The effect of initial microstructure on the final properties of press hardened 22MnB5 steels

Järvinen, Henri; Isakov, Matti; Nyyssönen, Tuomo; Järvenpää, Martti; Peura, Pasi

doi:10.1016/j.msea.2016.08.096

Cited by 40 publications

(23 citation statements)

References 31 publications

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“…[3] The formation of these phases is influenced by hot deformation, whereby a shift of the ferritic and bainitic area to shorter times has been observed at a hot deformation degree of 20 or 40 pct. [4][5][6] A specific adjustment of a mixed microstructure can produce a material with both high strength and elongation, for which phase compositions of martensite and bainite or martensite and ferrite are favorable. [7] The process route of direct press hardening generally consists of austenitizing, hot forming, and quenching the parts.…”

Section: Introductionmentioning

confidence: 99%

“…[7] The process route of direct press hardening generally consists of austenitizing, hot forming, and quenching the parts. [5] A diffusional transformation of austenite into ferrite or bainite is preferred in non-isothermally deformed boron steels according to Shi et al, which also resulted in a lower martensite start temperature M s . [8] Zhou et al found that austenitization at a temperature of 800°C or 850°C leads to a microstructure consisting of undissolved pearlite, fragmentary ferrite, and martensite.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of Phase Transformations During Graded Thermo-Mechanical Processing of Press-Hardening Sheet Steel 22MnB5

Reitz

Grydin

Schaper

2020

Metall Mater Trans A

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Safety-relevant components in automobiles require materials that combine high strength with sufficient residual ductility and high-energy absorption. A graded thermo-mechanical treatment of the press-hardening steel 22MnB5 with graded microstructure can provide a material with such properties. Different austenitization temperatures, cooling and forming conditions within a sheet part lead to the development of microstructures with mixed phase compositions. To determine the resulting phase contents in such graded processed parts, a large number of dilatometric tests are usually required. With a non-contact characterization method, it is possible to detect local phase transformations on an inhomogeneously treated flat steel specimen. For press-hardening steel after heat treatment and thermo-mechanical processing, correlations between austenitization temperature, hot deformation strain, microstructure, and hardness are established.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterization of Phase Transformations During Graded Thermo-Mechanical Processing of Press-Hardening Sheet Steel 22MnB5

Reitz

Grydin

Schaper

2020

Metall Mater Trans A

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“…The use of AHSS, specially the 22MnB5-galvanealed, directly affects the welding process. The welding process plays an important role in the productivity, performance, maintenance, and quality improvement [7,8]. Especially, the resistance spot welding (RSW), which is extensively used in the automobile industry during the vehicle components construction [9][10][11].…”

Section: Of 25mentioning

confidence: 99%

Optimization of the Resistance Spot Welding Process of 22MnB5-Galvannealed Steel Using Response Surface Methodology and Global Criterion Method Based on Principal Components Analysis

Ribeiro

Romão

Luz

et al. 2020

Metals

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The 22MnB5-galvannealed steel is extensively used in the hot stamping process to produce car anti-collision structure parts. Furthermore, the resistance spot welding (RSW) is an important process in the automobile industry, especially in body construction, and the 22MnB5-galvannealed steels are a big challenge for the joining methods because their microstructure and mechanical properties are different from those of the conventional steels. In view of this, the present paper aims to optimize the parameters of the RSW process of the 22MnB5-galvannealed steel. Initially, the goal was to remove the galvannealed coating and in the next stage, the following responses were maximized: the nugget width, the nugget cross-sectional area, the penetration, the strength, the joint efficiency, and the energy absorption, whereas the indentation, heat affected zone and separation were used as constraints. The process parameters selected were the effective welding time, the effective welding current, the quenching time, and the upslope time. Response surface methodology (RSM) was applied jointly with the global criterion method based on principal components. The results of the multiobjective optimization are close to the individual targets for each response, highlighting the importance of considering the correlation structure presented in the responses.

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“…3). Jarvinen et al [14] reported that the initial microstructure of boron steel is important when the optimal mechanical properties are desired in the press hardening process. The process parameter of the direct press hardening process involves austenitizing, forming at higher temperature and quenching.…”

Section: Alloy Design and Microstructurementioning

confidence: 99%

Effect of molybdenum addition on hardenability of chromium-boron steels used for press hardening applications

Deepa¹,

Sahoo²,

Dhua³

2018

J min metall B Metall

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Two laboratory heats of low-Carbon low-alloy steels, one with boron and chromium additions and other with boron, chromium and molybdenum additions were made and cast into pencil ingots. These ingots were hot-rolled to 2 mm sheets suitable for press hardening application in an experimental rolling mill. A detailed study was made on the effect of various alloying elements on the microstructure and mechanical properties of these steels. A significantly higher hardness (~496 VHN), yield strength (~1137 MPa) and ultimate tensile strength (~1673 MPa) with comparable elongation (~6%) could be achieved in the as rolled and water-quenched Mo-Cr-B steel in comparison to Cr-B steel under similar processing condition. Moreover, a reduction of critical cooling rate by10 o C/s was observed in this steel to obtain fully martensitic structure. The combined addition of boron, chromium and molybdenum was found to be more effective than that of boron and chromium in enhancing the microstructure and mechanical properties of boron-added steels. Additionally, a few hot compression tests were carried out to simulate the press hardening process of these experimental steels. It was found that one of the press hardening process parameters, viz., prior strain had a greater impact on the transformation behaviour of Cr-B and Mo-Cr-B steels during cooling.

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The effect of initial microstructure on the final properties of press hardened 22MnB5 steels

Cited by 40 publications

References 31 publications

Characterization of Phase Transformations During Graded Thermo-Mechanical Processing of Press-Hardening Sheet Steel 22MnB5

Characterization of Phase Transformations During Graded Thermo-Mechanical Processing of Press-Hardening Sheet Steel 22MnB5

Optimization of the Resistance Spot Welding Process of 22MnB5-Galvannealed Steel Using Response Surface Methodology and Global Criterion Method Based on Principal Components Analysis

Effect of molybdenum addition on hardenability of chromium-boron steels used for press hardening applications

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