Increase the capacityof continuous annealing furnaces at Ovako
2012 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Student thesis
Abstract [en]
The capacity of soft annealing of low alloyed tubes at Ovako’s continuous annealing furnaces have been evaluated by comparing how it is done today with information from published and internal articles on the subject. It was found that it is possible to reduce the cycle time by 30 % for one furnace, 55 % for one furnace and 72 % for two furnaces. Two separate fullscale tests were made to assess whether the faster soft annealing procedure was feasible. The tests were performed without any reconstruction of the furnace and were made by continuously vary the speed of the batch inside thefurnace. The temperature in the batch was measured and compared with results from computer simulations of the heating/cooling sequences. The computer simulations were performed in COMSOL. The soft annealing was evaluated according to the SEP-520 standard ,which means evaluating the microstructure and hardness. The results show that the faster heat treatment could yield lower grades than today but still meet it’s requirements. In order to achieve this increase a reconstruction of the furnaces is needed and the reconstruction is briefly treated in the report. Ideas to further increase the speed of the soft annealing procedure are also presented.
Place, publisher, year, edition, pages
2012. , p. 6
Keywords [en]
Soft annealing, spheroidization, heat treatment, OVAKO, capacity ncrease, productivity, continuous furnace, normalization, isothermal annealing, quench and tempering, tubemill, COMSOL, simulation.
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:kth:diva-161909OAI: oai:DiVA.org:kth-161909DiVA, id: diva2:796377
External cooperation
Ovako
Educational program
Master of Science in Engineering - Materials Design and Engineering
Supervisors
Examiners
2015-03-192015-03-192022-06-23Bibliographically approved