GH 617, GH3128, GH2909, GH3230, GH3044, GH5188, GH4738, GH4202

Takaitaccen Bayani:


  • Farashin FOB:US $0.5 - 9,999 / yanki
  • Min. Yawan oda:Yanki/Kashi 100
  • Ikon bayarwa:10000 Pieces/Perces per month
  • Port:Shanghai, Ningbo, Shenzhen
  • Lokacin bayarwa:7-10 kwanaki bayan tabbatar da oda
  • Asalin:China
  • Lokacin Biyan kuɗi:T/T, L/C
  • Daidaito:ASTM,AISI,SUS,JIS,EN,DIN,GB, ASME da dai sauransu
  • Mill:Pocso / Tisco / Lisco / Jisco / Bao karfe / H Wang
  • Cikakken Bayani

    Ƙayyadaddun Fasaha

    Kunshin Samfura & Jigila

    Gabatarwar Kamfanin

    Tambaya & Amsoshi

    Tags samfurin

    GH617,GH3128,GH2909,GH3230,Gh3044GH 5188.GH4738,GH4202

     

    GH3128 gami da cikakken aikin yana da kyau fiye da irin wannan GH3128 da GH3536 haɗin gwiwa na tushen nickel na zinari. Dace da masana'antu na dogon lokaci aiki a karkashin 950 ℃ na jirgin sama engine combustor harshen wuta tube, afterburner harsashi, tsari da sauran high zafin jiki sassa, main kayayyakin ne sanyi birgima takardar, kuma iya bayar da zafi birgima farantin, mashaya, ƙirƙira, waya da tube.

    GH3128 Superalloy Karfe yawanci ana amfani dashi a cikin masana'antu masu zuwa:
    Aero-engine combustor liner, afterburner casing, flaps
    Tsarin injin turbine combustor
    Abubuwan haɗakarwa injin injin turbine
    Afterburner sassa

    GH3128 Superalloy gami sinadaran abun da ke ciki:

    Alloy

    %

    Ni

    Cr

    Mo

    W

    Fe

    Ti

    C

    Mn

    Si

    V

    Al

    P

    S

    GH3128

    Min

    daidaitawa

    19

    7.5

    7.5

    0.4

    0.1

    0.4

    Max

    22

    9.0

    9.0

    2.0

    0.8

    0.05

    0.5

    0.80

    0.5

    0.4,0.8

    0.013

    0.013

    A resistivity na daban-daban zafin jiki

    θ/ ℃

    20

    100

    200

    300

    400

    500

    600

    700

    800

    ρ/ (10-6Ω.m)

    2.30

    2.49

    2.78

    3.08

    3.39

    3.69

    3.88

    3.92

    1.46

    GH3128 alloy narkewa batu: 1325-1370 ℃
    GH3128 Nickel yawa: 8.90 g/cm3

    GH3128 Superalloy Alloy ya dace da aikin masana'antu a ƙarƙashin 950 ℃ na combustor aeroengine da kayan aikin reheater, Sakamakon GH3128 yana da kyau.

    GH3128 babban fasali:
    Superalloy (GH3128) American brands (American Standard ASTM) Babu daidai maki, mai kyau m bayani ƙarfafa irin nickel tushe gami overall yi, m rayuwa da high, high plasticity, high creep ƙarfi da kuma jurewa mai kyau hadawan abu da iskar shaka juriya da stamping, waldi da sauran kaddarorin. Ayyukansa gabaɗaya ya fi sauran makamantan GH3044 da GH3536 tushen ƙaƙƙarfan bayani gami da nickel.

    GH3128 Samfurin Samfuri da Ƙididdiga:

    AlloySheet/Plate/Trip/Coil

    Bututu / bututu mara nauyi

    welded gami tube/bututu

    Zobe/Bar/ Sanda

    Samfurin jabu

    Kayan aiki / Flange

    GB/T14992-2005.

    China Special Steel Limited kasuwar kasuwaGH3128 Nickel alloy Sheet/Plate/Trip/Coil/tube/Pipe/Ring/Bar/Rod/Forging/Fittings/Flange professional manufacturer and maroki. Idan kana da wani bayani game da GH3128 nickel gami sinadaran abun da ke ciki, Mechanical dukiya, yawa, zafi magani, narkewa batu, ko wani sabis, tuntuɓi da mu tallace-tallace tawagar.

     

    GH3044

    GH3044

    GH3044 ne m bayani ƙarfafa nickel tushen gamihadawan abu da iskar shaka, karkashin 900 ℃ high plasticity da matsakaici zafi tsanani, kuma yana da kyau kwarai hadawan abu da iskar shaka juriya da kuma yi na stamping, waldi tsari, da ya dace masana'antu a karkashin 900 ℃ da dogon lokacin da aikin jirgin sama kaddamar da babban konewa jam'iyya da afterburner sassa da zafi. rufi allo, jagora vane, wadata da iri farantin, bel, waya, tubes, sanduna da madauwari guda, da dai sauransu

    GH3044 alloy sinadaran abun da ke ciki:

    C%

    S%

    Cr%

    Mo%

    Ku%

    Ni%

    Mn%

    P%

    Al

    Ti

    ≤0.12

    ≤0.013

    23.5 ~ 26.5

    ≤1.50

    0.5 zuwa 1.0

    35.0 ~ 40.0

    ≤0.50

    ≤0.013

    ≤0.50

    0.30 ~ 0.70

    A resistivity na daban-daban zafin jiki

    θ/ ℃ 20 100 200 300 400 500 600 700 800

    ρ/ (10-6Ω.m)

    20

    1.099

    1.108

    1.117

    1.117

    1.153

    1.135

    1.126

    1.126

    GH3044 bayan-burners gami da aka yi amfani da su don yin ɗakin konewar injin jirgin sama da tsarin stamping da tsarin walda da shigarwa, catheters da jagorar vane da sauran abubuwan haɗin gwiwa.

    Ƙarfe na JW yana adana fiye da tan 10,000 mai zafi da naman sanyiGH3044 karfea stock kowane wata. Za mu iya saduwa da abokin ciniki ta kowace bukata yawa. Dangane da waɗannan tushen hannun jari, masana'antar fa'idarmu ta bazu cikin tsarin ƙarfe kamar: yankan (kowane girman da kowane nau'i) hakowa, walda, niƙa, injina da tsarin ƙarfe.

    Hakanan muna da ƙungiyar dabaru masu inganci waɗanda ke tabbatar da lokacin isar da sauri da jigilar kaya. Duk da haka dai, idan kuna son nemo mai yin birgima mai zafi da sanyi na GH3044 mai ba da ƙarfe, mai yin birgima mai zafi da sanyi mai GH3044 mai masana'anta, mai yin birgima mai sanyi da sanyi.GH3044 mai fitar da karfe, don Allah a tuntuɓi ƙungiyar tallace-tallace na JW karfe. Za mu ba ku GH3044 farashin farashi mai zafi da sanyi mai zafi, zafi mai zafi da sanyi GH3044 mai kyau mai kyau da mafi kyawun sabis daga gare mu.

     

     

     


  • Na baya:
  • Na gaba:

  • Matsayin Material

    Kayan abu ASTM A240 Standard 201, 304 304L 304H 309S 309H 310S 310H 316 316H 316L 316Ti 317 317L 321 321H 347 347H 409 4104 30S
    ASTM A480 Standard 302, s30215, s30452, s30615, 308, 309, 309Cb, 310, 310Cb, S32615, S33228, S38100, 304H, 309H, 316H, 309H, 316H, 309H, 321H,347H, 348H, S31060, N08811, N08020, N08367, N08810, N08904, N08926, S31277, S20161, S30600, S30601, S312S3026 S32654, S32053, S31727, S33228, S34565, S35315, S31200, S31803, S32001, S32550, S31260, S32003, S32101, S332205, S32520, S32750, S32760, S32900, S32906, S32950, ​​S32974
    JIS 4304-2005 Standard SUS301L, SUS301J1, SUS302, SUS304, SUS304L, SUS316/316L, SUS309S, SUS310S, 3SUS21L, SUS347, SUS410L, SUS430  
    JIS G4305 Standard SUS301, SUS301L, SUS301J1, SUS302B, SUS304, SUS304Cu, SUS304L, SUS304N1, SUS304N2, SUS304LN, SUS304J1, SUSJ2, SUS305, SUS309S2S SUS315J1, SUS315J2, SUS316, SUS316L, SUS316N, SUS316LN, SUS316Ti, SUS316J1, SUS316J1L, SUS317, SUS317L, SUS317LN, SUS3131JUS SUS890L, SUS321, SUS347, SUSXM7, SUSXM15J1, SUS329J1, SUS329J3L, SUS329J4L, SUS405, SUS410L, SUS429, SUS430, SUS430LX, SUS430LX, SUS43SUS40 SUS436J1L, SUS444, SUS445J1, SUS445J2, SUS447J1, SUSXM27, SUS403, SUS410, SUS410S, SUS420J1

    Ƙayyadaddun samfur

    Gama Kauri Halaye Aikace-aikace
    Na 1 3.0mm ~ 50.0mm An gama da zafi-birgima, annealing da pickling, halin da fari pickled surface Chemical masana'antu kayan aiki, Masana'antu tankuna
    Na 2B 0.3mm ~ 6.0mm An gama shi da maganin zafi, zazzagewa bayan mirgina sanyi, sannan layin wucewar fata ya zama mafi haske da santsi Gabaɗaya Aikace-aikacen Medical Instruments, Tableware
    No. BA (Bright Annealed) 0.5mm ~ 2.0mm Maganin zafi mai haske bayan mirgina sanyi Kayan dafa abinci, kayan dafa abinci, manufar gine-gine
    Na 4 0.4mm ~ 3.0mm Goge tare da lamba 150 zuwa lamba 180 abrasives. Mafi mashahuri ƙare Madara & Wuraren sarrafa Abinci, Kayayyakin Asibiti, Baho
    Na 8 0.5mm ~ 2.0mm Filaye mai kama da madubi ta hanyar gogewa tare da mafi kyawun abrasives sama da raga 800 Reflector, madubi, ciki- waje ado don gini
    HL (Layin Gashi) 0.4mm ~ 3.0mm An gama ta hanyar ci gaba da goge baki Manufofin gine-gine, escalators, motocin kayan abinci

    Haɗin Sinadari

    Daraja

    C

    Si

    Mn

    P

    S

    Cr

    Ni

    Mo

    Ti

    N

    Cu

    Nb

    201

    ≤0.15

    ≤1.0

    5.50-7.50

    ≤0.05

    ≤0.03

    16.00-18.00

    3.50-5.50

    -

    -

    0.05-0.25

    -

    -

    202

    ≤0.15

    ≤1.0

    7.50-10.00

    ≤0.05

    ≤0.03

    17.00-19.00

    4.00-6.00

    -

    -

    0.05-0.25

    -

    -

    301

    ≤0.15

    ≤1.0

    ≤2.0

    ≤0.045

    ≤0.03

    16.00-18.00

    6.00-8.00

    -

    -

    ≤0.1

    -

    -

    302

    ≤0.15

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    17.00-19.00

    8.00-10.00

    -

    -

    ≤0.1

    -

    -

    303

    ≤0.15

    ≤1.0

    ≤2.0

    ≤0.2

    0.15

    17.00-19.00

    8.00-10.00

    ≤0.6

    -

    ≤0.1

    -

    -

    304

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    17.00-19.00

    8.00-10.00

    -

    -

    -

    -

    -

    304l

    ≤0.03

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    18.00-20.00

    8.00-10.00

    -

    -

    -

    -

    -

    304H

    0.04-0.1

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    18.00-20.00

    8.00-10.00

    -

    -

    -

    -

    -

    304N

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    18.00-20.00

    8.00-10.00

    -

    -

    0.10-0.16

    -

    -

    304J1

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    18.00-20.00

    6.00-9.00

    -

    -

    -

    1.00-3.00

    -

    305

    ≤0.12

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    17.00-19.00

    10.50-13.00

    -

    -

    -

    -

    -

    309S

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    22.00-24.00

    12.00-15.00

    -

    -

    -

    -

    -

    310S

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    24.00-26.00

    19.00-22.00

    -

    -

    -

    -

    -

    316

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    16.00-18.00

    10.00-14.00

    2.00-3.00

    -

    -

    -

    -

    316l

    ≤0.03

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    16.00-18.00

    12.00-15.00

    2.00-3.00

    -

    -

    -

    -

    316H

    ≤0.1

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    16.00-18.00

    10.00-14.00

    2.00-3.00

    -

    -

    -

    -

    316N

    ≤0.03

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    16.00-18.00

    10.00-14.00

    2.00-3.00

    -

    0.10-0.16

    -

    -

    316 Ti

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    16.00-19.00

    11.00-14.00

    2.00-3.00

    ≥5C

    -

    -

    -

    317l

    ≤0.03

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    18.00-20.00

    11.00-15.00

    3.00-4.00

    -

    -

    -

    -

    321

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    17.00-19.00

    9.00-12.00

    -

    5C-0.7

    -

    -

    -

    347

    ≤0.08

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    17.00-19.00

    9.00-12.00

    -

    -

    -

    -

    10C-1.10

    347H

    ≤0.1

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    17.00-19.00

    9.00-12.00

    -

    -

    -

    -

    8C-1.10

    2205

    ≤0.03

    ≤1.0

    ≤2.0

    ≤0.035

    ≤0.03

    21.00-24.00

    4.50-6.50

    2.50-3.50

    -

    0.08-0.20

    -

    -

    2507

    ≤0.03

    ≤0.8

    ≤1.2

    ≤0.035

    ≤0.02

    24.00-26.00

    6.00-8.00

    3.00-5.00

    -

    0.24-0.32

    -

    -

    904l

    ≤0.02

    ≤1.0

    ≤2.0

    ≤0.045

    ≤0.03

    19.00-23.00

    23.00-28.00

    4.00-5.00

    -

    -

    1.00-2.00

    -

    C276

    ≤0.02

    ≤0.05

    ≤1.0

    -

    -

    14.00-16.50

    Sauran

    -

    -

    -

    -

    -

    Monel400

    ≤0.3

    ≤0.5

    ≤2.0

    -

    ≤0.024

    -

    ≥63

    -

    -

    -

    28-34

    -

    409l

    ≤0.03

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    17.00-19.00

    -

    -

    -

    -

    -

    -

    410

    ≤0.15

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    11.50-13.50

    -

    -

    -

    -

    -

    -

    410l

    ≤0.03

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    11.50-13.50

    -

    -

    -

    -

    -

    -

    420J1

    0.16-0.25

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    12.00-14.00

    -

    -

    -

    -

    -

    -

    420J2

    0.26-0.40

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    12.00-14.00

    -

    -

    -

    -

    -

    -

    430

    ≤0.12

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    16.00-18.00

    -

    -

    -

    -

    -

    -

    436l

    ≤0.025

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    16.00-19.00

    -

    -

    -

    -

    -

    -

    439

    ≤0.03

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    16.00-18.00

    -

    -

    -

    -

    -

    -

    440A

    0.60-0.75

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    16.00-18.00

    -

    ≤0.75

    -

    -

    -

    -

    440B

    0.75-0.95

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    16.00-18.00

    -

    ≤0.75

    -

    -

    -

    -

    440C

    0.95-1.2

    ≤1.0

    ≤1.0

    ≤0.035

    ≤0.03

    16.00-18.00

    -

    ≤0.75

    -

    -

    -

    -

    441

    ≤0.03

    0.2-0.8

    ≤0.7

    ≤0.03

    ≤0.015

    17.50-18.50

    -

    ≤0.5

    0.1-0.5

    ≤0.025

    -

    0.3+3C-0.9

    Mukunsa samfuran bakin karfe tare da takarda anti-tsatsa da zoben karfe don hana lalacewa.

    Ana yiwa lakabin tantancewa bisa ga ƙayyadaddun ƙayyadaddun ƙayyadaddun bayanai ko umarnin abokin ciniki.

    Ana samun fakiti na musamman gwargwadon buƙatun abokin ciniki.

    Kunshin Bakin Karfe Nada

    cepheus bakin karfe nada (1)

    cepheus bakin karfe nada (2)

     

    Bakin Karfe Sheet / Kunshin Bakin Karfe

    fakitin bakin karfe cepheus (3)

    cepheus bakin karfe farantin karfe 1_副本

     

    Kunshin Bakin Karfe Strip

    kunshin bakin karfe na cepheus (5)

    Kunshin jigilar kaya

    Jirgin ruwan Cepheus Bakin Karfe (1)

    Jirgin ruwan Cepheus Bakin Karfe (2)

    Jirgin ruwan Cepheus Bakin Karfe (3)

    Kamfaninmu yana dogara ne a Wuxi, yana tara birnin masana'antu bakin karfe a kasar Sin.

    Mun ƙware a cikin bakin coils, zanen gado da faranti, bakin karfe da bututu da kayan aiki, bututun bakin karfe, da samfuran aluminum da samfuran tagulla.

    Abokan cinikinmu daga Turai, Amurka, Gabas ta Tsakiya, Afirka da kudu maso gabashin Asiya sun yaba da samfuranmu. Za mu bayar da m kayayyakin da m sabis ga abokan ciniki.

    Bakin Karfe Grade: 201, 202, 202cu, 204, 204cu, 303, 304, 304L, 308, 308L, 309, 309s, 310, 310s, 316, 316, 3, 7 420, 430, 430F, 440, 440c,

    Alloy Grade: Monel, Inconel, Hastolley, Duplex, Super Duplex, Titanium, Tantalum, High Speed ​​Karfe, M Karfe, Aluminium, Alloy Karfe, Carbon Karfe, Musamman Nickel Alloys

     

    A cikin nau'i na: Zagaye Bars, Bars Square, Hexagonal Bars, Flat Bars, Angles, Channels, Profiles, Wayoyi, Wayoyin Waya, Sheets, Faranti, Bututu maras kyau, ERW Pipes, Flanges, Fittings, da dai sauransu.

    Wuxi cepheus bakin karfe (1)

     

    Wuxi cepheus bakin karfe (5)

    Wuxi cepheus bakin karfe (4)

    Wuxi cepheus bakin karfe (3)

     

    Wuxi cepheus bakin karfe (2)

     

    Q1: Menene bakin ciki?

    A: Bakin ƙarfe yana nufin babu alama a saman saman ƙarfe, ko nau'in ƙarfe wanda iska ko ruwa bai lalace ba kuma wanda baya canza launi, mara tabo, juriya ga tabo, tsatsa, lalatar tasirin sinadarai.

    Q2: Shin bakin karfe yana nufin babu tsatsa?

    A: A'a, bakin karfe yana nufin ba sauƙin samun tabo ko tsatsa ba, yana da ikon iya tsayayya da tabo, tsatsa da lalata.

    Q3: Kuna samar da zanen gado na bakin karfe?

    A: Ee, muna samar da nau'ikan nau'ikan nau'ikan zanen karfe, tare da kauri daga 0.3-3.0mm. kuma a lokuta daban-daban.

    Q4: Kuna yarda da yanke zuwa tsayin sabis?

    A: Tabbas, gamsuwar abokin ciniki shine babban fifikonmu.

    Q5: Idan ina da ƙaramin oda, kuna karɓar ƙaramin oda?

    A: Ba matsala ba, damuwar ku ita ce damuwarmu, ana karɓar ƙananan yawa.

    Q6: Ta yaya za ku iya tabbatar da ingancin samfurin ku?

    A: Na farko, tun daga farko, mun riga mun aiwatar da ruhi zuwa tunaninsu, wato inganci ita ce rayuwa, kwararrun ma’aikatanmu da ma’aikatanmu za su bi kowane mataki har kayan sun cika da kyau kuma a fitar da su.

    Q7: Za ku shirya samfuran?

    A: Masu sana'a suna yin ƙwararrun ƙwararrun ƙwararrun ƙwararrun ƙwararrun ƙwararrun ƙwararrun ƙwararrun, muna da nau'ikan tattarawa daban-daban na zaɓi ga abokan ciniki, ɗayan tattalin arziki ko mafi kyau.

    Q8: Menene kuke buƙatar sani daga abokin ciniki kafin ingantaccen zance?

    A: Don ingantacciyar magana, muna buƙatar sanin daraja, kauri, girman, ƙarewar saman, launi da adadin odar ku, da kuma maƙasudin kayan. Za a buƙaci ƙarin bayanin samfur na musamman, kamar zane, shimfidawa da tsari. Sa'an nan kuma za mu ba da magana mai gasa tare da bayanin da ke sama.

    Q9: Wane irin wa'adin biyan kuɗi kuka karɓa?

    A: Mun yarda da T/T, West union, L/C.

    Q10: Idan wannan ƙaramin oda ne, za ku isar da kayan ga wakilinmu?

    A: Ee, an haife mu ne don magance matsalolin abokan cinikinmu, za mu sami kayan cikin aminci zuwa ɗakin ajiyar wakilin ku kuma mu aiko muku da hotuna.

    Q11: Shin kuna yin lebur kawai? Ina so in yi ƙage don sabon aikina.

    A: A'a, mu yafi samar da bakin karfe lebur takardar surface jiyya, a lokaci guda, mu tsirar musamman karfe ƙãre samfurin kamar yadda ta abokin ciniki ta zane da kuma shirin, mu m zai kula da sauran.

    Q12: Katuna nawa kuka riga kuka fitar dashi?
    A: Ana fitar dashi zuwa kasashe sama da 50 musamman daga Amurka, Rasha, UK, Kuwait, Masar, Iran,
    Turkiyya, Jordan, da dai sauransu.
    Q13: Ta yaya zan iya samun wasu samfurori?
    A: Ƙananan samfurori a cikin kantin sayar da kayayyaki kuma suna iya samar da samfurori kyauta. Catalgue yana samuwa, mafi yawa
    alamu muna da shirye samfurori a hannun jari. Samfurori na musamman zasu ɗauki kimanin kwanaki 5-7.
    Q14: Menene isarwa?
    A: Misalin odar lokacin isarwa shine kwanaki 5-7. Umarnin kwantena kusan kwanaki 15-20 ne.

    Q15: Menene aikace-aikacen game da samfuran ku?
    A: 1.elevator kofa/ cabin ko da bangon gefen escalator.
    2.Rufe bango ciki ko waje dakin taro/gidan cin abinci.
    3.Facade a lokacin da ake cladding a kan wani abu, kamar ginshiƙai a cikin harabar gidan.
    4.Rufi a babban kanti. 5.Ado zana a wasu wuraren nishadi.
    Q16: Har yaushe Zaku iya Ba da garantin Wannan samfur/Kammala?
    A: Garanti mai launi fiye da shekaru 10. Takaddun ingancin kayan asali na iya
    a bayar.

    Samfura masu dangantaka