Improvement in Mechanical Properties of 42CrMo4 Steel Through Novel Thermomechanical Processing Treatment
- PDF / 3,096,204 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 13 Downloads / 234 Views
TECHNICAL ARTICLE
Improvement in Mechanical Properties of 42CrMo4 Steel Through Novel Thermomechanical Processing Treatment Arun S. Thakare1 · S. P. Butee1 · K. R. Kamble1 Received: 30 May 2020 / Revised: 12 September 2020 / Accepted: 16 September 2020 © ASM International 2020
Abstract Precipitation hardening ferritic pearlitic (PHFP) grade 42CrMo4 steel was subjected to thermomechanical processing (TMP) comprising 0.2–0.6 strain, followed by isothermal holding at 350–650 °C. Optical microscopy performed along with SEM and simulation results using forge NxT 3.0 est disponible simulation software revealed a transformation from initial ferrite– pearlite microstructure to a ferrite–bainite microstructure for lower holding temperatures, revealing different morphologies of these phases/phase mixtures, apart from a monotonic reduction in phase/phase mixture’s and carbides precipitate size. This TMP steel being made by a simple 2-step route demonstrated an improvement in both UTS by 20% and elongation by 10% in comparison with the same grade conventionally hardened and tempered steels comprising large number of manufacturing steps. YS and impact toughness recorded a significant improvement by almost 82 and 70% in comparison with as-received annealed samples. Keywords Thermomechanical processing (TMP) · Precipitation hardening ferritic pearlitic (PHFP) steels · Isothermal holding · Microstructure · Simulation validation
Introduction High-performance forged automobile parts are commonly manufactured using the conventional quenched and tempered (Q&T) steels, involving a large number of manufacturing stages such as hot forging, machining, hardening, quenching, intermediate machining, reheating, tempering with furnace holding, final machining, and stress relieving stage. In the recent past, precipitation hardening ferritic pearlitic (PHFP) steels have been looked as a potential alternative to replace these steels as the number of manufacturing stages gets largely reduced, contributing to a large saving in the production time involved [1–4]. The PHFP steels require only controlled cooling from hot forging temperatures, followed by finish machining and stress relieving, * Arun S. Thakare [email protected] S. P. Butee [email protected] K. R. Kamble [email protected] 1
Department of Metallurgy and Materials Science, College of Engineering, Pune 411005, India
thereby eliminating many intermediate heat treatment steps involved [5–8]. A good combination of strength and ductility with moderate hardness is a primary requirement among most of the forged parts [9]. Steels processed through both these routes are required to satisfy both strength and toughness required by the automobile components [1, 5, 6]. Highperformance automobile components like crankshaft, diesel engine connecting rod, gear wheel, pinion shaft, and rotating parts of trucks as well as an aerospace application such as undercarriage system, load-bearing members, and eye-end control rods are a few of the potential applications which are looked upon from
Data Loading...
