

http://support.spring8.or.jp/Report_JSR/PDF_JSR_31A/2019A1648.pdf

2019A1648BL19B2

ඃࢀࡓᙉᗘᘏᛶࣂࣛࣥࢫࢆᣢࡘ 0.15C-2Si-7%Mn 㗰ࡢ ȖЍЍĮ ຍᕤㄏ㉳ኚែᣲືࡢࡑࡢሙ X ⥺ほᐹIn-situ Analysis on ȖЍЍĮ Strain Induced Transformation Behavior of 0.15C2Si-7Mn Ferrite+Austenite Steel with Excellent Strength ̽ DuctilityBalance㫽ሯ ྐ㑻, ఀᮾ ⠜ᚿ
Shiro Torizuka, Atsushi Itoරᗜ┴❧኱Ꮫ኱Ꮫ㝔The Graduate School of Engineering, University of Hyogo
0.1C-2Si-5%Mn 㗰ࡣඃࢀࡓᙉᗘ࣭ᘏᛶࣂࣛࣥࢫࢆᣢࡘࡀࠊ௒ᅇ C ῧຍ㔞ࢆ 0.15%ࠊMn ῧຍ㔞ࢆ7%ࡲ࡛ቑຍࡋࠊ㉸ᚤ⣽ࣇ࢙ࣛ࢖ࢺ࣮࣮࢜ࢫࢸࢼ࢖ࢺ⤌⧊ࢆᙧᡂࡋࡓࠋࡇࡢ㗰࡟ᑐࡋࠊᘬᙇヨ㦂ࡑ
ࡢሙ㏱㐣 X ⥺ᅇᢡࢆ⾜࠸ࠊຍᕤ◳໬⬟ࡢ C ῧຍ㔞౫ᏑᛶࠊMn ῧຍ㔞౫Ꮡᛶࡢ᳨ウࢆ⾜ࡗࡓࠋ࣮࣮࢟࣡ࢻ㸸 ࣇࣞࢵࢩ࣐ࣗࣝࢸࣥࢧ࢖ࢺࠊṧ␃࣮࢜ࢫࢸࢼ࢖ࢺࠊ㉸ᚤ⣽⤌⧊ࠊᘬᙇヨ㦂ࠊࡑࡢሙ㏱㐣 X ⥺ᅇᢡࠊᙉᗘࠊᘏᛶࠊຍᕤㄏ㉳ኚែ⫼ᬒ࡜◊✲┠ⓗ㸸ᵓ㐀⏝㔠ᒓᮦᩱࡢᅜ㝿➇தຊࡣࠊࡑࡢᅜࡢ⏘ᴗ඲యࡢ➇தຊࢆᕥྑࡍࡿ࡜࠸ࡗ࡚ࡶ㐣ゝ࡛ࡣ࡞࠸ࠋᙉ࠸⣲ᮦ⏘ᴗࡀ࠶ࡿ࠿ࡽࡇࡑࠊᙉ࠸⮬ື㌴⏘ᴗࡀ࠶ࡾࠊ⯟✵ᶵ⏘ᴗࠊᶵᲔ⏘ᴗࡀ࠶ࡿࠋ≉࡟⮬ື㌴⏝ࣁ࢖ࢸࣥ䠄㧗ᙉᗘ㗰ᯈ䠅ࡣࠊ⮬ື㌴⏘ᴗࡢ➇தຊࡢ᰿ᖿࢆ࡞ࡍᢏ⾡࡛࠶ࡿࠋࡋ࠿ࡋࠊ㧗ᙉᗘ࡛࠶ࡾࠊఙࡧࡶ኱ࡁࡃࠊ㠎ᛶࡶ㧗࠸࡜࠸࠺ඃࢀࡓࢺ࣮ࢱࣝࣂࣛࣥࢫࢆᣢࡗࡓ㔠ᒓᮦᩱࠊ࠸ࢃࡺ
ࡿ㠉᪂ⓗ࡞㔠ᒓᮦᩱࡣᏑᅾࡋ࡞࠸ࠋࡑࢀࡣࠊࡇࢀࡽࡢᛶ㉁ࡀࢺ࣮ࣞࢻ࢜ࣇࡢ㛵ಀ࡟࠶ࡿ࠿ࡽ࡛࠶ࡿࠋࡍ࡞ࢃࡕࠊᘬᙇᙉࡉࢆୖࡆࢀࡤࠊఙࡧࡸ㠌ᛶࡣపୗࡋ࡚ࡋࡲ࠺ࠋࡇࡢࢺ࣮ࣞࢻ࢜ࣇࡢ㛵ಀࢆᡴ◚ࡋࠊ㠉᪂ⓗᵓ㐀ᮦᩱࢆᐇ⌧ࡍࡿࡇ࡜ࢆ┠ᶆ࡜ࡋ࡚ࠊᡃࠎࡣ◊✲䠄ᅜᐙࣉࣟࢪ࢙ࢡࢺ ⏘Ꮫඹ๰ᇶ♏ᇶ┙◊✲ࣉࣟࢢ࣒ࣛ ࣊ࢸࣟᵓ㐀ไᚚ䠅ࢆ᥎㐍ࡋ࡚ࡁࡓࠋࡲࡓࠊ⌧ᅾ࡛ࡣ SIP㸦ᡓ␎ⓗ࢖ࣀ࣮࣋ࢩࣙࣥ๰㐀ࣉࣟࢢ࣒ࣛ㸧ࣉࣟࢪ࢙ࢡࢺࢆ᥎㐍୰࡛࠶ࡿࠋࡑࡢᡂᯝ࡜ࡋ࡚ࠊ0.1%C-2%Si-5%Mn ⤌ᡂࢆ࣮࣋ࢫ࡜ࡋࡓ 2 ࡘࡢ࣊ࢸࣟ⤌⧊ࢆᚓࡓࠋ୍ࡘࡣ࣐ࣝࢸࣥࢧ࢖ࢺ⤌⧊࡛ࠊᘬᙇᙉࡉ 1400 MPa ⣭࡛㧗ᘏᛶ࡜㧗㠌ᛶࡶྠ᫬࡟㐩ᡂ࡛ࡁࡿྍ⬟ᛶࢆᣢࡘࠋࡶ࠺୍ࡘࡣࣇ࢙ࣛ࢖ࢺ㸩࣮࢜ࢫࢸࢼ࢖ࢺ஧┦⤌⧊࡛ࠊẕ┦࡜ศᩓ┦ࡢᚤ⣽໬࡟ࡼࡗ࡚ࠊᘬᙇᙉࡉࡣ 1200 MPa ࣞ࣋ࣝࡔࡀࠊ30%ࢆ㉸࠼ࡿ኱ࡁ࡞୍ᵝఙࡧ࡜ᒁ㒊ఙࡧࢆేࡏᣢࡘࠋᘬᙇᙉࡉ㹶඲ఙࡧࣂࣛࣥࢫࡣࠊ30000 MPa%ࢆ㉸࠼ࠊ᪤Ꮡ㗰࡟ẚ࡭ᴟࡵ࡚ඃࢀ࡚࠸ࡿ[1]ࠋࡑࡢඃࢀࡓຊᏛⓗ≉ᛶⓎ⌧࣓࢝ࢽࢬ࣒ࢆゎ᫂ࡍࢀࡤࠊ㠉᪂ⓗᵓ㐀ᮦᩱ㛤Ⓨࡢษࡾཱྀࢆぢ࠸ࡔࡍࡇ࡜ࡀ࡛ࡁࠊḟୡ௦⮬ື㌴⏝ࣁ࢖ࢸࣥࡢ㛤Ⓨ࡟ࡘ࡞ࡀࡿࠋ
௒ᅇࠊࡉࡽ࡞ࡿᙉᗘ࣭ᘏᛶࡢྥୖࢆ┠ᣦࡋ࡚ࠊC ῧຍ㔞ࢆ 0.15-0.20%࡟ୖࡆࠊMn ῧຍ㔞ࢆ 7%࡟ୖࡆࡓᮦᩱࢆస〇ࡋࡓࠋ 㛫ᅽᘏ࡟ࡼࡗ࡚࠶ࡽ࠿ࡌࡵࠊᚤ⣽ࣇ࢙ࣛ࢖ࢺ㸩ࢭ࣓ࣥࢱ࢖ࢺ⤌⧊ࢆᙧᡂࡋࠊࡑࢀࢆ⇕ฎ⌮࡟ࡼࡗ࡚ࠊ䠄a䠅ࣇ࢙ࣛ࢖ࢺ㸩࣮࢜ࢫࢸࢼ࢖ࢺࡢ 2 ┦⤌⧊࡜䠄b䠅࣐ࣝࢸࣥࢧ࢖
ࢺ⤌⧊ࡢ 2 ࡘࡢ⤌⧊ࢆ⏕ᡂࡋࡓࠋࣇ࢙ࣛ࢖ࢺ㸩࣮࢜ࢫࢸࢼ࢖ࢺࡢ 2 ┦⤌⧊࡟㛵ࡋ࡚ࡣࠊC ῧຍ㔞ࢆ 0.15ࠊ0.20ࠊ0.30%ࠊMn ࡀ 7%࡜ቑ࠼ࡿࡇ࡜࡟ࡼࡗ࡚ࠊȖ ┦ࡢయ✚⋡ࡀቑຍࡋࠊࡑࡢᏳᐃᛶࡶቑຍࡍࡿࡇ࡜ࡀᮇᚅ࡛ࡁࡿࠋࡑࡢࡓࡵࠊᙉᗘ࡜ᘏᛶࡢ᭦࡞ࡿྠ᫬ྥୖࡀᮇᚅ࡛ࡁࡿࠋ࣐ࣝࢸࣥࢧ࢖ࢺ⤌⧊࡟㛵ࡋ࡚ࡣࠊ㌿఩ᐦᗘࡢୖ㝈ࡸࡑࡢቑຍᣲືࡶࠊ5%Mn ࡢሙྜ࡜␗࡞ࡿࡣࡎ࡛࠶ࡿࠋ࠸ࡎࢀࡶኚᙧ୰ࡢኚែᣲື࠾ࡼࡧ㌿఩ᐦᗘኚ໬ࢆᐃ㔞ⓗ࡟ ᐃࡍࡿࡇ࡜ࡀ┠ⓗ࡛࠶ࡿࠋᐇ㦂㸸ヨᩱࡣ㗰࡛࠶ࡾࠊࡑࡢ⤌ᡂࡣࠊFe-0.15C-2.0Si-7MnࠊFe-0.2C-2.0Si-7MnࠊFe-0.3C -2.0Si-7Mnࠊ࠾
ࡼࡧ Fe-0.1C-2.0Si-10MnࠊFe-0.15C-2.0Si-5MnࠊFe-0.2C-2.0Si-5Mn䠄wt%䠅࡛࠶ࡿࠋࡲࡓࠊSUS304ࠊ

䠉㻡㻣䠉
SUS316 ࡶ⏝࠸ࡓࠋMn 㗰࡟㛵ࡋ࡚ࡣࠊ┿✵⁐ゎࠊ㘫㐀ࠊ 㛫⁁࣮ࣟࣝᅽᘏࢆ≀㉁࣭ᮦᩱ◊✲ᶵᵓ࡟࡚⾜࠺ࠋึᮇ⤌⧊ࢆᚤ⣽ࣇ࢙ࣛ࢖ࢺ㸩ࢭ࣓ࣥࢱ࢖ࢺ⤌⧊࡜ࡋ࡚࠾ࡃࠋࡑࡢᮦᩱࢆ኱Ꮫ࡟࠾࠸࡚⇕ฎ⌮ࢆ⾜࠸࣐ࣝࢸࣥࢧ࢖ࢺ⤌⧊࡜ࡋ࡚࠾ࡃࠋSUS304ࠊSUS316 ࡟㛵ࡋ࡚ࡣࠊරᗜ┴❧኱Ꮫࡢᅽᘏタഛ࡛ࠊ1 ȝm ㉸ᚤ⣽⤌⧊ࢆసࡾฟࡋࡓࠋࡲࡓࠊ⇕ฎ⌮࡟ࡼࡗ࡚ࠊ2 ȝmࠊ5 ȝm ⤌⧊ࡶసࡾฟࡋ࡚࠾ࡃࠋ ᐇ㦂㓄⨨ࢆ Fig.1 ࡟♧ࡍࠋᘬᙇヨ㦂∦ヨᩱࡣᖹ⾜㒊㛗ࡉ 12 mmࠊᖜ 2.5 mmࠊཌࡉ 0.4 mm ࡢᘬᙇヨ㦂∦࡛ࠊBL19B2 ࡢࢦࢽ࣓࣮࢜ࢱୖ࡟タ⨨ࡋࡓᘬᙇࡾヨ㦂ᶵ࡟ྲྀࡾ௜ࡅࡓࠋ2 ḟඖ᳨ฟჾ Pilatusࢆ⏝࠸ࡓࠋ᳨ฟჾࡢ఩⨨ࡣࠊ㕲ࡢሙྜࠊ2ș ࡀ 5-35rࡢ⠊ᅖ࡛ィ ࡛ࡁࡿࡼ࠺࡟ࠊ㐺ษ࡞఩⨨࡟タ⨨ࡋࡓࠋ X ⥺ࡢ࢚ࢿࣝࢠ࣮ࡣ 30 keV ࡜ࡋࡓࠋᮦᩱࡣ㕲㗰ᮦᩱ࡛࠶ࡿࡀᯈཌ 0.5 mm ࡛࠶ࢀࡤ༑ศ࡞ᅇᢡ
ᙉᗘࡀᚓࡽࢀࡓࠋᘬᙇ㏿ᗘࡣࡦࡎࡳ㏿ᗘ 0.26 mm/min࡜࡞ࡿࡼ࠺࡟⾜ࡗࡓࠋᘬᙇⲴ㔜ࡢ ᐃ࡟ࡣࠊ᭱኱Ⲵ㔜
20 N ࡢ࣮ࣟࢻࢭࣝࢆ⏝࠸ࡿࠋᘬᙇヨ㦂ࢆ⾜࠸࡞ࡀࡽ X ⥺ᅇᢡࢆྠ᫬࡟⾜࠺ࠊInsitu ᘬᙇヨ㦂 X ⥺ᅇᢡࢆ⾜ࡗࡓࠋᛂຊ̿ࡦࡎࡳ᭤⥺ࢆྲྀᚓࡋ࡞ࡀࡽࠊᛂຊ̿ࡦࡎࡳ᭤⥺࡟ᑐᛂࡍࡿ X ⥺ᅇᢡࢹ࣮ࢱࢆᚓࡓࠋࢹ࣮ࢱࡢ ᐃ㛫㝸ࡣࠊ1 s ⛬ᗘ࡜ࡋࡓࠋ
ᚓࡽࢀࡓࢹ࣮ࢱࢆࡶ࡜࡟ࠊȖ య✚⋡ࡣᘧ(1)ࢆ⏝࠸࡚ࠊhkl ⌮ㄽᅇᢡᙉᗘ R ࡜ᚓࡽࢀࡓᩓ஘ゅ࡟࠾ࡅࡿ Į ┦㸦110㸧ࠊ㸦200㸧ࠊ㸦211㸧࡜ Ȗ ┦㸦111㸧ࠊ㸦200㸧ࠊ㸦220㸧ࡢࣆ࣮ࢡ㠃✚ᙉᗘẚࡼࡾồࡵࡓࠋ(1)  Fig.1  Schematic    illustration    ofthe in-situ          transmission type X-ray diffraction
suring tensile test system.

   ⤖ᯝ࠾ࡼࡧ⪃ᐹ㸸
Fig.2 ࡟ࠊ675°௚ࠊ700°௚ࠊ725°௚ ࡛ࡑࢀࡒࢀ↝㕌ࡋࡓ౪ヨᮦ䠄0.15%C-5%Mn Į+Ȗ 㗰䠅ࡢබ⛠ᛂຊ㸫බ⛠ࡦࡎࡳ ᭤⥺㸦ᐇ⥺㸧࡜ᘬᙇヨ㦂୰ࡢJయ✚⋡㸦◚⥺㸧ࢆ♧
ࡍࠋ675°௚ ↝㕌ᮦ࡛ࡣ TS ࡀ 1000 MPa ⣭࡛࠶ࡾࠊ᭱㧗Ⲵ㔜Ⅼ࡛Jࡀṧ␃ࡋ࡚࠸ࡓࡢ࡟ᑐࡋࠊ700°௚ ↝㕌ᮦࡣᘬᙇᙉࡉࡀ኱ࡁࡃྥୖࡋࠊ᭱㧗Ⲵ㔜Ⅼ࡛Jࢆࡘ࠿࠸ࡁࡾࠊ
ᘬᙇᙉࡉ 1500 MPa-ఙࡧ 30%ࢆ♧ࡋࡓࠋ725°௚ ↝㕌ᮦࡣ TS ࡀ኱ࡁࡃ࡞ࡗࡓࡶࡢࡢ㏵୰࡛◚᩿ࡋ࡚ࡋࡲ࠸ࠊ඲ఙࡧࡀ኱ࡁࡃῶᑡࡋࡓࠋࡇࢀࡽࡢ⤖ᯝ࠿ࡽࠊ700°௚ ࡀFig.2 Nominal stress – strain curves and᭱㐺࡞↝㕌 ᗘ࡛࠶ࡿࡇ࡜ࡀ᫂ࡽ࠿࡟࡞ࡗࡓࠋ700°௚
change in Ȗ volume fraction with↝㕌ᮦ 0.15C ࡣࠊ675°௚ ↝㕌ᮦ࡜ẚ࡭࡚ࠊึᮇ Ȗ య✚
tensile strain in 0.15C-2Si-5%Mnsteels annealed at 675°௚, 700°௚,⋡ࡀ 15%኱ࡁࡃ࡞ࡾࠊఙࡧ 25%࡛౑࠸ษࡿ㐺ษ࡞Ᏻᐃ725°௚ for 1 h [2].
ᛶࢆ᭷ࡋࡓࡇ࡜࡛ࠊ㉸㧗ᙉᗘ㧗ᘏᛶࡀⓎ⌧ࡋࡓࠋ700°௚
↝㕌ᮦࡢ⤖ᯝ࠿ࡽࠊ௒ࡲ࡛Jయ✚⋡ࡀ 30%ࡲ࡛ࡋ࠿ࠊȖయ✚⋡࡜ TS ࡟┦㛵ࡀ࠶ࡿࡇ࡜ࡀㄆࡵࡽࢀ࡞࠿ࡗࡓࡀࠊȖ య✚⋡ࡀ 50%ࡲ࡛ Ȗ య✚⋡࡜ TS ࡢ㛵ಀ࡟ࡢࡿࡇ࡜ࡀ᫂ࡽ࠿࡟࡞ࡗࡓ[1], [2]ࠋ௒ᚋࡢㄢ㢟㸸ᘬᙇᙉࡉࡀ 1500 MPa ࡟࡞ࡿᶵ㗰࡬ࡢ⌮ゎࢆ῝ࡵࡿࠋMn7%ࡢຠᯝࢆ᫂ࡽ࠿࡟ࡍࡿࠋཧ⪃ᩥ⊩㸸[1] Ᏻ㐩⠇ᒎࠊ㫽ሯྐ㑻ࠊ㊊❧኱ᶞࠊఀᮾ⠜ᚿࠊ㕲࡜㗰, 105, 197䠄2019䠅.
[2] ⵿⏣࿴ᶞࠊ㊊❧኱ᶞࠊ㫽ሯྐ㑻ࠊCAMPS-ISIJ 31-2, PS-99䠄2018䠅.

䠉㻡㻤䠉