Activities per year
Abstract
Modern steel industry has great interest in developing new advanced high-strength steels, especially for the automotive industry. The need for stronger and more ductile sheet steels has led to development of novel heat treatments such as quenching and partitioning. The Q&P heat treatment provides an opportunity of manufacturing strong steels without sacrificing their formability. However, there is limited research conducted on the microstructure evolution of many alloys potential for Q&P such as stainless steels.
This study evaluates the selection for the optimal quench interruption temperature during Q&P of ferritic stainless steels. The paper compares different simulation models for optimizing the Q&P-process. Q&P was applied to two AISI 420-type stainless steels EN 1.4021 and EN 1.4034 to assess the simulation results. Microstructure analyses with X-ray diffraction and electron microscopy revealed that simulated values overestimate the retained austenite fractions after Q&P due to formation of Cr-rich carbides. Mechanical tests showed that Q&P is applicable to grade EN 1.4021 stainless steel, whereas EN 1.4034 fractured in a brittle manner under tensile load. Electron microscopy revealed intergranular fracture type and concentration of Cr-rich carbides at parent austenite grain boundaries in EN 1.4034. These results suggest that impurities may expose stainless steels to temper embrittlement during partition.
Original language | English |
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Article number | 143339 |
Journal | Materials Science and Engineering A |
Volume | 847 |
DOIs | |
Publication status | Published - Jul 2022 |
Publication type | A1 Journal article-refereed |
Keywords
- Q&P
- Ferritic stainless steels
- Retained austenite
Publication forum classification
- Publication forum level 2
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Dive into the research topics of 'Influence of initial quenching on the microstructure and mechanical properties of quenched and partitioned ferritic stainless steels'. Together they form a unique fingerprint.Activities
- 1 Public talk
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Q&P-lämpökäsittelyyn liittyvät ilmiöt ferriittisissä ruostumattomissa teräksissä
Raami, L. (Speaker)
31 May 2023Activity: Talk or presentation › Public talk
Equipment
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Materials testing and characterization
Valtonen, K. (Contact) & Vippola, M. (Contact)
Materials Science and Environmental EngineeringFacility/equipment: Facility
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Tampere Microscopy Center
Vippola, M. (Manager), Honkanen, M. (Operator) & Salminen, T. (Operator)
Faculty of Engineering and Natural SciencesFacility/equipment: Facility