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Sukyoung Hwang, Hirokazu Kato, [Kazuho Okada](https://orcid.org/0000-0003-0183-4528), Myeong-heom Park, Avala Lavakumar, Reza Gholizadeh, Hiroki Adachi, Masugu Sato, Nobuhiro Tsuji

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Exploring unusual Lüders deformation in ultrafine-grained high-Mn austenitic steelFull Terms & Conditions of access and use can be found athttps://www.tandfonline.com/action/journalInformation?journalCode=tmrl20Materials Research LettersISSN: (Print) (Online) Journal homepage: www.tandfonline.com/journals/tmrl20Exploring unusual Lüders deformation in ultrafine-grained high-Mn austenitic steelSukyoung Hwang, Hirokazu Kato, Kazuho Okada, Myeong-heom Park, AvalaLavakumar, Reza Gholizadeh, Hiroki Adachi, Masugu Sato & Nobuhiro TsujiTo cite this article: Sukyoung Hwang, Hirokazu Kato, Kazuho Okada, Myeong-heom Park, AvalaLavakumar, Reza Gholizadeh, Hiroki Adachi, Masugu Sato & Nobuhiro Tsuji (2024) Exploringunusual Lüders deformation in ultrafine-grained high-Mn austenitic steel, Materials ResearchLetters, 12:8, 571-579, DOI: 10.1080/21663831.2024.2359611To link to this article:  https://doi.org/10.1080/21663831.2024.2359611© 2024 The Author(s). 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RES. LETT.2024, VOL. 12, NO. 8, 571–579https://doi.org/10.1080/21663831.2024.2359611ORIGINAL REPORTSExploring unusual Lüders deformation in ultrafine-grained high-Mn austeniticsteelSukyoung Hwanga, Hirokazu Katoa, Kazuho Okadaa,b, Myeong-heom Parka, Avala Lavakumara,c,Reza Gholizadeha, Hiroki Adachid, Masugu Satoe and Nobuhiro TsujiaaDepartment of Materials Science and Engineering, Kyoto University, Kyoto, Japan; bResearch Center for Structural Materials, National Institutefor Materials Science (NIMS), Tsukuba, Japan; cDepartment of Metallurgical and Materials Engineering, Indian Institute of Technology Ropar,Punjab, India; dDepartment of Materials and Synchrotron Radiation Engineering, Graduate School of Engineering, University of Hyogo, Himeji,Japan; eJapan Synchrotron Radiation Research Institute (JARSI), Sayo-gun, Hyogo, JapanABSTRACTUltrafine-grained (UFG) high-Mn austenitic steel exhibited unusual discontinuous yielding on itsstress-strain curve, characterized by a yield drop followed by a stress plateau, indicative of Lüdersdeformation. Utilizing the digital image correlation (DIC) technique, a strain-localized region knownas a Lüders band was observed to propagate during Lüders deformation. Following microstructuralobservations using state-of-the-art techniques such as in-situ synchrotron XRDmeasurement duringthe tensile test and ex-situ S/TEMand SEM-ECCI, dislocationmultiplication, rather than twinning, wastheoretically identified as the primary deformation mechanism responsible for the unusual Lüdersdeformation in UFG high-Mn austenitic steel.ARTICLE HISTORYReceived 18 March 2024KEYWORDSHigh-Mn austenitic steel;yield point; Lüdersdeformation; ultrafine grains;TWIP effect1. IntroductionThe mechanical behavior of polycrystalline materials,including yielding, strain hardening and fracture, isclosely associated with the inhomogeneous deformationoccurring at different scales. Lüders deformation is a typ-ical example of inhomogeneous deformation occurring atthemacroscale, characterized by the formation, propaga-tion and annihilation of a strain-localized region knownas a Lüders band. This phenomenon has been frequentlyobserved in coarse-grained low-carbon ferritic steel witha BCC structure [1,2]. Such Lüders banding is a processof overcoming plastic instability condition, manifestingas discontinuous yielding followed by a stress plateauon the stress-strain curve [3]. Interestingly, ultrafine-grained (UFG) materials also frequently exhibit Lüdersdeformation, irrespective of their crystal structure andCONTACT Sukyoung Hwang hwang.sukyoung.8p@kyoto-u.ac.jp Department of Materials Science and Engineering, Kyoto University,Yoshida-honmachi, Sakyo-ku, Kyoto 606, JapanSupplemental data for this article can be accessed online at https://doi.org/10.1080/21663831.2024.2359611.the presence of solute atoms [4–10]. In UFG pure met-als, such as copper [4], aluminium [5], and IF steel [5],strain localization within the Lüders band is attributedto dislocation multiplication, considering the reducedmean free path for dislocation glide in ultrafine grains.On the other hand, in advanced high-strength steels(AHSS) such as TRIP (Transformation-induced plas-ticity) and TWIP (Twinning-induced plasticity) steels,additional strain-hardening mechanisms can help over-comemacroscopic necking and facilitate the propagationof a strain-localized region, thereby achieving remarkablemechanical properties that combine both high strengthand ductility [6,8,11–14]. UFG TRIP steel demonstratedenhanced strain hardening due to the high internal stressof deformation-inducedmartensite, which facilitated sta-ble propagation of the Lüders band [6]. UFG TWIP steel© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use,distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the AcceptedManuscript in a repository by the author(s) or with their consent.http://www.tandfonline.comhttps://crossmark.crossref.org/dialog/?doi=10.1080/21663831.2024.2359611&domain=pdf&date_stamp=2024-05-31mailto:hwang.sukyoung.8p@kyoto-u.ac.jphttp://creativecommons.org/licenses/by/4.0/572 S. HWANG ET AL.exhibited unusual discontinuous yielding despite its FCCstructure [8,11–14]. Bai et al. [8] reported that such unex-pected discontinuous yielding in Fe-31Mn-3Al-3Si steelwas closely related with the promotion of deformationtwinning, due to the scarce availability of free disloca-tions in ultrafine grains, and it played a critical role inenhancing the strain hardening through the subdivisionof prior austenite grains (the so-called dynamic Hall-Petch effect). While the achievements have establisheda qualitative relationship between deformation twinningand discontinuous yielding (or Lüders deformation), thequantitative contribution of twinning to Lüders defor-mation in high-Mn steel remains unclear. The currentstudy aims to explore the origin of Lüders deformationin UFG high-Mn steel across multiple scales. The macro-scopic Lüders deformation in UFG high-Mn steel wasquantified using digital image correlation (DIC) tech-nique applied during tensile deformation, and it wascorrelated withmicrostructural changes characterized bystate-of-the-art synchrotron XRDmeasurement, S/TEM,and SEM-ECCI.2. Materials andmethodsHigh-Mn steel with a composition of Fe-31Mn-3Al-3Si(wt. %) was used in this study. The as-received bulkplate underwentmulti-pass cold-rolling, achieving a 92%reduction in thickness. An UFG specimen with a meangrain size of 0.65µm was fabricated by annealing thecold-rolled sheet at 700°C for 300 s, followed by waterquenching. Similarly, a fine-grained (FG) specimen witha mean grain size of 4.5µm was fabricated by anneal-ing at 850°C for 600 s, serving as a reference mate-rial that shows continuous yielding. The microstructurewas observed using a field-emission scanning electronmicroscope (FE-SEM: JEOL JSM-7800F) equipped witha backscattered electron (BSE) detector at an acceler-ating voltage of 15 kV. The preparation of specimensfor SEM-BSE, SEM-ECCI, and S/TEM observations isdetailed in the Supplementary Material. The mean grainsize was measured by a line intercept method on SEM-BSE image, counting high-angle grain boundaries andannealing twin boundaries. Tensile tests were performedat room temperature at constant rate of elongation (ini-tial strain rate of 8.3× 10−4 s−1) using sheet-type tensilespecimens, which are described in the SupplementaryMaterial (Figure S1). Small speckle patterns were appliedto the white-painted background of the tensile speci-mens, and DIC images were captured at five FPS duringthe tensile test to evaluate both global and local straindistribution using Vic-2D software.In-situ synchrotron XRDmeasurement with the beamposition fixed was performed with the DIC techniqueduring tensile deformation at the beamline of BL46 XUat SPring-8. The setup and conditions for the experimentare detailed in Supplementary Material (Figure S2). Thefirst five diffraction peaks were analyzed using the convo-lutional multiple whole profile (CMWP) fitting method[15,16]. Detailed fitting results (Figure S3), along withcalculation of dislocation density and stacking fault prob-ability, can be found in the Supplementary Material. Ex-situ observations of deformation microstructures withinand beyond the Lüders band were conducted using scan-ning transmission electron microscopy (S/TEM: JEOLJEM-2100F) operated at 200 kV, and the SEM-electronchanneling contrast imaging (ECCI) technique at anaccelerating voltage of 15 kV. The area fraction of defor-mation twins was quantified on the SEM-ECC imagesusing GIMP 2.10 software, as described in the Supple-mentary Material (Figure S4).3. Results and discussionFigure 1(a and b) show the SEM-BSE images of theUFG and FG specimens, respectively. Both specimensexhibited a fully recrystallized microstructure contain-ing many annealing twins. The UFG and FG speci-mens had mean grain sizes of 0.65 and 4.5µm, respec-tively. Both specimens showedweak textures, with detailsprovided in the Supplementary Material (Figure S5).Figure 1(c) shows the nominal stress-strain curves ofthe UFG and FG specimens. The FG specimen exhib-ited a yield strength (0.2% proof stress) of 300MPa, atensile strength of 632MPa, and a total elongation of66%. The UFG specimen demonstrated a much higheryield strength of 645MPa (upper yield strength), ten-sile strength of 817MPa, and a total elongation of 60%.Such enhancement of mechanical properties in the UFGspecimen has been attributed to a remarkable increasein deformation twinning [8,17]. It should also be notedthat the yielding behavior differed distinctly between theUFG and FG specimens. The UFG specimen showed dis-continuous yielding characterized by a yield drop andsubsequent stress plateau, i.e. Lüders deformation, whilethe FG specimen exhibited continuous yielding behavior.The yield drop of 11MPa was caused by local yielding,and its propagationmanifested as a Lüders strain of 0.030(3.0%) during the stress plateau. DIC movies illustratingthe changes in local strain rate (Movie 1) and local straindistributions (Movie 2) during Lüders deformation areincluded as Supplementary Material, capturing the for-mation, propagation and annihilation of the Lüders banddistinctly.The in-situ synchrotron XRD measurement and DICanalysis were performed simultaneously during the ten-sile test, and the results are shown in Figure 2. Figure 2(a)MATER. RES. LETT. 573Figure 1. SEM-BSE images of the Fe-31Mn-3Al-3Si steels with mean grain sizes of (a) 0.65 µm and (b) 4.5 µm, observed from thetransverse direction (TD) of the rolled sheet. (c) Nominal stress-strain curves of the UFG and FG specimens.shows the DIC strain-rate maps during the Lüders defor-mation, showing the front of the Lüders band, charac-terized by a higher local strain rate, propagating throughthe tensile specimen from (1) to (5). Hereafter, the frontof the Lüders band will be referred to as the ‘Lüdersfront’, and the process from (1) to (5) as ‘Lüders band-ing’. Changes inXRDprofiles from (1) to (5) are shown indifferent colors in Figure 2(b). During such Lüders band-ing, diffraction peaks shifted and broadened. For detailedinvestigation, five diffraction peaks at moments from (2)to (4), during which the Lüders front was propagatingnear the beam position, are enlarged in Figure 2(c–g).All five diffraction peaks broadened as the Lüders frontpassed through the beam position, indicating that defectswere introduced in the local area of the beam position.Interestingly, however, the direction and extent of peakshifts were complex and differed for each peak, as indi-cated by arrows in the figures. The real-time changesin peak shifts for five diffraction peaks, along with theglobal tensile stress during the early stage of deforma-tion, are presented in Supplementary Material (FigureS6). Normally, yielding behavior relaxes elastic strain(and consequently stress), causing diffraction peaks toshift to higher angles irrespective of the peaks. On theother hand, complex peak shifts observed in this studyare attributed to the generation of stacking faults, whichshift diffraction peaks either to higher or lower anglesdepending on theMiller indices (hkl) of the crystal plane[18]. The CWMP method was employed to effectivelyevaluate both dislocation density and stacking fault prob-ability [19,20]. Figure 2(h) shows changes in dislocationdensity as the Lüders front passed through the beamposi-tion. From (1) to (2), corresponding to the period beforethe Lüders front reached the beam position, dislocationdensity rarely changed. However, from (2) to (4), dur-ing which the Lüders front passed through the beamposition, dislocation density significantly increased. It isnoticeable that the dislocation density increased signif-icantly, by approximately 300 times, from 4.7 × 1012 to1.4 × 1015m−2. From (4) to (5), after the Lüders frontpassed beyond the beam position, dislocation densityreturned to barely changing. Figure 2(i) shows changes instacking fault probability (SFP) from (1) to (5). SFP quan-tifies the chance of forming a stacking fault in the FCC574 S. HWANG ET AL.Figure 2. (a) DIC strain-rate maps showing the Lüders banding observed in the UFG specimen. The yellow point in each DIC imageindicates the position irradiated by incident X-ray beam. (b) The entire angular diffraction pattern during Lüders banding ((1) to (5)), and(c-g) enlarged five diffractions peaks with a black dashed line in each figure indicating the peak center at (2). Changes in (h) dislocationdensity and (i) stacking fault probability, including error bars, during Lüders banding.matrix [20]. Similar to the change in dislocation density,before the Lüders front reached the beam position (from(1) to (2)), SFP remained unchanged. During its passagethrough the beam position (at (3)), there was a notableincrease in SFP, but it reached only 1.8% (at (4)). Sub-sequently, SFP rarely changed after its passage (from (4)to (5)). The results suggest that dislocation multiplica-tion contribute more to Lüders strain than stacking faultsMATER. RES. LETT. 575(or leading partial dislocations), which had a low proba-bility (1.8%) and produced smaller plastic strain due tothe smaller Burgers vector of a leading partial dislocationthan that of a perfect dislocation [21].For direct observation of deformationmicrostructuresassociated with Lüders banding, S/TEM observation wasconducted. As shown in Figure 3(a), the tensile test wasinterrupted at a global strain of e = 0.026, during whichstrain locally accumulated to 0.039 as the Lüders bandswept the right half of the gage part. Subsequently, S/TEMspecimens were prepared for two distinct groups: onewhere the Lüders bandhadnot swept and the otherwherethe Lüders band had already swept. To capture the over-all trend, deformation microstructures in broad areas,Figure 3. (a) DIC local strain map of the UFG specimen at unloading point, and STEM images in regions of (b) the band unswept and(c) the band swept. (d) Deformation microstructure in the region swept by the band, containing (e) a nanotwin and (f ) stacking faults,with an inset of the NBD pattern showing streaks. Note that the image in (f ) appears flipped compared to Figure 3(d) due to the invertedspecimen setting. Tensile direction (TD) is indicated in the figures.576 S. HWANG ET AL.both beyond and within the Lüders band, were observedin STEM mode. The corresponding STEM images areshown in Figure 3(b and c), respectively. The deforma-tion microstructures were clearly different in relation tothe Lüders banding. The local region where the Lüdersband had not swept included a small number of defects(Figure 3(b)), whereas the local region where the Lüdersband had swept contained a large number of defectsacross several grains (Figure 3(c)). For a detailed investi-gation, a regionwhere Lüders band had swept is observedand shown in Figure 3(d). In addition to many dislo-cations, some nanotwins were also observed, with oneof them enlarged in Figure 3(e). It is noteworthy thatdeformation twins are few in number even within theLüders band. As shown in Figure 3(f), many thin plates,each with a thickness of less than 1 nm, formed alongthe grain boundary (or annealing twin boundary). Usingnano beam diffraction (NBD) in STEMmode, these thinplates were identified as possibly being stacking faults, asevidenced by the streaks perpendicular to the stackingfaults in the NBD pattern.To quantify the area fraction of deformation twinsacross a broader area, the SEM-ECCI technique wasemployed, and the results are shown in Figure 4. InFigure 4(a), at a global strain of e = 0.023, the local strainin the region swept by the Lüders band was 0.0413. Sim-ilar to the S/TEM observations, the SEM-ECCI obser-vations were categorized into three groups: one groupwhere the Lüders band had not swept (G1), anotherwhere the band was sweeping (G2), and the other wherethe Lüders band had already swept (G3). As shown in theSEM-ECC images in Figure 4(b–d), in the local regionswept by the Lüders band (G3), there was a noticeableincrease in deformation twins, as well as dislocations andstacking faults, compared to the unswept region (G1).The area fractions of deformation twins in G1, G2, andG3 are shown in Figure 4(e), together with the local straindistribution along the red line across the gage part. Ineach group, approximately 30 grains were observed forthe precise quantification of the area fraction of deforma-tion twins. The area fraction of deformation twins (ftwin)increased from 0.08% (fG1twin) to 0.18% (fG2twin) and thento 0.39% (fG3twin), as the local strain (εxx) increased from0.0046 (εG1xx ) to 0.0219 (εG2xx ) and then to 0.0391 (εG3xx ) dueto local Lüders banding. However, it is noteworthy thatthe area fraction of deformation twins remained as lowas 0.39% even within the Lüders band (fG3twin).Finally, the tensile strain resulting from twinning wastheoretically quantified to evaluate its contribution to themacroscopic Lüders strain (εG3xx ). Figure 5 schematicallydescribes twinning in an FCC matrix.In the schematic, the leading partial dislocationsglided on every (111) layer, with their Burgers vector(�bLP), shifting atoms from their original positions (hol-low circles in the figure) to new positions (solid circles).This process shears (111) layers in the twinned regiontoward the slip direction of the leading partial disloca-tion, with the shear angle of θ . Thus, the shear straingenerated by twinning (γtwin) is calculated as follow:γtwin = tan θ = |�bLP|d(111)(1)where θ is the shear angle, |�bLP| is the magnitude ofthe Burgers vector of the leading partial dislocation, andd(111) is the interplanar distance of the (111) planes.How-ever, the shear strain calculated in Equation (1) must beconverted to tensile strain to assess the contribution oftwinning to the macroscopic Lüders strain (εG3xx ), whilealso considering the effect of crystallographic orienta-tion. In the Taylor model for a uniaxial tensile test, thetensile strain in a unit volume is expressed as:εxx = 1M×∑γ (2)where εxx is tensile strain in a unit volume,∑γ is thesum of shear strain on each slip (or twinning) planewithin a unit volume, and M is the Taylor factor. TheTaylor factor for FCC material with a random texture isknown to be 3.06, and the present material exhibited nostrong texture (Figure S5). Assuming that the primarytwinning system is mostly activated during Lüders defor-mation (γtwin ≈ ∑γ ), as shown in Figure 3(c–e) andFigure 4(c and d), the consequent tensile strain (εtwin)attributed to twinning is estimated to be 0.231. As shownin Figure 4(e), the area fraction deformation twins in theLüders band (fG3twin) was measured to be 0.0039 (0.39%).Therefore, out of the macroscopic Lüders strain (εG3xx ),the contribution of twinning to Lüders strain can becalculated as follow:εtwin × fG3twinεG3xx= 0.0230(2.3%) (3)The small contribution of twinning to the macroscopicLüders strain suggests that dislocation multiplication,rather than twinning, is the primary deformation mech-anism responsible for the Lüders strain in UFG high-Mn steel, as evidenced by the significant increase indislocation density within the propagating Lüders band(Figure 2(h)). Such Lüders deformation in UFG high-Mn steel shares a fundamental mechanism with thatin other conventional UFG materials where dislocationmultiplication serves as the principal mechanism. Therole of twinning in enhancing local strain hardening,which enables the Lüders band to propagate, was beyondMATER. RES. LETT. 577Figure 4. (a) DIC local strain map of the UFG specimen at unloading point. Observations of deformation microstructures were catego-rized into three groups, G1, G2, and G3, considering Lüders banding. SEM-ECC images showing representative deformation microstruc-tures in regions (b) G1, (c) G2, and (d) G3. (e) Area fractions of deformation twins in regions G1, G2, and G3, plotted with the local strainacross the gage part.578 S. HWANG ET AL.Figure 5. Schematic illustration of shear deformation induced by twinning in an FCC matrix.the scope of this study, and further research is neces-sary. Nevertheless, the findings of this study highlight theneed for a careful examination of the TWIP effect, oftenaccepted without adequate scrutiny as the underlyingmechanism for variousmechanical behaviors in high-Mnsteels.4. ConclusionsThis research thoroughly explored the origins of unusualLüders deformation in UFG high-Mn austenitic steel,connecting macroscopic Lüders banding with micro-scopic deformationmechanism. Utilizing the in-situDICtechnique and synchrotron XRD measurement duringthe tensile test, substantial dislocation multiplicationwithin the propagating Lüders band was observed, whilestacking fault probability remained low. Nanosized stack-ing faults were identified through STEM observation,and the area fraction of deformation twins concerningLüders banding was extensively quantified using SEM-ECCI technique. The tensile strain given by twinning wastheoretically estimated based on the experimental find-ings, revealing its contribution to macroscopic Lüdersstrain to be only 2.3%. All results consistently demon-strate that dislocation multiplication, not twinning, wasthe primary deformationmechanism behind the unusualLüders deformation in UFG high-Mn austenitic steel.AcknowledgmentsThe present study was financially supported by JST CREST(JPMJCR1994), Elements Strategy Initiative for StructuralMaterials (ESISM, No. JPMXP0112101000), and the Grant-in-Aid for Scientific Research (S) (No. 20H00306, 20K14608,21K20401, 22K18888, 23H00234, 23K13563 and 23K20037),all through the Ministry of Education, Culture, Sports, Scienceand Technology (MEXT), Japan. All the supports are gratefullyappreciated.Disclosure statementNo potential conflict of interest was reported by the author(s).FundingThis work was supported by Japan Society for the Promotionof Science [grant number 20H00306, 22K18888, 23H00234,23K20037];Ministry of Education, Culture, Sports, Science andTechnology [grant number JPMJCR1994].References[1] Fujita H, Miyazaki S. Lüders deformation in polycrys-talline iron. Acta Metall. 1978;26(8):1273–1281. doi:10.1016/0001-6160(78)90012-3[2] Gao S, Shibata A, ChenM, et al. Correlation between con-tinuous/discontinuous yielding and hall–petch slope inhigh purity iron.Mater Trans. 2014;55:69–72. doi:10.2320/matertrans.MA201326[3] Schwab R, Ruff V. On the nature of the yield point phe-nomenon. Acta Mater. 2013;61:1798–1808. doi:10.1016/j.actamat.2012.12.003[4] Tian YZ, Gao S, Zhao LJ, et al. Remarkable transitionsof yield behavior and Lüders deformation in pure Cu bychanging grain sizes. 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Mater Sci Eng A.2001;300:125–134. doi:10.1016/S0921-5093(00)01788-3https://www.sciencedirect.com/science/article/pii/S0921509300017883https://doi.org/10.1016/j.scriptamat.2020.02.001http://www.sciencedirect.com/science/article/pii/S1359646220300579https://doi.org/10.1038/s41598-019-48271-5https://doi.org/10.1007/s12540-023-01595-4https://www.frontiersin.org/articles/10.3389/fmats.2020.00070https://doi.org/10.1016/j.jmst.2021.01.031https://www.sciencedirect.com/science/article/pii/S1005030221001699https://www.frontiersin.org/articles/10.3389/fmats.2021.599534https://doi.org/10.1016/j.actamat.2021.117549https://doi.org/10.1107/S0021889899009334https://doi.org/10.1038/s41598-021-98875-zhttps://doi.org/10.1063/1.1702312https://doi.org/10.1016/S0921-5093(00)01788-3https://www.sciencedirect.com/science/article/pii/S0921509300017883 1. Introduction 2. Materials and methods 3. Results and discussion 4. Conclusions Acknowledgments Disclosure statement Funding References<<  /ASCII85EncodePages false  /AllowTransparency false  /AutoPositionEPSFiles false  /AutoRotatePages /PageByPage  /Binding /Left  /CalGrayProfile ()  /CalRGBProfile (Adobe RGB \0501998\051)  /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2)  /sRGBProfile (sRGB IEC61966-2.1)  /CannotEmbedFontPolicy /Error  /CompatibilityLevel 1.5  /CompressObjects /Off  /CompressPages true  /ConvertImagesToIndexed true  /PassThroughJPEGImages false  /CreateJobTicket false  /DefaultRenderingIntent /Default  /DetectBlends true  /DetectCurves 0.1000  /ColorConversionStrategy /sRGB  /DoThumbnails true  /EmbedAllFonts true  /EmbedOpenType false  /ParseICCProfilesInComments true  /EmbedJobOptions true  /DSCReportingLevel 0  /EmitDSCWarnings false  /EndPage -1  /ImageMemory 524288  /LockDistillerParams true  /MaxSubsetPct 100  /Optimize true  /OPM 1  /ParseDSCComments false  /ParseDSCCommentsForDocInfo true  /PreserveCopyPage true  /PreserveDICMYKValues true  /PreserveEPSInfo false  /PreserveFlatness true  /PreserveHalftoneInfo false  /PreserveOPIComments false  /PreserveOverprintSettings false  /StartPage 1  /SubsetFonts true  /TransferFunctionInfo /Remove  /UCRandBGInfo /Remove  /UsePrologue false  /ColorSettingsFile ()  /AlwaysEmbed [ true  ]  /NeverEmbed [ true  ]  /AntiAliasColorImages false  /CropColorImages true  /ColorImageMinResolution 150  /ColorImageMinResolutionPolicy /OK  /DownsampleColorImages true  /ColorImageDownsampleType /Bicubic  /ColorImageResolution 300  /ColorImageDepth -1  /ColorImageMinDownsampleDepth 1  /ColorImageDownsampleThreshold 1.50000  /EncodeColorImages true  /ColorImageFilter /DCTEncode  /AutoFilterColorImages true  /ColorImageAutoFilterStrategy /JPEG  /ColorACSImageDict <<    /QFactor 0.40    /HSamples [1 1 1 1] /VSamples [1 1 1 1]  >>  /ColorImageDict <<    /QFactor 0.40    /HSamples [1 1 1 1] /VSamples [1 1 1 1]  >>  /JPEG2000ColorACSImageDict <<    /TileWidth 256    /TileHeight 256    /Quality 15  >>  /JPEG2000ColorImageDict <<    /TileWidth 256    /TileHeight 256    /Quality 15  >>  /AntiAliasGrayImages false  /CropGrayImages true  /GrayImageMinResolution 150  /GrayImageMinResolutionPolicy /OK  /DownsampleGrayImages true  /GrayImageDownsampleType /Bicubic  /GrayImageResolution 300  /GrayImageDepth -1  /GrayImageMinDownsampleDepth 2  /GrayImageDownsampleThreshold 1.50000  /EncodeGrayImages true  /GrayImageFilter /DCTEncode  /AutoFilterGrayImages true  /GrayImageAutoFilterStrategy /JPEG  /GrayACSImageDict <<    /QFactor 0.40    /HSamples [1 1 1 1] /VSamples [1 1 1 1]  >>  /GrayImageDict <<    /QFactor 0.40    /HSamples [1 1 1 1] /VSamples [1 1 1 1]  >>  /JPEG2000GrayACSImageDict <<    /TileWidth 256    /TileHeight 256    /Quality 15  >>  /JPEG2000GrayImageDict <<    /TileWidth 256    /TileHeight 256    /Quality 15  >>  /AntiAliasMonoImages false  /CropMonoImages true  /MonoImageMinResolution 1200  /MonoImageMinResolutionPolicy /OK  /DownsampleMonoImages true  /MonoImageDownsampleType /Bicubic  /MonoImageResolution 600  /MonoImageDepth -1  /MonoImageDownsampleThreshold 1.50000  /EncodeMonoImages true  /MonoImageFilter /CCITTFaxEncode  /MonoImageDict <<    /K -1  >>  /AllowPSXObjects true  /CheckCompliance [    /None  ]  /PDFX1aCheck false  /PDFX3Check false  /PDFXCompliantPDFOnly false  /PDFXNoTrimBoxError true  /PDFXTrimBoxToMediaBoxOffset [    0.00000    0.00000    0.00000    0.00000  ]  /PDFXSetBleedBoxToMediaBox true  /PDFXBleedBoxToTrimBoxOffset [    0.00000    0.00000    0.00000    0.00000  ]  /PDFXOutputIntentProfile (None)  /PDFXOutputConditionIdentifier ()  /PDFXOutputCondition ()  /PDFXRegistryName ()  /PDFXTrapped /False  /Description <<    /ENU ()  >>>> setdistillerparams<<  /HWResolution [600 600]  /PageSize [609.704 794.013]>> setpagedevice