Iimathiriyeli ezikrwada ezikumgangatho ophezulu zisisiseko sokuvelisa izibophelelo ezikumgangatho ophezulu.Nangona kunjalo, iimveliso ezininzi zabenzi be-fastener ziya kuba neentanda.Kutheni le nto isenzeka?

Okwangoku, iinkcukacha eziqhelekileyo ze-carbon structural steel wire rods ezinikezelwa ngamashishini ensimbi yasekhaya φ 5.5- φ 45, uluhlu oluvuthiweyo ngakumbi φ 6.5- φ 30. Kukho iingozi ezininzi zekhwalithi ezibangelwa ukuhlukana kwe-phosphorus, njengokuhlukana kwe-phosphorus intonga encinci yocingo kunye nebha.Impembelelo yokwahlula i-phosphorus kunye nohlalutyo lokubunjwa kokuqhekeka kwaziswa ngezantsi ukuze kubhengezwe.Ukongezwa kwe-phosphorus kwidayagram ye-iron carbon phase iya kuvala ngokuhambelanayo ummandla wesigaba se-austenite kwaye ngokuqinisekileyo ukwandisa umgama phakathi kwe-solidus kunye ne-liquid.Xa i-phosphorus equlethe intsimbi ipholile ukusuka kulwelo ukuya kwisiqina, kufuneka idlule kuluhlu olukhulu lobushushu.

Izinga lokusasazwa kwe-phosphorus kwintsimbi licotha, kwaye isinyithi esityhidiweyo esine-concentration ye-phosphorus ephezulu (indawo encibilikayo ephantsi) igcwele i-dendrites yokuqala eqiniweyo, ekhokelela ekuhlukaniseni i-phosphorus.Kwiimveliso ezihlala zineentanda ngexesha lokubanda okubandayo okanye i-extrusion ebandayo, uvavanyo lwe-metallographic kunye nohlalutyo lubonisa ukuba i-ferrite kunye ne-pearlite isasazwa ngemicu, kwaye kukho i-ferrite emhlophe ebhanti kwi-matrix.Kukho iizowuni eziqukwayo ezingwevu ezingwevu kwibhanti yeferrite matrix.Isakhiwo esibhandiweyo sesulfide sibizwa ngokuba "ngumgca wesiporho" ngenxa yokwahlulwa kwesulfide.
Isizathu sesokuba indawo enocalu-calulo olukhulu lwe-phosphorus ibonisa indawo emhlophe eqaqambileyo kwindawo yokutyebisa i-phosphorus.Kwi-slab eqhubekayo yokuphosa, ngenxa yomxholo we-phosphorus kwindawo emhlophe, i-columnar crystals ecebileyo kwi-phosphorus concentrate, inciphisa umxholo we-phosphorus.Xa i-billet iqina, i-austenite dendrites iqala ukuhlukana nentsimbi etyhidiweyo.I-phosphorus kunye nesulfure kwezi dendrites ziyancipha, kodwa ekugqibeleni intsimbi etyhidiweyo etyhidiweyo iqulethe i-phosphorus kunye ne-sulfur elements.Iqinisa phakathi kwee-ax ze-dendrite kuba i-phosphorus kunye ne-sulfure elementi ziphezulu.Ngeli xesha, i-sulfide yenziwa, kwaye i-phosphorus iyachithwa kwi-matrix.Ngenxa yokuba izinto ze-phosphorus kunye nesulfure ziphezulu, i-sulfide yenziwa apha, kwaye i-phosphorus iyachithwa kwi-matrix.Ngoko ke, Ngenxa yomxholo ophezulu we-phosphorus kunye ne-sulfure, umxholo wekhabhoni kwisisombululo esiqinileyo se-phosphorus siphezulu.Kumacala omabini ebhanti ye-carbonaceous, oko kukuthi, kumacala omabini ommandla wokutyebisa i-phosphorus, ibhanti elide kunye nelincinci elincinci le-pearlite elihambelana nebhanti elimhlophe le-ferrite lenziwa, kwaye izicubu eziqhelekileyo ezikufutshane ziyahlukana.Ngaphantsi koxinzelelo lokufudumeza, i-billet iya kwandiswa ukuya kwindlela yokucubungula phakathi kwee-shafts, kuba ibhanti ye-ferrite iqulethe i-phosphorus ephezulu, oko kukuthi, ulwahlulo lwe-phosphorus luya kukhokelela ekwakhiweni kwebhanti enzima ebanzi ekhanyayo kunye nesakhiwo sebhanti ebanzi ekhanyayo. .Kuya kubonakala ukuba kukho imicu engwevu yesulfide ekhanyayo kwibhanti ebanzi eqaqambileyo yeferrite, esasazwa ngomtya omde webhanti yeferrite etyebileyo yesulfide, esihlala siyibiza ngokuba "ngumgca wesiporho".(Jonga umfanekiso 1-2)

I-Flange Bolt

Kwinkqubo yokushisa eshushu, ngokude nje kukho ukuhlukana kwe-phosphorus, akunakwenzeka ukufumana i-microstructure efanayo.Okubaluleke ngakumbi, ngenxa yokuba ukuhlukana kwe-phosphorus kuye kwakha "umgca weghost" isakhiwo, ngokuqinisekileyo kuya kunciphisa iimpawu zomatshini wezinto eziphathekayo.Ukwahlukaniswa kwe-phosphorus kwintsimbi ye-carbon bonded kuqhelekile, kodwa idigri yayo yahlukile.Ukwahlula okunamandla kwe-phosphorus ("umgca weghost") kuya kubangela iziphumo ezibi kakhulu kwintsimbi.Ngokucacileyo, ulwahlulo olunzima lwe-phosphorus luyi-culprit ye-cold heading cracking.Ngenxa yokuba umxholo we-phosphorus kwiinkozo ezahlukeneyo zetsimbi zihlukile, izixhobo zinamandla ahlukeneyo kunye nobunzima.Ngakolunye uhlangothi, yenza ukuba izinto eziphathekayo zivelise uxinzelelo lwangaphakathi, oluya kwenza ukuba izinto eziphathekayo zilula.Kwimathiriyeli enesakhiwo "somgca wesiporho", kungenxa yokuncipha kobunzima, amandla, ubude emva kokwaphuka kunye nokuncipha kwendawo, ngakumbi ukuncipha kokuqina kwempembelelo, ukuba umxholo we-phosphorus kwizinto eziphathekayo unobudlelwane obukhulu kunye nesakhiwo kunye. iimpawu zentsimbi.
Kwi-tissue "yomgca weghost" ephakathi kwintsimi yombono, ubuninzi be-sulfide encinci, i-gray sulfide ifunyenwe nge-metallography.I-non-metallic inclusions kwi-structural steel inclusions ikhona ikakhulu kwifom ye-oxides kunye ne-sulfides.Ngokutsho kwe-GB/T10561-2005 iDiyagram yoHlelo oluQhelekileyo loMxholo we-Non Metallic Inclusions kwi-Steel, umxholo we-sulfide we-Class B inclusions yi-2.5 okanye ngaphezulu.Ukufakwa kwe-nonmetallic ngumthombo onokwenzeka wokuqhekeka.Ubukho bayo buya kulimaza kakhulu ukuqhubeka kunye nokuqina kwesakhiwo sensimbi, ngaloo ndlela kunciphisa kakhulu amandla e-intergranular.
Kucatshangelwa ukuba i-sulfide kwisakhiwo sangaphakathi "umgca weghost" yensimbi iyona nxalenye elula kakhulu eqhekekileyo.Ngoko ke, inani elikhulu le-fasteners liqhekezekile kwisihloko esibandayo kunye nokucima unyango lobushushu kwindawo yokuvelisa, eyabangelwa inani elikhulu le-sulfide grey ekhanyayo.Eli laphu elingaphothiweyo latshabalalisa ukuqhubeka kweempawu zetsimbi kwaye kwandisa umngcipheko wonyango lobushushu."Umgca wesiporho" awunakususwa ngokusetyenziswa kwesiqhelo kunye nezinye iindlela, kwaye izinto ezingacocekanga ziya kulawulwa ngokungqongqo phambi kokunyibilikiswa okanye imathiriyeli ekrwada ingene kwisityalo.Ngokutsho kokubunjwa kunye nokukhubazeka, i-non-metallic inclusions ihlukaniswe ibe yi-alumina (uhlobo A) i-silicate (uhlobo C) kunye ne-spherical oxide (uhlobo D).Ukubonakala kwayo kuya kunqumla ukuqhubeka kwetsimbi kwaye ibe yimigodi okanye iintanda emva kokuqhawula, okulula ukwenza iintanda ngexesha lokubanda kwaye kubangele uxinzelelo lwexinzelelo ngexesha lonyango lobushushu, ngaloo ndlela kubangele ukucima iintanda.Ngoko ke, ukubandakanywa okungezona isinyithi kufuneka kulawulwe ngokungqongqo.I-Structural Carbon Structural Steels yangoku GB/T700-2006 kunye ne-GB T699-2016 High Quality Carbon Steels ibeka phambili iimfuno zokubandakanywa okungezona isinyithi.Kwiindawo ezibalulekileyo, ngokuqhelekileyo i-A, B, i-C yodidi lwe-coarse series, i-fine series ayikho ngaphezu kwe-1.5, D, i-Ds uhlobo lwenkqubo enqabileyo kunye nenqanaba lesi-2 alikho ngaphezu kwe-2.

I-Hebei Chengyi Engineering Materials Co., Ltd. yinkampani eneminyaka engama-21 yokuvelisa i-fastener kunye namava okuthengisa.Iziqhoboshi zethu zisebenzisa izinto ezikumgangatho ophezulu ekrwada, imveliso ephezulu kunye neteknoloji yokuvelisa, kunye nenkqubo yolawulo egqibeleleyo yokuqinisekisa umgangatho wemveliso.Ukuba unomdla ekuthengeni i-fasteners, nceda uqhagamshelane nathi.