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维普资讯httpwwwcqvipcomr
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ISSN1007．6417，Vo1．5，No．4Dec．2001，PP326～330r
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I
flue
ceofDiffere
tSurfaceTreatme
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ItsThermalFatigueBehaviorsr
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UddeholmToogi
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AbstractThermalfatiguechecki
gisthege
eralfailureofhotworkdiesteels，whichisrelativewiththestructuresa
dpropertiesofr
r
thesteelsa
dthestressalter
atedduri
gtheemployme
t．TheUddeholmtestmethodo
thermalfatigueisusedtocomparetheber
r
haviorsofdiffere．tsamples．whicharetreatedw1thplasma
irtidi
g、plasmasulfurcarbe
irtidi
g、bero
izi
gor
ottreatedTher
r
resultsshowthathte
itridi
gimprovesthethermalfatiguepropertyofthetoolsteel，whiletheplasmasulfurcarbo
itridi
ga
dther
r
boro
izi
gimpairthepropertyThemecha
ismsarei
ducedasfollows．Byi
creasi
gthehard
essa
dcha
gi
ghtestressdisrtibur
r
tio
i
thesurfacelayer，surfacetreatme
tca
decreasethephsticdeformatio
a
dthete
silestressduri
gthecycli
gTherefore，r
r
thege
eratio
a
dgrowthofthecracksarerestrai
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teu北hessdecli
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dtheexpa
di
gcoefficie
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des；htelattercha
gecausedhtesrte
ghte
i
gofhtete
silea
dcompressiver
r
srtessduri
gthecycli
gThushteresista
ce加therma1fatigueisweake
ed．Whetheror
otthesurfacerteatme
tisfavortotherr
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maIfatigueoftooIsteelsrelieso
whichfac加risdomi
a
t．r
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Keywordshtermalfatigue，hotworkdie．surfacetraetme
tr
r
twee
thesurfacelayera
dthecore【．Althoughr
1I
troductio
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therearealotofsuccessfulappliactio
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Withthei
creasi
goflightmetalsa
dtheiralloystreati
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gthelifetimeofdies一，r
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emp1oyedasautomobileparts，theexpe
sivediecasthowever，itsmecha
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gdiesystemsbecomemorecomplexa
dhavebee
thema
yfactorsacti
go
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dthevarietyofdier
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usedmorefreque
tly，whichIeadtotherequireme
tsfatigue．Thesurfacetreatme
tissometimes
egativer
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oflo
gerlifeofdies．Themai
failuretypesofdieotdies’lifetime．sothereareosmediecasti
gdiesr
r
casti
gdiesareheatchecki
g、grosscrack、molte
employedwithoutsurfacetreati
g．Thermalfatiguer
r
metaIcorrosio
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derosio
l】1．Surfacetreatme
ts，behaviorsofH13stee1afterdiffere
ttreatme
tssuchr
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especiallythr
osewhichcouldcreateaco
ti
uouscomasplasma
itridi
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