Accession Number: 00327728
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: SSC-168 Final Rpt.
- Contract Numbers: NObs-88282
- Files: TRIS
- Created Date: Feb 18 1981 12:00AM