Metal Properties: Total ElongationNovember 1, 2022
Metal certs document the tensile properties of your purchased coils. Elongation is one measure of ductility, as denoted by the E in the YTE abbreviation. This article discusses elongation at fracture and elongation after fracture, with both distinct from uniform elongation—a topic for a future article.
Higher elongation values are associated with metal alloys better able to form deeper draws without necking or splitting. Elongation also influences other mechanical behavior. Usually, higher elongation and lower yield strength trend together, but the material grade significantly influences this correlation. Deformation on the outer bend surface is comparable to what occurs during tensile testing. Comparing elongation values between different grades may provide a good estimate of their relative bendability. Alloys with higher elongation values accommodate greater rollover before fracture with some benefit in cut-edge ductility. Stronger influences include the microstructure and strength level of the sheet metal, and the cut-edge quality produced at the manufacturing facility.
Although seemingly a simple concept, more goes into determining the elongation value than many realize.
Tensile Dogbone Standard Shapes
The tensile-test sample, called a dogbone due to its characteristic shape, contains a section of reduced width typically 60 to 120 mm long. All measurements for elongation occur within the central portion of this reduced section, called the gauge length. Elongation calculations are expressed as a percentage change in length from a gauge length of either 50 or 80 mm long. For example, if pulling the sample results in a gauge-length increase to 60 mm with a length before testing of 50 mm, then the elongation calculates as 20 percent.
Standards-writing organizations such as ASTM, DIN, JIS and ISO each have requirements for tensile-testing procedures, calling out the shapes of the test-sample dogbones (Fig. 1).
Uwezo wa Metal: Urefu wa Jumla Novemba 1, 2022 Cheti cha Chuma kinarekodi mali ya mvuto ya coils zako zilizonunuliwa. Urefu ni kipimo kimoja cha ductility, kama inavyoonyeshwa na E katika kifupi cha YTE. Makala hii inazungumzia elongation katika fracture na elongation baada ya fracture, na wote tofauti na elongation sawa <unk> mada kwa ajili ya makala ya baadaye. Thamani ya juu ya upanuzi ni kuhusishwa na alloys chuma bora uwezo wa kuunda draws kina bila necking au kugawanyika. Kuinuka pia huathiri tabia nyingine za mitambo. Kwa kawaida, upanuzi wa juu na mwelekeo wa chini wa nguvu ya mavuno pamoja, lakini darasa la nyenzo huathiri sana uhusiano huu. deformation juu ya nje bend uso ni kulinganishwa na nini hutokea wakati wa mtihani tensile. Kulinganisha maadili elongation kati ya madarasa tofauti inaweza kutoa makadirio mazuri ya bendability yao ya jamaa. Aloi na thamani ya juu ya upanuzi kukaribisha rollover kubwa kabla ya kuvunjika na baadhi ya faida katika kukata-kando ductility. Uvutano mkubwa ni pamoja na microstructure na nguvu ngazi ya karatasi ya chuma, na ubora cut-kingo zinazozalishwa katika kituo cha utengenezaji. Ingawa inaonekana kuwa dhana rahisi, kuna mengi zaidi yanayohusika katika kuamua thamani ya kunyoosha kuliko wengi wanavyojua. Mfano wa mtihani wa mvuto, unaoitwa dogbone kwa sababu ya umbo lake la tabia, una sehemu ya upana uliopunguzwa, kawaida urefu wa 60 hadi 120mm. Vipimo vyote vya urefu hutokea ndani ya sehemu ya kati ya sehemu hii iliyopunguzwa, inayoitwa urefu wa kipimo. Urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu wa urefu. Kwa mfano, ikiwa kuondoa sampuli husababisha urefu wa kipimo kuongezeka hadi 60mm na urefu kabla ya mtihani wa 50mm, basi urefu unahesabiwa kama asilimia 20. Mashirika ya kuandika viwango kama vile ASTM, DIN, JIS na ISO kila mmoja ana mahitaji ya taratibu za majaribio ya mvuto, akitoa maumbo ya mifupa ya mbwa ya sampuli ya majaribio (Fig. 1)