Lokacin da kuka ji '2Cr13 bakin karfe', tunanin nan da nan ga mutane da yawa shine kawai wani babban darajar martensitic, mai kyau ga wukake da bawuloli masu arha. Wannan ba kuskure ba ne, amma sauƙaƙawa ne wanda ke haifar da ƙarin ciwon kai na kanti fiye da yadda ya kamata. Gaskiyar ita ce, halinsa yana zaune a cikin wannan tsaka-tsakin tsaka-tsakin-ba a gafartawa kamar 304 ba, ko kuma mai ƙarfi kamar 440C. Samun daidaitaccen sakamako tare da shi, musamman a cikin simintin gyare-gyare da gyare-gyare, yana buƙatar ka mutunta ƙayyadaddun ƙayyadaddun sa.
Matsalolin Casting: Fluidity vs. Cracking
A cikin ƙirar harsashin mu da layukan simintin saka hannun jari, 2Cr13 shine mai saurin tashi don jikin famfo, injina, da wasu sassan injinan abinci. Nuance na farko shine zuba zafin jiki. Za ku yi tunani tare da matsakaicin carbon ɗin sa (~ 0.16-0.25%) da 13% Cr, kai tsaye. Amma iyakar ƙarfinsa ya fi kunkuntar fiye da yadda kuke tsammani. Zuba da sanyi sosai, kuma kuna samun misstruns, musamman a cikin sassan bakin ciki na ruwan wukake. Zuba zafi da yawa, da haɗarin ƙwanƙolin zafi mai zafi, musamman a kusa da kusurwoyin ciki masu kaifi na jikin bawul. Mun koya, ta hanyar fiye da ƴan simintin gyare-gyare, don yin nufin mafi girman ƙarshen kewayon da aka ba da shawarar amma tare da maƙarƙashiya mai ƙarfi. Yana nufin ba shi isasshen ruwa don cika ƙura ba tare da matsananciyar ƙarfin harsashi ba.
Sa'an nan akwai hulɗar kayan ƙira. Saboda yana da martensitic, yana canzawa kuma yana raguwa daban fiye da maki austenitic. Tare da simintin saka hannun jari ta amfani da harsashi yumbu, dole ne mu daidaita yanayin zafin harsashi kafin zafi. Daidaitaccen zafin zafi na 304 ya haifar da fashewa a cikin simintin gyare-gyare na 2Cr13 saboda girgizar zafi yayin zubarwa ya fi tsanani. Yanzu mun riga mun yi zafi kadan mafi girma, wanda alama ce ta rashin fahimta don rage damuwa, amma ya yi aiki. Ya rage saurin sanyaya na farko kawai isa ya bar fatar karfe ta zama iri ɗaya.
Maganin zafi bayan simintin gyare-gyare ba za a iya yin sulhu ba. As-cast 2Cr13 ba shi da ƙarfi. Dole ne ku shafe shi. Madaidaicin yarjejeniya yana dumama zuwa kusan 850-900C, riƙewa, da sanyaya tanderu. Amma ga fa'ida mai amfani: yawan sanyaya a cikin tanderu yana da mahimmanci. Mun taɓa samun ɗigon simintin gyare-gyaren simintin gyare-gyare waɗanda suka wuce gwaje-gwajen taurin amma ba su yi aiki da kyau ba, suna nuna wuce gona da iri. Batun ya samo asali ne daga tanderun da aka yi lodi da yawa inda sassa a tsakiya suka yi sanyi a hankali, kusan kamar anneal na subcritical, yana barin ƙananan tsarin ƙasa da manufa. Yanzu mun tabbatar da mafi kyawun tazarar lodi. Waɗannan ƙananan karkatattun tsarin ne suke cizon ku.
Machinability: Gaskiyar Gummy
A kan takarda, ƙimar aikin injin sa ba laifi. A kan bene na CNC, masu aiki za su gaya muku yana iya zama ɗanɗano ko kirtani, musamman a yanayin da ba a taɓa gani ba. Ba ya karya kwakwalwan kwamfuta da tsabta kamar karfe 12L14, kuma ba shi da tsaftataccen yanke kamar 303 bakin karfe. Makullin shine sarrafa ƙarfin aiki. Idan adadin abincin ku ya yi ƙasa da ƙasa ko kayan aiki ya zauna, nan da nan za ku yi aiki-taurara saman, kuma wucewa ta gaba ta yi hira ko ƙone kayan aikin. Mun ƙididdige kayan aikin carbide tare da kaifi, goge fuskar rake kuma muna amfani da ƙimar abinci mafi girma tare da matsakaicin gudu. Coolant yana da mahimmanci, ba kawai don sanyaya ba amma don taimakawa wajen wanke waɗancan guntu masu ƙarfi.
Haƙa ramuka masu zurfi ƙalubale ne na musamman. Madaidaicin maki 118-digiri na iya yawo kuma ya haifar da zafi mai yawa. Mun canza zuwa 135-digiri tsaga-point drills tare da a hankali pecking sake zagayowar da kuma ƙara coolant matsa lamba. Ya kara lokacin sake zagayowar amma ya kawar da yawancin sake aiki da kayan aikin da suka karye. Don kamfani kamar Qingdao Qiangsenyuan Technology Co., Ltd. (QSY), wanda ke sarrafa komai daga jefawa zuwa na ƙarshe Injin CNC ƙarƙashin rufin ɗaya, waɗannan haɗin gwiwar ilmantarwa suna da mahimmanci. Ba za ku iya inganta injina a keɓe ba; dole ne ku yi lissafin yanayin simintin simintin gyare-gyare da tarihin maganin zafi na blank. Wani bangare da aka goge dan kadan daga-spec zai yakar ku a kan lathe duk rana.
Na tuna wani aiki don jerin spools na hydraulic bawul. Buga ya yi kira da a yi kyakkyawan gamawa a kan filaye. Juya 2Cr13 zuwa wannan ƙare yana da matsala - mun ci gaba da samun tsagewar, abin shafa. We experimented with different insert geometries and finally found that a wiper-style insert with a very light final finishing pass, using a specific high-lubricity cutting fluid (not our standard coolant), did the trick. Ba a cikin daidaitaccen littafin injuna; Gyaran falon kanti ne ya haifar da takaici.
Juriya na Lalacewa: Tsara Tsammani masu Dama
Wannan shine inda kuskuren abokin ciniki ya fi girma. Mutane suna ganin bakin karfe kuma suna ɗaukan tsatsa ce. 2Cr13 bakin karfe yana bada matsakaicin juriya na lalata kawai. Yana da kyau ga wurare masu laushi masu laushi, kamar wasu acid abinci ko bayyanar yanayi, amma zai shiga cikin saitunan chloride (ruwa mai gishiri, gishiri mai nauyi). Kullum muna wannan tattaunawa tare da abokan ciniki. Don bangaren marine, za mu tura 316L. Amma ga, ka ce, ɓangaren injin biredi da aka fallasa ga kullu acids da tururi, 2Cr13 yana da tsada-tasiri kuma daidai ne.
Passivation yana taimakawa, amma ba maganin mu'ujiza bane. Tsarin maki na martensitic kamar wannan ya bambanta da baho na nitric acid da ake amfani da su don austenitics. Muna amfani da tsarin wucewa na tushen citric acid, wanda yake da tasiri kuma ya fi dacewa da muhalli. Duk da haka, nasararsa gaba ɗaya ya dogara ne akan saman kasancewarsa cikakke mai tsabta kafin wanka. Duk wani baƙin ƙarfe da aka haɗa daga mashina ko sarrafawa zai lalata layin da ba a so. Mun aiwatar da tsauraran matakan tsaftacewa da dubawa kafin wucewa, wanda hakan ya rage koke-koke-tsatsawar tabo akan sassan da aka gama.
Yanayin maganin zafi yana rinjayar aikin lalata kai tsaye. Bangaren da ya dace da kyau zai sami juriya mafi kyau fiye da wanda kawai ake kawar da damuwa. Mun tattara wannan ta hanyar gwada samfurori daga batches daban-daban a cikin majalisar feshin gishiri. Bayanan sun taimaka mana tabbatar da cikakkiyar ka'idar kula da zafi ga abokan cinikin da ke ƙoƙarin ƙimanin injiniyan da ya fita. Tsallake maganin zafi mai kyau don adana farashi yawanci yana komawa baya tare da gazawar cikin sabis.
Welding da Kera: Ci gaba da taka tsantsan
Yana da walƙiya, amma ba abokantaka ba ne. Ana ba da shawarar zafin zafin jiki mai ƙarfi, a kusa da 200-300 ° C, kuma jiyya mai zafi bayan walda (PWHT) kusan koyaushe ya zama dole don dawo da ductility da juriya na lalata a cikin yankin da zafi ya shafa (HAZ). Idan ka tsallake PWHT, HAZ ya zama mai wuya, gaggautsa, kuma mai saurin fashewa. Mun koyi wannan da wuri a kan gyara tsagewar simintin gyaran kafa. Weld ɗin gyara ba tare da zafin zafin jiki ba da PWHT sau da yawa zai sake fashe nisan ƴan milimita daga ƙullin walda.
Don ƙirƙira kayan waldawa daga faranti ko mashaya, zaɓin ƙarfe mai filler yana da mahimmanci. Zaɓuɓɓukan gama gari sune 309L ko 312 bakin lantarki, waɗanda ke da babban abun ciki na gami don rama dilution da hana taurin wuce kima. Ko da a lokacin, sarrafa zafin tsaka-tsaki shine maɓalli. Muna kula da shi kamar walda ƙaramin ƙarfe fiye da bakin karfe. Canjin tunani yana da mahimmanci.
Yunkurin da bai yi nasara ba ya haɗa da abokin ciniki wanda ke son taron welded na faranti 2Cr13 da kayan aikin simintin gyare-gyare. Sun dage kan babu PWHT saboda matsalolin kwanciyar hankali. Mun yi gargadi a kan hakan amma mun ci gaba da bukatarsu. Sassan sun wuce binciken farko amma sun fashe a cikin hanyar wucewa yayin lokacin sanyi. Ragowar damuwa daga walda, haɗe tare da ƙarancin zafin jiki na martensite mara ƙarfi a cikin HAZ, ya haifar da shi. Yanzu muna buƙatar rattaba hannu idan abokin ciniki ya ƙi shawarar PWHT. Bai cancanci lalacewar mutunci ba.
Samfura da daidaiton Abu: Maɓallin Boye
Ba duk 2Cr13 aka halicce su daidai ba. Bambance-bambancen abubuwan da aka gano kamar su sulfur, phosphorus, da silicon tsakanin injina daban-daban na iya yin tasiri sosai ga iyawa da injina. Mun daidaita sarkar samar da kayayyaki gwargwadon yiwuwa kuma mun nemi rahoton gwajin niƙa don ayyuka masu mahimmanci. Batch tare da sulfur a babban ƙarshen ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun bayanai na iya yin na'ura da ɗan kyau amma zai iya zama mai saurin tsagewa yayin yin simintin gyare-gyare.
Yin aiki tare da abokin tarayya na dogon lokaci kamar QSY, tare da shekarun da suka gabata zuba jari da machining, yana nuna darajar wannan iko. Za mu iya gano batun mashin ɗin zuwa wani takamaiman zafin ƙarfe kuma mu daidaita sigoginmu na sama daidai. Misali, idan sabon tsari ya fi jin zafi a tuntuɓar kayan aiki na farko, za mu bincika ainihin abun cikin carbon akan cert kuma za mu iya daidaita yanayin zafi da ƙima kafin ma mu fara cikakken samarwa. Wannan hanya mai fa'ida tana adana ton na raguwar lokaci.
A ƙarshe, yana da game da sanin lokacin da ba za a yi amfani da shi ba. Tare da tashi na musamman gami kamar super duplex ko tushen nickel don matsananciyar mahalli, aikin 2Cr13 shine abin dogaro, zaɓi na tattalin arziki don takamaiman aikace-aikacen da aka fahimta sosai. Dokin aiki ne, ba dokin show ba. Ƙimar sa ta ta'allaka ne a cikin aikin da ake iya faɗi a cikin iyakokinta, kuma ainihin ƙwarewar ita ce a cikin ma'anar da mutunta iyakokin ta kowane mataki-daga tanderun da aka samo asali zuwa gwajin QC na ƙarshe. Wannan shine inda shekaru 30 na gwaninta a kamfani kamar namu ya faɗa da gaske.
