Magnetic measurements of martensitic transformation in austenitic stainless steel after room temperature rolling

Mumtaz, Khalid; Takahashi, Seiki; Echigoya, J.; Kamada, Y.; Zhang, L. F.; Kikuchi, Hiroaki; Ara, K.; Sato, Masaya

doi:10.1023/b:jmsc.0000007731.38154.e1

Cited by 107 publications

(70 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Recently, other magnetic hysteresis properties such as coercive force and remanence have been extensively investigated because they also provide useful information about the martensite transformation. [4][5][6][7][8][9][10] It was revealed for plastically deformed 304 stainless steels that the coercive force H c depends on the volume fraction and decreases with increasing volume fraction, [6][7][8][9][10] whereas some studies reported an increase. 4,5 This behavior can be due to the interaction of the magnetic domain walls with the ␣Ј-␥ boundaries and the magnetostatic interaction between ␣Ј martensite particles.…”

Section: -3mentioning

confidence: 99%

See 1 more Smart Citation

Characterization of strain-induced martensite phase in austenitic stainless steel using a magnetic minor-loop scaling relation

Kobayashi

Saitô

Takahashi

et al. 2008

Applied Physics Letters

View full text Add to dashboard Cite

We propose a combined magnetic method using a scaling power-law rule and initial permeability in magnetic minor hysteresis loops for characterization of ferromagnetic ␣Ј martensites in austenitic stainless steel. The scaling power law between the hysteresis loss and remanence is universal, being independent of volume fraction of strain-induced ␣Ј martensites. A coefficient of the power law largely decreases with volume fraction, while the initial permeability linearly increases, reflecting a change in the morphology and quantity of martensites, respectively. The present method is highly effective for integrity assessment of austenitic stainless steels because of the sensitivity and extremely low measurement field. © 2008 American Institute of Physics. ͓DOI: 10.1063/1.2924305͔ Austenitic stainless steels have been widely used for the manufacture of power plant structural components because of their high ductility, high corrosion resistance, high strength, etc. When subjected to external factors such as stress, fatigue, radiation, and creep, various types of lattice defects are induced. In particular, understress and dislocations are produced and piled up, and cracks are formed when the dislocation density locally maximizes. For 304 stainless steels with a metastable austenitic matrix, this degradation is always associated with martensite transformation. The accurate characterization of martensites therefore plays a key role in the integrity assessment of power plant components during operation.For 304 stainless steels, plastic deformation at room temperature induces a transformation from a paramagnetic fcc austenite ͑␥͒ to a ferromagnetic bcc martensite ͑␣Ј͒. 1-3Since ␣Ј martensite is the only ferromagnetic phase in the steel, a magnetic method to detect the initial permeability and/or saturation magnetization has been traditionally used to estimate the volume fraction of ␣Ј martensites in the austenitic matrix. Recently, other magnetic hysteresis properties such as coercive force and remanence have been extensively investigated because they also provide useful information about the martensite transformation.4-10 It was revealed for plastically deformed 304 stainless steels that the coercive force H c depends on the volume fraction and decreases with increasing volume fraction, 6-10 whereas some studies reported an increase. 4,5 This behavior can be due to the interaction of the magnetic domain walls with the ␣Ј-␥ boundaries and the magnetostatic interaction between ␣Ј martensite particles. Therefore, the coercive force is an indicator of the size and distribution of ferromagnetic ␣Ј martensites formed in a paramagnetic austenitic matrix. However, high magnetic fields of the order of 1 MA/ m are required to obtain the values of these properties. This is disadvantageous for the in situ integrity assessment that requires a compact measurement device.On the other hand, for ferritic steels, a relationship between the minor-loop flux density B a * and minor-loop hysteresis loss W F * , obtained at the low and medium f...

show abstract

Section: -3mentioning

confidence: 99%

“…4,5 This may be attributed to the fact that the effects of magnetic fields 0 H on the hysteresis loops were not considered in the analysis. In fact, all dc measurements using instruments such as a SQUID magnetometer [8][9][10] and vibrating sample magnetometer 6,7 yielded a decrease in H c with volume fraction. 4 and the scaling treatment of Eq.…”

Section: -3mentioning

confidence: 99%

Characterization of strain-induced martensite phase in austenitic stainless steel using a magnetic minor-loop scaling relation

Kobayashi

Saitô

Takahashi

et al. 2008

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…Moreover, the degree of martensitic transformation is both temperature and strain dependent [12][13][14][15][16][17][18][19]. An increase in the degree of cold work will assist the transformation, whereas an increase in the temperature exhibits the opposite effect [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Correlation between Fatigue Crack Growth Behavior and Fracture Surface Roughness on Cold-Rolled Austenitic Stainless Steels in Gaseous Hydrogen

Chen

Tsay

et al. 2018

Metals

View full text Add to dashboard Cite

Austenitic stainless steels are often considered candidate materials for use in hydrogencontaining environments because of their low hydrogen embrittlement susceptibility. In this study, the fatigue crack growth behavior of the solution-annealed and cold-rolled 301, 304L, and 310S austenitic stainless steels was characterized in 0.2 MPa gaseous hydrogen to evaluate the hydrogenassisted fatigue crack growth and correlate the fatigue crack growth rates with the fracture feature or fracture surface roughness. Regardless of the testing conditions, higher fracture surface roughness could be obtained in a higher stress intensity factor (∆K) range and for the counterpart cold-rolled specimen in hydrogen. The accelerated fatigue crack growth of 301 and 304L in hydrogen was accompanied by high fracture surface roughness and was associated with strain-induced martensitic transformation in the plastic zone ahead of the fatigue crack tip.

show abstract

“…Most of the conventional austenitic SS are paramagnetic provided they show an austenitic microstructure. However this non-magnetic property declines when: (a) delta ferrite is retained during a rapid solidification process; (b) martensitic transformation occurs by several processes (cold working [10][11][12][13], wearing [14], irradiating with hydrogen ions [15] or reaching cryogenic temperatures [16]); (c) some secondary phases precipitation by heating (sensitization) [17,18]; (d) in high nitrogen-alloyed SS [19,20] the expanded austenite is magnetic.…”

Section: Introductionmentioning

confidence: 99%

Abnormal magnetic behaviour of powder metallurgy austenitic stainless steels sintered in nitrogen

Garcı́a

Martín-Pedrosa

Blanco

2009

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

a b s t r a c tThe magnetic response of AISI 304L and AISI 316L obtained through powder metallurgy and sintered in nitrogen were studied. AISI 304L sintered in nitrogen showed a ferromagnetic behaviour in as-sintered state while AISI 316L was paramagnetic. After solution annealing both were paramagnetic. Magnetic behaviour was analysed by using a vibrating sample magnetometer, a magnetic ferritscope and magnetic etching. A microstructural characterization was performed by means of optical metallography, X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDS). Some samples when needed were submitted to aged heat treatments at 675 and 875 1C for 90 min, 4, 6, 8 or 48 h. The main microstructural feature found was the presence of a lamellar constituent formed by nitride precipitates and an interlamellar matrix of austenite and/or ferrite. The abnormal magnetic response was explained based on this.

show abstract

Magnetic measurements of martensitic transformation in austenitic stainless steel after room temperature rolling

Cited by 107 publications

References 11 publications

Characterization of strain-induced martensite phase in austenitic stainless steel using a magnetic minor-loop scaling relation

Characterization of strain-induced martensite phase in austenitic stainless steel using a magnetic minor-loop scaling relation

Correlation between Fatigue Crack Growth Behavior and Fracture Surface Roughness on Cold-Rolled Austenitic Stainless Steels in Gaseous Hydrogen

Abnormal magnetic behaviour of powder metallurgy austenitic stainless steels sintered in nitrogen

Contact Info

Product

Resources

About