scholarly journals Problems of Ferrite Content Determination

2020 ◽  
Vol 64 (2) ◽  
pp. 150-158
Author(s):  
Bálint Bögre ◽  
István Mészáros
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Ferrite Content ◽  
Super Duplex Stainless Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Content Determination ◽  
Heat Treated ◽  
Δ Ferrite ◽  
Cold Rolled

In this work five different methods – AC magnetometer, DC magnetometer, Feritscope, EBSD and X-ray diffraction - were compared with each other. These methods were used to determine the δ-ferrite content of samples. The limits, disadvantages and advantages of the applied methods were analyzed. The tested material was 2507 type super-duplex stainless steel. The samples were cold rolled and heat treated to modify their ferrite content.

scholarly journals Complex Study of Eutectoidal Phase Transformation of 2507-Type Super-Duplex Stainless Steel

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2205 ◽  
Author(s):  
István Mészáros ◽  
Bálint Bögre
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Phase Transformation ◽  
Cold Rolling ◽  
Super Duplex Stainless Steel ◽  
Heat Treated ◽  
Δ Ferrite ◽  
Eutectoidal Decomposition ◽  
Cold Rolled ◽  
Sample Set

The aim of this work was to study expansively the process of the eutectoidal phase transformation of 2507-type super-duplex stainless steel. Three sample sets were prepared. The first sample set was made to investigate the effect of the previous cold rolling and heat treatment for the eutectoidal phase transformation. Samples were cold rolled at seven different rolling reductions which was followed by heat treatment at five different temperatures. The second sample set was prepared to determine the activation energy of the eutectoidal decomposition process using the Arrhenius equation. Samples were cold rolled at seven different rolling reductions and were heat treated at the same temperature during eight different terms. A third sample set was made to study how another plastic-forming technology, beside the cold rolling, can influence the eutectoidal decomposition. Samples were elongated by single axis tensile stress and were heat treated at the same temperature. The results of the first and the third sample sets were compared. The rest δ-ferrite contents were calculated using the results of AC and DC magnetometer measurements. DC magnetometer was used as a feritscope device in this work. Light microscope and electron back scattering diffraction (EBSD) images demonstrated the process of the eutectoidal decomposition. The thermoelectric power and the hardness of the samples were measured. The results of the thermoelectric power measurement were compared with the results of the δ-ferrite content measurement. The accurate value of the coercive field was determined by a Foerster-type DC coercimeter device.

In Situ X-Ray Diffraction Study of Load Partitioning and Microyielding for the Super Duplex Stainless Steel SAF2507 (UNS S32750)

2006 ◽  
Vol 524-525 ◽  
pp. 847-852 ◽  
Author(s):  
Ru Lin Peng ◽  
J. Gibmeier ◽  
Sebastian Eulert ◽  
Sten Johansson ◽  
Guo Cai Chai
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Deformation Behaviour ◽  
Uniaxial Tensile ◽  
Super Duplex Stainless Steel ◽  
X Ray Diffraction ◽  
Austenitic Phase ◽  
X Ray ◽  
Applied Stresses

The deformation behaviour of the super duplex stainless steel SAF2507 (UNS S32750) under successive uniaxial tensile loading-unloading was investigated with respect to load sharing and inter-phase interactions. The steel consists of 58% austenite and 42% ferrite in volume. By insitu X-ray diffraction experiment the evolution of phase-specific stresses with applied load was monitored for three successive loading-unloading cycles with the maximum total strains being 0.34%, 0.75% and 1.63%, respectively. It was found that yielding occurred earlier in the austenitic phase than in the ferritic phase during the first loading cycle. In the followed loading cycles, both phases yielded under larger but similar applied stresses. Due to a similar behavior of the phases in the elasto-plastic regime inter-phase interactions were relatively weak. Low microstresses induced by the plastic straining resulted in somewhat larger stresses in the ferritic phase.

scholarly journals Evaluation of Internal Stress in Individual Grains of Cold-Rolled Stainless Steel by Energy Dispersive X-ray Diffraction

2013 ◽  
Vol 53 (1) ◽  
pp. 165-169 ◽  
Author(s):  
Kentaro Kajiwara ◽  
Masugu Sato ◽  
Tamotsu Hashimoto ◽  
Takuyo Yamada ◽  
Takumi Terachi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Internal Stress ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cold Rolled ◽  
Individual Grains

Effects of N Content on Microstructure and Properties of SAF2906 Casting Super Duplex Stainless Steel after Cryogenic Treatment

2010 ◽  
Vol 139-141 ◽  
pp. 670-676
Author(s):  
Hong Liang Xiang ◽  
Dong Liu ◽  
Wei Lin Huang ◽  
Fu Shan He
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Cryogenic Treatment ◽  
Optical Microscope ◽  
Super Duplex Stainless Steel ◽  
X Ray Diffraction ◽  
Alloying Element ◽  
N Content ◽  
Relationship Of

SAF2906 is a new kind of super duplex stainless steel, and more corrosion-resistant and strong than SAF2507, suitable to be used in the low temperature and corrosion conditions. In order to prevent the occurrence of microstructure changes resulting in the property deterioration, in the general, the castings made for SAF2906 should be cryogenically treated before they are used in the ultra low conditions. N is an alloying element, usually added to stainless steels to increase the material properties. So, In this paper, the effects of N content on microstructure, mechanical and corrosion resistance properties of SAF2906 casting super duplex stainless steel (SDSS) after cryogenic treatment were studied by means of Optical Microscope(OM), X-ray Diffraction(XRD) and electrochemical workstation. The results indicate that N can increase the amount of γ phase according to a linear relationship of Φ(γ)=99.4×w(N)+6.16. When N content is low or medial, γ phase can precipitate from ferrite. When N content is high, γ phase does not precipitate from ferrite and is converted directly from ferrite and austenite grain boundaries. The higher N content, the greater tensile strength and elongation, the better corrosion resistance. Compared with solution state, cryogenic treatment can improve corrosion resistance.

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