Mechanical Properties yeMetal Castings

In metal foundry, kiyi yekusimbisa iyokunaka kwe castingsIri mukusimudzira ruzivo rwemhando yevashandi vese vari mukati mebhizinesi, kusimbisa kutariswa kwemhando uye manejimendi pamusoro pese kugadzirwa kwemaitiro ekukanda, kudzikamisa maitiro ekugadzira, kuronga kugadzirwa kwakabudirira, uye kutora epamberi tekinoroji yekugadzira nemidziyo zvakanyanya sezvinobvira, zvakashongedzerwa zvakakwana. nzira dzekuongorora dzinoshanda dzemaitiro emhando uye kunaka kwekukanda.

Yakajairwa mechini kuita yekuyedza Iyo yakajairwa mechanic performance yekuyedza inoitwa pakamuri tembiricha. Zvinhu zvekuyedza zvinowanzo sanganisira kusimba kwesimba, kusimba kwegoho, kurebesa mushure mekutsemuka, kudzikiswa kwenzvimbo, kutsauka, kunyura (kana kukanganisa kuoma) uye kuoma. Kusimba kwesimba, kusimba kwegoho, kurebesa mushure mekutsemuka, uye kudzikiswa kwenzvimbo kunoyerwa pamushini wekuyedza tenesi; kunyura kana kukanganisa kusimba kunoyerwa pamushini wekuyedza kukanganisa; kutsveyamisa uye kukotama simba kunoyerwa nemachinjika ekukotama nzira dzekuyedza; kuomarara kunopimwa ne hardness tester.

 

 

1. Kusimba Simba

Iwo akatemerwa emhando dzesimbi yakakandwa anogadzirwa necylindrical single cast bvunzo mabara kana akasungirirwa bvunzo mabhawa. Iyo dhayamita yeimwe yekukanda test bar ndeye 30 mm, uye inodururwa mubatch imwechete sekukanda mune yakatwasuka yekukanda yakaoma jecha mold. Iyo dhayamita yechikamu chakafanana ndeye 20 mm ± 0.5 mm. Kana simba rekukotama uye kutsauka kuchishandiswa semamiriro ekugamuchirwa emidziyo yekukanda, bvunzo yekukotama inogona kuitwa, uye sampu yekukotama inotora zvakananga as-cast blank test bar ine dhayamita ye30 mm ± 1mm. Chimiro, saizi uye hunhu hwepamusoro hwematemu ebvunzo ekuenzanisa, kubhenda bvunzo sampuli uye se-akakanda blank mabhawa ebvunzo, tensile bvunzo uye kubhenda nzira dzekuyedza, tekinoroji zvinodiwa pamushini wekuyedza, uye kuverenga uye kugadzirisa zviyero zvekuyerwa zvese zvinoenderana nezviyero zveindasitiri. .

Tensile bvunzo nzira dzedzimwe simbi dzakakandwa uye alloys (kusanganisira saizi kuyerwa kweakasimba emhando, nzira dzekunamatira, chiyero chekuyedza, maitiro ekuyera maitiro, uye bvunzo mhinduro kutenderedza uye kugadzirisa, nezvimwewo), uye mhando uye muchinjiko-zvikamu zvematemu emhando uye chimiro. , geji kureba, saizi, uye mhando yepamusoro inofanirwa kusangana nezvinodiwa zve CBT228-200 "Metallic Material Tensile Test Method paKamuri. Tembiricha". Sample haibvumidzwe kuve nekukuvadzwa kwemuchina, kutsemuka, akakosha akachinjika mapanga mavanga, deformation iri pachena uye humwe hurema hunooneka. Ijecha rinonamira, zvimbi, maburrs uye zvimwe zvirema zvine nyama uye zvinonamatira pamusoro pesample zvinofanira kubviswa. Tensile mienzaniso inogona kutemwa kubva kune imwechete cast test block, yakasungirirwa cast test block kana muviri wekukanda. Mhando, chimiro uye saizi yeimwe yekukanda bvunzo block uye yakanamatira yekukanda bvunzo block, iyo yakachekwa chinzvimbo uye kutungamira kweine tensile specimen, nzira yekubatanidza uye nzvimbo yekubatanidza yeyakasungirirwa yekukanda test block uye muviri wekukanda, ichasarudzwa kana kubvumirana nemutengesi. uye mutengi maererano nechiyereso chinoenderana . Kana iyo yekukanda ichida kurapwa kwekupisa, iyo imwechete yekukanda test block inofanirwa kupisa kupisa muchoto chakafanana nekukanda, uye yakasungirirwa test block inofanira kudimburwa mushure mekupisa kupisa. Tensile mienzaniso yebrittle uye yakaoma zvinhu senge chena cast iron inogona kunge-yakakandwa cylindrical specimens, kana tensile sampuli dzakanyudzwa uye dzakagadziriswa nemachining uye kupisa kunobatwa muchoto chimwe chete nekukandwa. Sample chimiro, saizi, tekinoroji zvinodiwa uye kupisa kurapwa kunofanirwa kutaurirana nemapato ese.

 

2. Impact Simba

Iyo yekukanganisa bvunzo inoshandiswa kuona iko kukanganisa kunyura simba kana sampu yemhedzisiro yaputswa pasi pechipiri mhedzisiro mutoro. Muchina wekuyedza maitiro unofanirwa kusangana nezvinodiwa zveGB/T 3808-2002 "Kuongorora kwePendulum Impact Testing Machines" uye inofanirwa kuongororwa nguva nenguva nedhipatimendi renyika remetrology. Impact samples dzakakamurwa kuita V-notch impact samples, U-notch impact samples uye non-notch impact samples. Grey cast iron inotora isina kucherechedzwa cylindrical impact samples, iyo inogadzirwa kubva as-cast blank test bars ine dhayamita ye30 mm. Nhamba yezita ndeye 420 mm × 120 mm. Iyo yekukanda nzira yeyakavhurika bvunzo bhaa, tekinoroji inodiwa yemhedzisiro yemuenzaniso, tekinoroji paramita yemuchina wekuyedza, mamiriro ebvunzo uye nzira dzinofanirwa kusangana nezvinodiwa zveGB 6296-1986 "Impact Test Method yeGrey Cast Iron". Impact samples dzebrittle and hard materials senge white cast iron can be unnotched as-cast blank samples, kana sampuli dzisina kucherechedzwa dzakanyudzwa uye dzakagadziriswa nemachining uye kupisa kunobatwa muchoto chimwe chete nekukandwa. Chimiro, saizi uye tekinoroji zvinodiwa zvemuenzaniso zvinotemwa nekupa uye kudiwa. Dzimwe simbi dzakakandwa uye alloys ndeye U-yakaita semhedzisiro yemuenzaniso (inowanzo shandiswa simbi dzakakandwa uye alloys ane hombe notch senitivity) kana V-yakaita semhedzisiro yemuenzaniso inoshandiswa semuenzaniso wekurova.

U-shaped kana V-shaped impact samples inogona kutorwa kubva kune single-cast test blocks (tsvimbo), akabatanidzwa-akakanda bvunzo mabhuroko (tsvimbo) kana miviri yekukanda. Iyo sampling nzvimbo uye kutungamira, mhando, chimiro, saizi uye nzira yekukanda yeimwe yekukanda bvunzo block (tsvimbo) uye yakanamatira casting test block (tsvimbo), uye nzira yekubatanidza uye yekubatanidza nzvimbo yeyakasungirirwa yekukanda test block (tsvimbo) uye yekukanda. mutumbi uchave wakavakirwa pamapato ekupa uye kudiwa Iwo anowirirana ekukanda zviyero anosarudzwa kana kubvumirana. Pakukanda kunoda kurapwa kwekupisa, iyo yakasungirirwa test block ichagurwa mushure mekupisa kupisa, uye iyo imwechete cast test block (bar) ichave inobatwa kupisa muchoto chakafanana nekukanda. Saizi yezita reV-yakaita uye U-yakaita notch inokanganisa yakajairwa mienzaniso ndeye 10mm×10mm×50mm, uye yakadzika notch kudzika: V-yakaita notch kudzika i2mm; U-shaped notch kudzika i2mm uye 5mm. Iyo dimensional kushivirira, hutsinye hwepamusoro uye humwe hunyanzvi mamiriro eiyo noted impact test samples, mamiriro, nzira uye kurapwa kwemhedzisiro yebvunzo yemhedzisiro bvunzo ichaenderana neGB/T 229-2007 "Charpy Pendulum Impact Test Method yeMetallic Materials" Kuita kwemaitiro ekukanganisa akachekwa kubva kune imwechete yekukanda test block (tsvimbo) uye yakasungirirwa yekukanda test block (tsvimbo) inofanira kusangana zvinodikanwa zveiyo inoenderana yekukanda mwero kana chibvumirano chekuraira. Izvo zvinodikanwa zvekuita zvesample yemuviri zvichakurukurwa nemutengesi uye mutengi zvinoenderana neinoenderana yekukanda mwero.

 

3. Kuoma

Pane nzira mbiri dzakajairwa dzekuona kuomarara kwekukandwa: Brinell kuomarara nzira uye Rockwell kuomarara nzira. Hard and brittle casting alloys anowanzo kuyerwa neRockwell kuoma nzira, uye mamwe maalloys ekukanda anowanzo kuyerwa neBrinell kuoma nzira. Kune akakandwa alloys ane yunifomu metallographic chimiro senge simbi yakakandwa, kune humwe hukama hwekushandura pakati peRockwell kuoma, kuomarara kweBrinell uye kusimba kwekusimba. Tarisa kune GB/T112-199 "Ferrous Metal Hardness uye Simba Conversion Value" uye GB / T 3771-1983 "Copper alloy kuoma uye simba rekushandura kukosha".

Nzira yeBrinell yekuomarara inoshandisa simende bhora recarbide rine dhayamita yakati kuritsikirira pamusoro pesample nesimba rekuyedza rinoenderana. Mushure menguva yakatarwa yekubata, bvisa simba rekuedza, kuyera dhayamita ye indentation pamusoro pemuenzaniso, uye patsanura simba rekuedza nekuedza simba. The quotient yakawanikwa kubva kuspherical surface area ye indentation inomiririra Brinell hardness value, uye chiratidzo iHBW, iyo inokodzera zvinhu zvine Brinell kuomarara kukosha kushoma kana kuenzana ne650. Zviridzwa, samples, nzira dzekuyedza uye mhinduro dzebvunzo. yeBrinell kuomarara bvunzo ichaenderana neGB/T 231.1-2002 "Metal Brinell Hardness Chikamu I: "Test Method". Muedzo wekuomarara kweBrinell unogona kuitwa pazviyero zvekusimba, zvimiro zvekukandira kana kunyanya kuomeswa zvidhinha kana kutaurirana nemutengesi nemutengi Iyo Rockwell kuoma nzira ndeyekutsikirira dhaimondi cone indenter kana bhora resimbi mukati meiyo sampuli pasi pechiito che. kutakura kwekutanga uye mutoro wose (yakaenzana nemutoro wekutanga pamwe nemutoro mukuru), uye wobvisa mutoro mukuru, uye kuyera pamutoro wekutanga. Kudzika kwemukati pasi pemutoro kunowedzera kukosha kwe e, uye kukosha kwe e kunoshandiswa kuverenga kuoma kweRockwell.

Iyo Rockwell kuoma kunosiyana zvichienderana nechiyero chakashandiswa. Zviyero zvinonyanya kushandiswa ndezveHRA, HRB uye HRC. HRB inotora indenter yesimbi ine kuoma kukosha = 130-c; HRA neHRC vanotora dhaimondi cone indenter ine kuoma kukosha=100-e. Mutoro mukuru weHRA ndeye 490.3N, uye chiyero chekuyera chiri 60 ~ 85HRA; mutoro mukuru weHRC ndeye 1373N, uye kuyerwa kwechiyero ndeye 20 ~ 67HRC. Zviridzwa, zvienzaniso, mamiriro ebvunzo uye nzira dzekuyedza dzinoshandiswa muRockwell kuomarara bvunzo, pamwe nekurapwa kwemhedzisiro yebvunzo ichaenderana neGB/T 230.1-2004 "Metal Rockwell Kuoma Chikamu 1: Test Method (A, B, C). , D, E, F, G, H, K, N, T Scale)". Kusarudzwa kwemuenzaniso, nzvimbo yekuyedza uye zvinodiwa zvehunyanzvi zveiyo bvunzo nzvimbo yeRockwell kuomarara bvunzo zvakafanana neyeiyo Brinell kuomarara bvunzo.

Pamusoro pekuoma kweBrinell uye Rockwell kuoma, kuoma kwesimbi kunogonawo kumiririrwa neShore hardness (HS) uye Vickers hardness (HV). Kuyera kuoma kweShore kwesimbi kunofanirwa kusangana nezvinodiwa zveGB/T 4341-2001 "Metal Shore Hardness Test Method". Kutsunga kweVickers kuoma kwesimbi kunofanirwa kusangana nezvinodiwa zveGB/T 4340.1-1999 "Metal Vickers Hardness Test Part 1: Test Method". Mhando dzakasiyana-siyana dzekuomarara dzinofanirwa kugaro simbiswa nedhipatimendi renyika remetroology zvinoenderana nezvinodiwa.