Austempered Ductile Iron - ADI Castings

Austempered ductile iron, inozivikanwawo seADI, inoreva iyo ductile cast iron mushure mekuita austenitizing ductile iron (850 ℃-950 ℃) uye nekukasira kuiisa mubhavhu remunyu (232 ℃-450 ℃) yekushandurwa isothermal. Mukuwedzera, nekuwedzera kwehuwandu hwakakwana hweCu, Ni, Mo uye zvimwe zvinhu, austempered austenitic ductile iron inogonawo kuwanikwa pasi pemamiriro ekutonhora anoramba achitonhora.

Austempered ductile ironcastingsvane zvinhu zvakanakisa zvemuchina, uye huremu hweyuniti yekusimba kwegoho ndiyo idiki. Kuwanikwa kwemagiredhi akasiyana eaustempered ductile iron kunoenderana nekupisa kwehutempering uye hakunei nechekuita nemakemikari. Kazhinji kutaura, kemikari yeaustempered ductile iron iri mumhando inotevera:
C: 3.5% -3.8%
Si: 2.4% -3.0%
Mn: ＜0.30%
P: <0.07%
S: <0.02%

Silicon chimwe chezvinhu zvakakosha zve austempered ductile iron. Silicon inodzivirira kuumbwa kweBainite carbides, nokudaro inobatsira pakuumbwa kweacicular ferrite. Kuwedzera iyo silicon yemukati inogona kuwedzera iko kuomarara kweiyo austempered ductile cast iron uye kuderedza kureba. Basa reManganese rine mativi maviri. Kune rumwe rutivi, inogona kuvandudza zvakanyanya kuoma; kune rumwe rutivi, Manganese inosimudzira kuumbwa kwecarbides uye inodzivisa isothermal shanduko panguva yekusimbisa maitiro. Nokudaro, kana nhamba ye graphite spheres yakaderera uye rusvingo rwakakura, kuparadzaniswa kwemanganese pamuganhu wezviyo kunokonzera shrinkage porosity, carbides uye kusagadzikana austenite mu ductile iron casting. Aya ma microstructure defects uye inhomogeneities anozoderedza machinability uye michina zvinhu. Nokudaro, huwandu hwemanganese hunofanira kudzorwa pasi pe3%.

Mukugadzirwa chaiko kwekukanda, kuitira kuti uwane yakagadzikana uye yemhando yepamusoro austemperedductile iron castings, pane mapoinzi maviri anoda kutariswa zvakanyanya:
1) Dzora chimiro che-as-cast ductile iron isati yarapwa isothermal. Iyo spheroidization rate inofanira kunge yakakwira kupfuura 80%. Nhamba ye graphite pheres inofanira kudarika 100 pa square millimeter. Mamwe mamiriro ezvinhu anosanganisira: kugadzikana kwemakemikari kuumbwa; kukanda kunofanira kunge kusina carbides, porosity uye inclusions; uye yakagadzikana pearlite/ferrite content ratio.
2) Sarudza iyo yakakodzera kupisa yekupisa yakatarwa zvinoenderana nekuumbwa uye se-kukanda chimiro che ductile iron, uye ita yakasimba uye yakagadzikana inoomesa kupisa kupisa maitiro.