Wava nechokwadi chekuti zvikamu zvacho zvakagadzirwa nemachina zvichienderana nezvaunoda. Iye zvino, iva nechokwadi chekuti watora matanho ekudzivirira zvikamu izvi mumamiriro ezvinhu anotarisirwa nevatengi vako.#basic
Kunyudza kunoramba kuri danho rakakosha mukuwedzera kusimba kwesimbi muchina wesimbi usingapindi ngura. Kunogona kuita mutsauko pakati pekushanda zvakanaka nekutadza kushanda zvakanaka. Kunyudza kusingapindi ngura kunogona kukonzera ngura kana zvinhu zvikasashanda zvakanaka.
Kuisa pasi inzira inoshandiswa mushure mekugadzira iyo inowedzera kuramba kwengura kwesimbi dzisina ngura dzinogadzira workpiece. Haisi nzira yekubvisa ngura, uye haisi pendi.
Hapana kubvumirana kwakawanda pamusoro pekuti mashandiro chaiwo epassivation anoshanda sei. Asi zvine chokwadi kuti pane firimu rekuchengetedza oxide pamusoro pesimbi isina tsvina isina kupiswa. Iyi firimu isingaoneki inofungidzirwa kuti yakatetepa zvikuru, iri pasi pe 0.0000000 inch ukobvu, inenge 1/100,000th ukobvu hwebvudzi remunhu!
Chikamu chesimbi isina tsvina chakachena, chitsva chakagadziriswa, chakakweshwa kana chakabikwa munyu chinozowana firimu re oxide iyi otomatiki nekuda kwekusangana kwayo ne oxygen yemumhepo. Mumamiriro ezvinhu akanaka, jira iri re oxide rinodzivirira rinofukidza zvachose nzvimbo dzese dzechikamu chacho.
Zvisinei, mukuita, tsvina yakaita sevhu remuchitoro kana zvidimbu zvesimbi zvinobva muzvishandiso zvekucheka zvinogona kutamiswa pamusoro pezvikamu zvesimbi isingatsvi panguva yekugadzirwa. Kana zvikasabviswa, zvinhu izvi zvekunze zvinogona kuderedza kushanda kwefirimu rekudzivirira rekutanga.
Panguva yekugadzirwa, huwandu hwesimbi hunogona kupwanya chishandiso ichi uye hunoenda pamusoro pechinhu chesimbi chisina ngura. Mune zvimwe zviitiko, ngura yakatetepa inogona kuoneka pachikamu chacho. Uku ndiko ngura yesimbi nechinhu chacho, kwete yesimbi yekutanga. Dzimwe nguva, zvidimbu zvesimbi zvakaputirwa kubva kumidziyo yekucheka kana zvigadzirwa zvavo zvengura zvinogona kukonzera kukuvara kwechikamu chacho pachacho.
Saizvozvowo, zvidimbu zvidiki zvevhu resimbi zvinogona kunamira pamusoro pechinhu chacho. Kunyangwe simbi ingaita seinopenya kana yagadzirwa nemashini, mushure mekusangana nemhepo, zvidimbu zvisingaoneki zvesimbi yakasununguka zvinogona kukonzera ngura pamusoro.
Masulfide akafumurwa anogonawo kuva dambudziko. Anobva pakuwedzera sarufa kusimbi isingatsvedzeri kuti michina ishande zvakanaka. Masulfide anowedzera kugona kwesimbi kugadzira machipisi panguva yekugadzirwa, ayo anogona kubviswa zvachose kubva pamudziyo wekucheka. Kana zvikamu zvisina kupfava zvakanaka, masulfide anogona kuva pokutangira ngura pamusoro pezvinhu zvakagadzirwa.
Muzviitiko zvese izvi, kunyungudutsa kunodiwa kuti simbi isingatsvinyike irambe yakasimba. Inobvisa tsvina pamusoro, senge ferrous shop ivhu uye simbi muzvishandiso zvekucheka, izvo zvinogona kugadzira ngura kana kuva pokutangira kunyungudutsa. Kunyungudutsa kunobvisawo sulfide dzakaratidzwa pamusoro pesimbi isingatsvinyike dzakachekwa.
Maitiro ane matanho maviri anopa simba rakanakisisa rekudzivirira ngura: 1. Kuchenesa, nzira iri nyore asi dzimwe nguva isingatariswe; 2. Kugeza neasidhi kana kurapwa kwepasi.
Kuchenesa kunofanira kugara kuri chinhu chinonyanya kukosheswa. Nzvimbo dzinofanira kucheneswa zvakakwana kubva mumafuta, chinotonhodza kana mamwe marara emuchitoro kuti dzisaparare ngura zvakanyanya. Marara emuchina kana mamwe tsvina yemuchitoro anogona kubviswa nokungwarira kubva muchikamu chacho. Zvinobvisa mafuta kana zvinochenesa zvekutengesa zvinogona kushandiswa kubvisa mafuta ekugadzira kana zvinotonhodza. Zvinhu zvekunze zvakaita se thermal oxides zvinogona kubviswa nenzira dzakadai sekukuya kana kusvina.
Dzimwe nguva mushandisi wemuchina anogona kusvetuka kuchenesa zvinhu zvishoma, achifunga zvisirizvo kuti kuchenesa nekurega kushandisa mafuta zvichaitika panguva imwe chete nekungonyika chikamu chine mafuta mubhavhu rine acid. Izvi hazvizoitiki. Kusiyana neizvi, mafuta ane tsvina anosangana neacid kuti agadzire mabubble emhepo. Mabubble aya anoungana pamusoro pebasa uye anopindira nekurega kushandisa mafuta.
Zvinotonyanya kuipa ndezvekuti, kusvibiswa kwemvura inonyungudutsa, dzimwe nguva ine huwandu hwakawanda hwema chloride, kunogona kukonzera "kupenya." Kusiyana nekuwana firimu re oxide rinodiwa rine nzvimbo inopenya, yakachena, inodzivirira ngura, kupenya kwechiedza kunogona kukonzera kuora kwenzvimbo kana kuti rima—kukanganisa kwenzvimbo uko kupenya kwakagadzirirwa kuti kuwedzere kunaka.
Zvikamu zvakagadzirwa nesimbi isina tsvina yemartensitic [ine magineti, inodzivirira ngura zvine mwero, inosimba kusvika pa280 ksi (1930 MPa)] zvinoomeswa pakupisa kwakakwira uye zvinozonyoroveswa kuitira kuti pave nekuomarara kwaunoda uye hunhu hwemakanika. Ma alloys anoomarara ekunaya kwemvura, ane simba riri nani uye anodzivirira ngura kupfuura ma alloys emartensitic, anogona kugadziriswa, kugadzirwa muchina zvishoma, kucheneswa pakupisa kwakaderera, uye opedzwa.
Muchiitiko ichi, chikamu chinofanira kucheneswa zvakanaka ne degreaser kana cleaner kubvisa chero zvisaririra zve kucheka mvura isati yashandiswa kupisa. Zvikasadaro, kucheka mvura inosara pachikamu ichi kunogona kukonzera oxidation yakawandisa. Izvi zvinogona kukonzera kuti zvikamu zvisina kukura zviboore mushure mekunge ganda rabviswa nenzira ye acid kana abrasive. Kana kucheka mvura ikabvumirwa kuramba iri pazvikamu zvakaomeswa, zvakaita semu vacuum fire kana mumhepo inodzivirira, carburization yepamusoro inogona kuitika, zvichikonzera kurasikirwa ne corrosion resistance.
Mushure mekucheneswa kwakanyatsonaka, zvikamu zvesimbi isina ngura zvinogona kunyudzwa mubhavhu rinopisa acid. Chero nzira nhatu dzinogona kushandiswa - nitric acid passivation, nitric acid ine sodium dichromate passivation, uye citric acid passivation. Nzira yekushandisa inoenderana negiredhi resimbi isina ngura uye zvinodiwa zvakatarwa.
Magiredhi akawanda echrome-nickel anodzivirira ngura anogona kupfava mubhavhu re 20% (v/v) nitric acid (Mufananidzo 1). Sezvinoratidzwa mutafura, simbi isingapfava inogona kupfava nekuwedzera sodium dichromate mubhavhu re nitric acid, zvichiita kuti mhinduro ive inonyungudutsa uye ikwanise kugadzira firimu risingapfava pamusoro pesimbi. Imwe nzira yekutsiva nitric acid ne sodium chromate ndeyekuwedzera huwandu hwe nitric acid kusvika 50% nehuwandu. Kuwedzerwa kwe sodium dichromate uye huwandu hwakawanda hwe nitric acid zvinoderedza mukana we flash isingadiwe.
Maitiro ekushandisa simbi dzisina kugadzirwa dzinoshandisa machining (anoratidzwawo muMufananidzo 1) akasiyana zvishoma neaya emhando dzesimbi dzisina kugadzirwa dzinoshandisa machining. Izvi zvinodaro nekuti panguva yekushandiswa mubhavhu re nitric acid, mamwe kana ese ma sulfide ane machining anobviswa, zvichiita kuti pave nekusagadzikana kudiki pamusoro pechikamu chakashandiswa machining.
Kunyangwe kusukurudza nemvura kunoshanda kunogona kusiya asidhi yasara muzvirambidzo izvi mushure mekupfava. Asidhi iyi inozorwisa pamusoro pechikamu kunze kwekunge isina kunyungudutswa kana kubviswa.
Kuti simbi isingatsvedzeri inogadziriswa nyore nyore, Carpenter akagadzira nzira yeAAA (Alkali-Acid-Alkali), iyo inobvisa acid yakasara. Nzira iyi yekubvisa acid inogona kupedzwa mumaawa asingasviki maviri. Heino nzira yekutevera nhanho nhanho:
Mushure mekudzima mafuta, nyika zvikamu zvacho mu 5% sodium hydroxide solution pa 160°F kusvika 180°F (71°C kusvika 82°C) kwemaminitsi makumi matatu. Wobva wasuka zvikamu zvacho zvakanaka mumvura. Zvadaro, nyika chikamu chacho kwemaminitsi makumi matatu mumushonga we 20% (v/v) nitric acid une 3 oz/gal (22 g/l) sodium dichromate pa 120°F kusvika 140°F (49°C) kusvika 60°C). Mushure mekubvisa chikamu mubhavhu, chisuke nemvura wozochinyika mumushonga we sodium hydroxide kwemamwe maminitsi makumi matatu. Sukurudza chikamu chacho zvakare nemvura wochiomesa, uchipedzisa nzira yeAAA.
Kushandiswa kweCitric acid passivation kuri kuwedzera kufarirwa nevagadziri vanoda kudzivisa kushandisa mineral acids kana mhinduro dzine sodium dichromate, pamwe nematambudziko ekurasa zvinhu uye kuchengetedzeka kukuru kunokonzerwa nekushandiswa kwazvo. Citric acid inoonekwa seyakachengeteka nharaunda munzira dzese.
Kunyange zvazvo kunyungudutsa kwe citric acid kuchipa zvakanakira zvakatipoteredza zvinoyevedza, zvitoro zvakabudirira nekunyungudutsa kwe inorganic acid uye zvisina hanya nekuchengetedzwa kwezvakatipoteredza zvingada kuramba zviri mugwara iri. Kana vashandisi ava vaine chitoro chakachena, michina yakachengetedzwa zvakanaka uye yakachena, chinhu chinotonhodza chisina tsvina yesimbi, uye maitiro anounza mhedzisiro yakanaka, pangave pasina chikonzero chaicho chekuchinja.
Kunyudza mubhavhu re citric acid kwakawanikwa kuchishanda kune mhando dzakasiyana dzesimbi dzisina ngura, kusanganisira mhando dzakasiyana dzesimbi dzisina ngura, sezvakaratidzwa muMufananidzo 2. Kuti zvive nyore, nzira yechinyakare yekubvisa nitric acid muMufananidzo 1 inosanganisirwa. Cherechedza kuti maformula ekare e nitric acid anoratidzwa muhuwandu hwezana, nepo huwandu hutsva hwe citric acid hunoratidzwa muhuremu hwezana. Zvakakosha kuziva kuti pakushandisa maitiro aya, kuyera nguva yekunyorova, tembiricha yekugeza uye huwandu hwayo kwakakosha kudzivirira "kupenya" kwakatsanangurwa kare.
Kurapa kwepassivation kunosiyana zvichienderana nehuwandu hwechromium uye hunhu hwemachining hwegiredhi rega rega. Cherechedza makoramu anotsanangura Maitiro 1 kana Maitiro 2. Sezvakaratidzwa muMufananidzo 3, Maitiro 1 anosanganisira matanho mashoma pane Maitiro 2.
Kuongororwa kwemurabhoritari kwakaratidza kuti maitiro ekubvisa citric acid anowanzo "penya" kupfuura maitiro e nitric acid. Zvinhu zvinokonzera kurwiswa uku zvinosanganisira kupisa kwakanyanya kwekugezera, nguva yakareba yekunyikwa, uye kusvibiswa kwebhavhu. Zvigadzirwa zveCitric acid zvine zvinodzivirira ngura nezvimwe zvinowedzera zvakaita sezvinwiwa zvinonyorovesa zvinowanikwa kutengeswa uye zvinonzi zvinoderedza mukana we "flash corrosion".
Sarudzo yekupedzisira yenzira yekusashandisa Indaneti inoenderana nezvinodiwa nemutengi. Ona ASTM A967 kuti uwane rumwe ruzivo. Inogona kuwanikwa pa www.astm.org.
Miedzo inowanzoitwa kuti iongorore pamusoro pezvikamu zvisina simba. Mubvunzo wekupindura ndewokuti, "Kukwanisa kudzima simbi kunobvisa simbi isina simba here uye kunogadzirisa kuramba ngura kwemhando dzekucheka pasina simba here?"
Zvakakosha kuti nzira yekuyedza ienderane negiredhi riri kuongororwa. Miedzo yakanyanya kuomarara ichakundikana zvinhu zvakanaka, nepo bvunzo dzakasununguka dzichipasa zvikamu zvisingagutsi.
Kuomesa mvura nesimbi dzisina ngura dzinoshandiswa muchina we400 series uye simbi dzisina ngura dzinoshandiswa muchina we freemachine zvinoongororwa zvakanaka mukabati inokwanisa kuchengetedza hunyoro hwe100% (sample wet) kwemaawa makumi maviri nemana pa95°F (35°C). Chikamu chemuchinjiko chinowanzova nzvimbo inonyanya kukosha, kunyanya kune ma free-cutting grades. Chimwe chikonzero cheizvi ndechekuti sulfide yakarebeswa muchina, ichibatana nepamusoro apa.
Nzvimbo dzakakosha dzinofanira kuiswa mudenga, asi pa15 kusvika 20 degrees kubva kumusoro kuti hunyoro husapere. Zvinhu zvisina kunyorova zvakanaka hazvizomboiti ngura, kunyangwe zvingaratidza ruvara rudiki.
Magiredhi esimbi isina tsvina yeAustenitic anogonawo kuongororwa nekuongororwa kwehunyoro. Kana zvaitwa, madonhwe emvura anofanira kunge aripo pamusoro pemuenzaniso, zvichiratidza kuti simbi haina ngura.
Maitiro ekubvisa simbi dzisina kuchena dzinoshandiswa zvakanyanya uye dzisingacheki zvisina kuchena mumhinduro dze citric kana nitric acid anoda maitiro akasiyana. Mufananidzo 3 uri pazasi unopa ruzivo rwekusarudza maitiro.
(a) Gadzirisa pH ne sodium hydroxide.(b) Ona Mufananidzo 3 (c) Na2Cr2O7 inomiririra 3 oz/gallon (22 g/l) sodium dichromate mu 20% nitric acid. Imwe nzira yekubatanidza iyi i 50% nitric acid isina sodium dichromate.
Nzira inokurumidza ndeyekushandisa mhinduro iri muASTM A380, "Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems." Kuedza uku kunosanganisira kupukuta chikamu chacho ne copper sulfate/sulfuric acid solution, kuchichengetedza chakanyorova kwemaminitsi matanhatu uye kutarisa copper plating. Imwe nzira, chikamu chacho chinogona kunyudzwa mumvura kwemaminitsi matanhatu. Kana iron ikanyunguduka, copper plating inoitika. Kuedza uku hakushande pamusoro pezvikamu zvekugadzira chikafu. Zvakare, hakufanirwe kushandiswa kune 400 series martensitic kana low chromium ferritic steels sezvo mhedzisiro yenhema inogona kuitika.
Kare, bvunzo ye5% yemunyu inopfapfaidzwa pa95°F (35°C) yakashandiswawo kuongorora sampuli dzisina kunyudzwa. Bvunzo iyi yakanyanya kuomarara kune mamwe magiredhi uye kazhinji haidiwi kusimbisa kuti kunyudzwa kunoshanda.
Dzivisa kushandisa machloride akawandisa, ayo anogona kukonzera kurwiswa kwemhepo kunokuvadza. Kana zvichibvira, shandisa mvura yepamusoro chete ine zvikamu zvisingasviki makumi mashanu pamamiriyoni (ppm) chloride. Mvura yepombi inowanzo kukwana uye inogona kushivirira kusvika mazana akati wandei eppm chloride mune dzimwe nguva.
Zvakakosha kutsiva imba yekugezera nguva nenguva kuitira kuti isarasikirwa nekukwanisa kunyura, izvo zvinogona kukonzera mheni uye kukuvara kwezvikamu. Imba yekugezera inofanira kuchengetedzwa patembiricha yakakodzera, sezvo tembiricha dzinobva panzvimbo imwe chete dzinogona kukonzera ngura.
Zvakakosha kuchengetedza purogiramu chaiyo yekuchinja mhinduro panguva yekugadzirwa kwakanyanya kuderedza mukana wekusvibiswa. Muenzaniso wekuongorora wakashandiswa kuyedza kushanda kwebhavhu. Kana muenzaniso ukarwiswa, inguva yekutsiva bhavhu.
Ndapota taurai kuti mimwe michina inogadzira simbi isingatsvi chete; shandisai chinhu chimwe chete chinotonhodza simbi iyi, musingabatanidzi dzimwe simbi dzese.
Zvikamu zveraki zveDO zvinogadziriswa zvakasiyana kudzivirira kusangana kwesimbi nesimbi. Izvi zvakakosha zvikuru pakugadzira simbi isingatsvedzeri, sezvo mhinduro dzinoyerera dzichiyerera uye dzinosuka dzichidiwa kuti dziparadzire zvigadzirwa zve sulfide ngura uye kudzivirira kuumbwa kwe acid pockets.
Usashandise zvikamu zvesimbi isina ngura zvakakangwa kana kuti zvakacheneswa ne nitride. Kusagona ngura kwezvikamu zvakacheneswa kunogona kudzikira kusvika pazvinogona kurwiswa mubhavhu rekushambira.
Usashandise maturusi esimbi munzvimbo isina kuchena zvakanyanya muworkshop. Matombo esimbi anogona kudzivirirwa nekushandisa maturusi ecarbide kana ceramic.
Musakanganwa kuti ngura inogona kuitika mubhavhu repasi kana chikamu chacho chisina kurapwa zvakanaka. Kabhoni yakawanda, ine chromium yakawanda, inofanira kuomeswa kuti isapararire ngura.
Kudzikisa kunowanzoitwa mushure mekudzikisa kunotevera uchishandisa tembiricha dzinochengetedza kuramba kwengura.
Usaregeredza huwandu hwe nitric acid mubhavhu repasi. Kuongorora kunofanira kuitwa nguva nenguva uchishandisa nzira iri nyore yetitration inopihwa naCarpenter. Usapfuure simbi dzinopfuura imwe chete panguva imwe chete. Izvi zvinodzivirira kuvhiringidzika kunodhura uye zvinodzivirira galvanic reactions.
Nezvevanyori: Terry A. DeBold inyanzvi yekutsvagisa nekugadzira alloy yesimbi isingasvibi uye James W. Martin inyanzvi yesimbi dzemabhawa kuCarpenter Technology Corp. (Reading, PA).
Munyika ine mitemo yakaoma yekupedzisa pamusoro, zviyero zviri nyore zve "roughness" zvichiri kubatsira. Ngationei kuti nei kuyerwa kwepamusoro kuchikosha uye kuti kunogona sei kuongororwa pasi pechitoro uchishandisa magauge epamusoro anotakurika.
Une chokwadi here kuti une chinhu chakakodzera kupinza jira pakuita izvi? Tarisa chip, kunyanya kana chisina kutarisirwa. Hunhu hwechip hunogona kukuudza zvakawanda.