Yemhando yepamusoro mbizha ndiyo hwaro hwekugadzira emhando yepamusoro fasteners. Nekudaro, zvigadzirwa zvakawanda zvevagadziri vefastener zvichave nekutsemuka. Sei izvi zvichiitika?

Parizvino, zvinowanzoitika zvekabhoni structural steel wire rods zvinopiwa nemidziyo yesimbi yepamba ndeye φ 5.5- φ 45, iyo yakakura yakakura ndeye φ 6.5- φ 30. Kune njodzi dzakawanda dzehutano dzinokonzerwa nekuparadzaniswa kwephosphorus, zvakadai se phosphorus segregation ye tsvimbo duku yewaya nebhari. Pesvedzero yekupatsanurwa kwephosphorous uye kuongororwa kwekuumbwa kwekutsemuka kunounzwa pazasi kuti itariswe. Kuwedzerwa kwephosphorous musimbi kabhoni chikamu dhizaini kunovhara zvinoenderana neiyo austenite chikamu dunhu uye zvisingadzivisiki kuwedzera chinhambwe pakati peiyo solidus uye liquidus. Kana phosphorous ine simbi yakatonhodzwa kubva pamvura kuenda pakasimba, inoda kupinda nepakati petembiricha yakakura.

Kupararira kwe phosphorus musimbi kunononoka, uye simbi yakanyungudutswa ine yakakwirira phosphorus concentration (yakaderera melting point) izere neyokutanga yakaomeswa dendrites, iyo inotungamirira phosphorus segregation. Kune zvigadzirwa zvinowanzove nekutsemuka panguva yekutonhora yekubikira kana kutonhora extrusion, iyo metallographic kuongororwa uye kuongororwa kunoratidza kuti ferrite uye pearlite zvakagoverwa mumitsetse, uye kune chena bhendi ferrite mumatrix. Kune inopindirana mwenje grey sulfide inosanganisirwa nzvimbo pane yakasungwa ferrite matrix. Iyo yakasungirirwa chimiro che sulfide inonzi "ghost line" nekuda kwekuparadzanisa sulfide.
Chikonzero ndechekuti iyo nzvimbo ine yakakomba phosphorus segregation inopa chena inopenya nzvimbo munzvimbo yekupfumisa phosphorus. Mune inoenderera mberi yekukanda slab, nekuda kwehuwandu hwe phosphorus munzvimbo chena, iyo columnar makristasi akapfuma mu phosphorus concentrate, kuderedza phosphorus content. Kana billet raoma, austenite dendrites inotanga kupatsanurwa kubva kusimbi yakanyungudutswa. Iyo phosphorus nesarufa iri mumadendrite aya inoderedzwa, asi simbi yakanyungudutswa pakupedzisira ine phosphorus nesarufa zvinhu. Inoomesa pakati pemasanhu edendrite nekuti phosphorus nesarufa zvinhu zvakakwirira. Panguva ino, sulfide inoumbwa, uye phosphorus inonyungudutswa mumatrix. Nokuti phosphorus uye sulfur zvinhu zvakakwirira, sulfide inoumbwa pano, uye phosphorus inonyungudutswa mumatrix. Nokudaro, Nekuda kwehuwandu hwephosphorus uye sulfur elements, carbon content mu phosphorus solid solution yakakwira. Pamativi ese maviri ebhandi rekabhoni, ndiko kuti, pamativi ese enzvimbo yekupfumisa phosphorus, bhandi refu uye rakamanikana rinopindirana pearlite rakafanana nebhanhire jena referrite rinoumbwa, uye pedyo neakajairika tishu akaparadzaniswa. Pasi pekupisa kwekupisa, billet inoenda kune nzira yekugadzirisa pakati pemashafts, nokuti bhanhire referrite rine phosphorus yakakwira, kureva, phosphorus segregation inotungamira mukuumbwa kweiyo inorema yakakura yakajeka inopenya ferrite bhandi chimiro neyakajeka inopenya ferrite bhandi chimiro. . Zvinogona kuoneka kuti kune zvakare akareruka grey sulfide mitsetse mune yakafara inopenya ferrite bhandi, iyo inogovaniswa netambo refu ye sulfide rich phosphorus ferrite belt, iyo yatinowanzo kudaidza kuti "ghost line". (Ona Mufananidzo 1-2)

Flange Bolt

Mukupisa kunopisa, chero bedzi kune phosphorus segregation, hazvibviri kuwana yunifomu microstructure. Zvinotonyanya kukosha, nekuti kupatsanurwa kwephosphorous kwakagadzira "ghost line" chimiro, zvichange zvisingadzivisiki kuderedza michina yezvinhu. Phosphorus segregation mu carbon bonded steel yakajairika, asi degree rayo rakasiyana. Yakanyanya phosphorus segregation ("ghost line" chimiro) inokonzeresa zvakanyanya kuipa pasimbi. Zviripachena, kupatsanurwa kwakanyanya kwephosphorous ndiyo honzeri yekutonhora musoro kutsemuka. Nekuti iyo phosphorus yemukati mune dzakasiyana tsanga dzesimbi yakasiyana, zvinhu zvine masimba akasiyana uye kuoma. Kune rumwe rutivi, inoita kuti zvinhu zvibudise kushushikana kwemukati, izvo zvichaita kuti zvinhu zvive nyore kuputika. Mune zvigadzirwa zvine "ghost line" chimiro, imhaka chaiyo nekuda kwekuderera kwekuoma, simba, kureba mushure mekutsemuka uye kudzikiswa kwenzvimbo, kunyanya kuderera kwekuoma kwesimba, kuti iyo phosphorus yemukati mumidziyo ine hukama hukuru nechimiro uye. zvinhu zvesimbi.
Mu "ghost line" tissue iri pakati pemunda wekuona, yakawanda yakaonda, chiedza grey sulfide yakaonekwa ne metallography. Izvo zvisiri-metallic inclusions musimbi yezvimiro zvinonyanya kuvepo muchimiro che oxides uye sulfides. Zvinoenderana neGB/T10561-2005 Standard Classification Diagram yeZviri mukati meIsiri simbi Inclusions muSimbi, iyo sulfide yemukati yeClass B inclusions ndeye 2.5 kana pamusoro. Nonmetallic inclusions ndiyo inogona kuparuka sosi. Kuvapo kwayo kuchakuvadza zvakanyanya kuenderera uye kusimba kwechimiro chesimbi, nokudaro kuderedza zvakanyanya intergranular simba.
Zvinofungidzirwa kuti sulfide muchimiro chemukati "ghost line" yesimbi ndiyo inonyanya kuputika chikamu. Nokudaro, nhamba huru yezvigadziro zvakaputika mumusoro unotonhora uye kupisa kupisa kunodzima panzvimbo yekugadzira, iyo yakakonzerwa nenhamba yakawanda yechiedza grey refu sulfides. Iri jira risingarukwa rakaparadza kuenderera kwesimbi zvinhu uye rakawedzera njodzi yekupisa kurapwa. "Ghost line" haigone kubviswa nekujairira uye nedzimwe nzira, uye zvinhu zvetsvina zvinozodzorwa zvakasimba zvisati zvanyungudutswa kana mbishi kupinda muchirimwa. Zvinoenderana nekuumbwa uye deformability, isiri-metallic inclusions yakakamurwa kuita alumina (mhando A) silicate (rudzi C) uye spherical oxide (rudzi D). Chitarisiko chayo chichagura kuenderera mberi kwesimbi uye kuva makomba kana kutsemuka mushure mekusvuura, izvo zviri nyore kugadzira mitswe panguva yekutonhora musoro uye kukonzera kushushikana mupfungwa panguva yekupisa kurapwa, nokudaro zvichikonzera kudzima makatsemuka. Nokudaro, kwete-metallic inclusions inofanira kunyatsodzorwa. Ikozvino Structural Carbon Structural Steels GB/T700-2006 uye GB T699-2016 High Quality Carbon Steels inoisa mberi zvinodiwa kune zvisiri-metallic inclusions. Kune zvikamu zvakakosha, zvinowanzoita A, B, C mhando dzakakasharara dzakateedzana, yakanaka yakatevedzana haina kupfuura 1.5, D, Ds mhando coarse system uye level 2 haina kupfuura level 2.

Hebei Chengyi Engineering Materials Co., Ltd. ikambani ine makore makumi maviri nerimwe ekugadzira fastener uye ruzivo rwekutengesa. Mafasteners edu anoshandisa emhando yepamusoro zviwanikwa, kugadzirwa kwepamberi uye tekinoroji yekugadzira, uye yakakwana manejimendi system kuona chigadzirwa chemhando. Kana iwe uchida kutenga fasteners, tapota taura nesu.