Babban ingancin albarkatun kasa sune tushen samar da kayan ɗamara masu inganci. Duk da haka, yawancin samfuran masu ƙera fastener za su sami fasa. Me yasa hakan ke faruwa?

A halin yanzu, ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙaƙƙarfan sandunan ƙarfe na tsarin ƙarfe na ƙarfe na cikin gida suna samarwa shine φ 5.5- φ 45, mafi girman kewayon φ 6.5- φ 30. Akwai hatsarori masu inganci da yawa da ke haifar da rabuwar phosphorus, kamar rabewar phosphorus. karamin sandar waya da mashaya. An gabatar da tasirin rarrabuwar phosphorus da kuma nazarin samuwar fashewa a ƙasa don tunani. Bugu da ƙari na phosphorus a cikin zane-zanen lokaci na ƙarfe na carbon zai daidai da rufe yankin austenite kuma babu makawa ya ƙara tazara tsakanin solidus da liquidus. Lokacin da aka sanyaya phosphorus mai ɗauke da ƙarfe daga ruwa zuwa ƙarfi, yana buƙatar wucewa ta babban kewayon zafin jiki.

Yawan yaɗuwar phosphorus a cikin ƙarfe yana jinkirin, kuma narkakken ƙarfe tare da babban abun ciki na phosphorus (ƙananan narkewa) yana cike da ƙarfafawar dendrites na farko, wanda ke haifar da rabuwar phosphorus. Don samfuran da galibi suna da fashe yayin ƙirƙira sanyi ko sanyi mai sanyi, binciken metallographic da bincike ya nuna cewa ferrite da pearlite ana rarraba su cikin tsiri, kuma akwai farin banded ferrite a cikin matrix. Akwai yankuna hada da sulfide mai haske mai tsaka-tsaki akan matrix ferrite. Tsarin banded ɗin sulfide ana kiransa “layin fatalwa” saboda rarrabuwar sulfide.
Dalili kuwa shi ne yankin da ke da tsananin ɓarkewar phosphorus yana ba da farin yanki mai haske a cikin yankin wadatar phosphorus. A cikin simintin simintin gyare-gyare na ci gaba, saboda babban abun ciki na phosphorus a cikin farin yanki, lu'ulu'u na columnar masu arziki a cikin phosphorus suna mayar da hankali, rage abun ciki na phosphorus. Lokacin da billet ɗin ya ƙarfafa, austenite dendrites an fara raba su da narkakken ƙarfe. Phosphorus da sulfur a cikin waɗannan dendrites an rage su, amma a ƙarshe ƙarfafa narkakkar karfe yana dauke da sinadarin phosphorus da sulfur. Yana ƙarfafa tsakanin gatari dendrite saboda abubuwan phosphorus da sulfur suna da girma. A wannan lokacin, an kafa sulfide, kuma an narkar da phosphorus a cikin matrix. Saboda abubuwan phosphorus da sulfur suna da girma, ana samar da sulfide a nan, kuma an narkar da phosphorus a cikin matrix. Saboda haka, saboda babban abun ciki na phosphorus da sulfur abubuwa, da carbon abun ciki a cikin phosphorus m bayani ne high. A ɓangarorin biyu na bel na carbonaceous, wato, a ɓangarorin biyu na yankin wadatar phosphorus, bel ɗin lu'u-lu'u mai tsayi da ƙunci mai ɗanɗano daidai yake da bel ɗin farin ferrite, kuma kyallen da ke kusa da su sun rabu. A karkashin matsa lamba na dumama, billet ɗin zai ƙara zuwa hanyar sarrafawa tsakanin sandunan, saboda bel ɗin ferrite ya ƙunshi babban phosphorus, wato, rarrabuwar phosphorus zai haifar da samuwar babban bel mai haske mai haske tare da tsarin bel mai haske mai haske. . Ana iya ganin cewa akwai maɗaurin sulphide masu launin toka mai haske a cikin bel ɗin ferrite mai faɗi mai haske, wanda aka rarraba tare da dogon tsiri na bel ɗin sulfide mai arzikin phosphorus ferrite, wanda yawanci muke kira "layin fatalwa". (Dubi Hoto na 1-2)

Flange Bolt

A cikin yanayin zafi mai zafi, idan dai akwai rabe-raben phosphorus, ba shi yiwuwa a sami microstructure na uniform. Mafi mahimmanci, saboda rarrabuwa na phosphorus ya kafa tsarin "layin fatalwa", babu makawa zai rage kayan aikin injiniya na kayan. Rarrabuwar sinadarin phosphorus a cikin karfen da aka haɗa da carbon abu ne na kowa, amma digirinsa ya bambanta. Tsananin rabuwar phosphorus (tsarin "layin fatalwa") zai haifar da mummunan tasiri akan karfe. Babu shakka, tsananin rarrabuwar kawuna na phosphorus shine laifin fashewar sanyi. Saboda abun ciki na phosphorus a cikin nau'in hatsi daban-daban na karfe ya bambanta, kayan suna da ƙarfi da taurin daban-daban. A gefe guda, yana sa kayan ke haifar da damuwa na ciki, wanda zai sa kayan da sauƙi don fashewa. A cikin kayan da tsarin "fatalwa" tsarin, shi ne daidai saboda rage taurin, ƙarfi, elongation bayan karaya da raguwa na yanki, musamman ma rage tasiri taurin, cewa phosphorus abun ciki a cikin kayan yana da dangantaka mai girma tare da tsarin kuma. Properties na karfe.
A cikin "layin fatalwa" a tsakiyar filin hangen nesa, an gano adadi mai yawa na bakin ciki, sulfide mai launin toka mai haske ta hanyar metallography. Abubuwan da ba na ƙarfe ba a cikin ƙarfe na tsari galibi suna kasancewa a cikin nau'in oxides da sulfides. A cewar GB/T10561-2005 Madaidaicin Jadawalin Rabe-rabe don Abubuwan da ba na ƙarfe ba a cikin Karfe, abun ciki na sulfide na haɗa Class B shine 2.5 ko sama. Haɗin da ba na ƙarfe ba shine yuwuwar tushen fashewa. Kasancewarsa zai lalata ci gaba da ƙarancin tsarin karfe, don haka yana rage ƙarfin intergranular sosai.
Ana tsammanin cewa sulfide a cikin tsarin ciki "layin fatalwa" na karfe shine mafi sauƙin fashe. Saboda haka, babban adadin fasteners fashe a cikin sanyi heading da zafi magani quenching a samar wurin, wanda aka lalacewa ta hanyar babban adadin haske launin toka dogon sulfide. Wannan masana'anta mara saƙa ta lalata ci gaban kaddarorin ƙarfe kuma ya ƙara haɗarin maganin zafi. Ba za a iya cire "layin fatalwa" ta hanyar daidaitawa da sauran hanyoyin ba, kuma za a iya sarrafa abubuwa masu ƙazanta sosai kafin narkewa ko albarkatun ƙasa su shiga shuka. Dangane da abun da ke ciki da nakasa, an rarraba abubuwan da ba na ƙarfe ba zuwa alumina (nau'in A) silicate (nau'in C) da spherical oxide (nau'in D). Bayyanar sa zai yanke ci gaba da ƙarfe kuma ya zama rami ko tsagewa bayan kwasfa, wanda ke da sauƙin haifar da tsagewa yayin yanayin sanyi kuma yana haifar da damuwa yayin maganin zafi, don haka yana haifar da tsagewar. Don haka, abubuwan da ba na ƙarfe ba ya kamata a sarrafa su sosai. Tsarin Karfe Tsarin Carbon Tsarin Yanzu GB/T700-2006 da GB T699-2016 Babban Ingancin Carbon Karfe sun gabatar da buƙatu don abubuwan da ba na ƙarfe ba. Don mahimman sassa, gabaɗaya shine nau'in nau'in nau'in nau'in nau'in A, B, C, jerin masu kyau ba su wuce 1.5 ba, D, tsarin tsarin nau'in Ds da matakin 2 bai wuce matakin 2 ba.

Hebei Chengyi Engineering Materials Co., Ltd. kamfani ne mai shekaru 21 na samarwa da ƙwarewar tallace-tallace. Masu haɗe-haɗenmu suna amfani da albarkatun ƙasa masu inganci, haɓaka haɓakawa da fasahar kere kere, da ingantaccen tsarin gudanarwa don tabbatar da ingancin samfur. Idan kuna sha'awar siyan kayan ɗamara, da fatan za a tuntuɓe mu.