Effect of Different Quench Media on the Microstructure and Mechanical Properties of Large-Scale Low Alloy Steel Forgings

• Published in: Key Engineering Materials Vol. 716; pp. 270 - 280
• Main Authors: Cerda-Rojas, Rene, Wynne, Bradley P., Mercado-Solis, Rafael D., Saldana-Garza, Edgar Ivan
• Format: Journal Article
• Language: English
• Published: Trans Tech Publications Ltd 01.10.2016
• Subjects: Cooling; Forgings; Mechanical properties; Microstructure; Quenching media; Segments; Tempered martensite; Vegetables; Forging; Mechanical Properties; Cooling Rate; Low Alloy Steel; Microstructure
• ISBN: 9783038357049; 3038357049
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.716.270

Large-scale forging segments with two different section thicknesses (100 and 250 mm) were separately subjected to water, polymer solution and vegetable oil quenching and then tempered to evaluate the influence of cooling rate on microstructure and mechanical properties under industrial conditions. Regardless of quenching media, the fastest cooling rates are obtained in the thin (100 mm) sections of the ring segments. For the two cross sections, water and vegetable oil generated the faster and slower cooling times, whilst an intermediate cooling timebetween that of water and oil was achieved with polymer solution. Slightly enhanced mechanical properties in the thin sections are associated to the presence of fine mixtures of tempered martensite and tempered bainite (lower type morphology) compared to the thick section microstructure mostly composed of coarse tempered bainite with granular and lower type morphologies and small amounts of tempered martensite. The results obtained in this study also suggest the possibility of using vegetable oil as an alternative quenching media for large-scale forgings with high-specification requirements.