?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=PENGARUH+DOUBLE+QUENCHING+AND+TEMPERING+TERHADAP%0D%0APERUBAHAN+SIFAK+MEKANIK+DAN+STRUKTUR+MIKRO+BAJA+AISI%0D%0A%0D%0A4140&rft.creator=RIYANSYAH+PUTRA+PRATAMA%2C+1415021075&rft.subject=620+Ilmu+teknik+dan+ilmu+yang+berkaitan&rft.description=Baja+AISI+4140+banyak+digunakan+dalam+konstruksi+mesin+karena+memiliki+sifat%0D%0Aulet+mudah+dibentuk%2C+kuat+maupun+keras.+Baja+AISI+4140+merupakan+baja+karbon%0D%0Asedang+(0.38+%E2%80%93+0.43+wt.%25+C)+dengan+elemen-elemen+pemadu+lainya%3A+0.80%25+-%0D%0A1.1%25+Cr%2C+0.75%25+-+1.0%25+Mn%2C+%3C+0.040%25+S%2C+0.15%25+-+0.3%25+Si%2C+%3C+0%2C035%25+P+dan%0D%0A0.15%25+-+0.25%25+Mo.+Salah+satu+cara+untuk+meningkatkan+sifat+mekanik+baja+AISI%0D%0A4140+melalui+proses+Q%26T.+Q%26T+adalah+proses+memanaskan+baja+hingga%0D%0Atemperatur+austenit%2C+selanjutnya+baja+ditahan+pada+furnace+dengan+lama+waktu%0D%0Atertentu+dan+didinginkan+secara+cepat+dengan+air+atau+media+tertentu%2C+selanjutnya%0D%0Abaja+dipanaskan+kembali+dibawah+suhu+austenit+dan+di+tahan+pada+waktu+tertentu%0D%0Ayang+selanjutnya+didinginkan+secara+perlahan+pada+suhu+ruangan.+Untuk+itu+pada%0D%0Apenelitian+pengaruh+double+quenching+and+tempering+terhadap+sifat+mekanik%0D%0Adilakukan+untuk+meningkatkan+nilai+ketangguhan.+Pada+proses+ini+dilakukan+3%0D%0Avariabel+yaitu+Uji+Tarik%2C+Uji+Struktur+Mikro%2C+dan+Uji+SEM.+Hasil+dari+penelitian%0D%0Aini+kekuatan+tarik+double+quenching+dan+1+kali+quenching+memilik+keuletan+yang%0D%0Arendah+atau+memiliki+sifat+getas%2C+sedangkan+kekuatan+tarik+double+tempering+dan%0D%0A1+kali+tempering+memiliki+keuletan+yang+tinggi.+Maka+proses+double+quenching%0D%0Adan+tempering+tidak+terlalu+merubah+kekuatan+tarik+dan+keuletan+baja+karena%0D%0Ahasilnya+sama+dengan+1+kali+pemanasan.+Pada+pengujian+observasi+microscopy%0D%0Abaja+AISI+4140+yang+tidak+di+heat+treatment+mengandung+pearlit+dan+ferrit.+Pada%0D%0Aspesimen+yang+di+quenching+dan+double+quenching+memiliki+struktur+martensit%0D%0Adan+memiliki+permukaan+yang+cukup+kasar.+Pada+spesimen+yang+di+tempering+dan%0D%0Adouble+tempering+memiliki+struktur+temper+martensit+dan+memiliki+permukaan%0D%0Ayang+cukup+halus.+Pada+pengujian+Scanning+Electron+Microscopy+(SEM)+terlihat%0D%0Ahanya+muncul+dimple+dan+clavage.+ini+membuktikan+bahwa+spesimen+baja+AISI%0D%0A4140+memiliki+sifat+tangguh.%0D%0A%0D%0AKata+kunci%3A+Baja+AISI+4140%2C+Quenching%2C+Tempering%2C+Uji+Tarik%2C+Struktur+Mikro%0D%0Adan+SEM%0D%0AAISI+4140+steel+is+often+used+in+engine+construction+because+it+has+resilient%0D%0Aproperties+that+are+easily+formed%2C+strong+or+hard.+AISI+4140+steel+is+medium%0D%0Acarbon+steel+(0.38+-+0.43+wt.%25+C)+with+other+elements%3A+0.80%25+-+1.1%25+Cr%2C+0.75%25+-%0D%0A1.0%25+Mn%2C+%3C0.040%25+S%2C+0.15%25+-+0.3%25+Si%2C+%3C+0.035%25+P+and+0.15%25+-+0.25%25+Mo.+One%0D%0Aof+to+improve+the+mechanical+properties+of+AISI+4140+steel+through+the+Q+%26+T%0D%0Aprocess.+Q+%26+T+is+the+process+of+heating+steel+to+the+temperature+of+austenite%2C+then%0D%0Athe+steel+is+held+in+a+furnace+with+a+certain+time+and+cooled+quickly+with+water+or%0D%0Acertain+media%2C+then+the+steel+is+heated+again+under+the+austenite+temperature+and%0D%0Aheld+at+a+certain+time+which+is+then+cooled+slowly+at+room+temperature.+For+this%0D%0Areason%2C+the+double+cooling+effect+and+tempering+on+mechanical+properties+are%0D%0Acarried+out+to+increase+the+toughness+value.+In+this+process+3+variables+are+carried%0D%0Aout%3A+Tensile+Test%2C+Micro+Structural+Test%2C+and+SEM+Test.+The+results+of+this+study%0D%0Adouble+quenching+tensile+strength+and+1+quenching+have+low+tenacity+or+brittle%0D%0Aproperties%2C+while+double+tempering+tensile+strength+and+1+time+tempering+have%0D%0Ahigh+tenacity.+Then+the+double+quenching+and+tempering+process+does+not+change%0D%0Athe+tensile+strength+and+tenacity+of+steel+too+much+because+the+result+is+the+same+as%0D%0A1+time+heating.+In+the+AISI+4140+steel+microstructure+which+is+not+heat+treatment%0D%0Acontains+pearlite+and+ferrite.+Quenching+and+double+quenching+specimens+have+a%0D%0Amartensitic+structure+and+have+a+fairly+rough+surface.+Tempered+and+double%0D%0Atempering+specimens+have+a+martensitic+tempering+structure+and+have+a+fairly%0D%0Asmooth+surface.+In+Scanning+Electron+Microscopy+(SEM)+testing+it+appears+that%0D%0Aonly+appears+dimple+and+clavage.+this+proves+that+the+AISI+4140+steel+specimen%0D%0Ahas+tough+properties.%0D%0AKeywords%3A+AISI+4140+steel%2C+Quenching%2C+Tempering%2C+Tensile+test%2C+Micro+Structure%2C%0D%0Aand+SEM.&rft.publisher=FAKULTAS+TEKNIK&rft.date=2019&rft.type=Skripsi&rft.type=NonPeerReviewed&rft.format=text&rft.identifier=http%3A%2F%2Fdigilib.unila.ac.id%2F57076%2F1%2FABSTRAK.pdf&rft.format=text&rft.identifier=http%3A%2F%2Fdigilib.unila.ac.id%2F57076%2F2%2FSKRIPSI%2520FULL.pdf&rft.format=text&rft.identifier=http%3A%2F%2Fdigilib.unila.ac.id%2F57076%2F3%2FSKRIPSI%2520TANPA%2520BAB%2520PEMBAHASAN.pdf&rft.identifier=++RIYANSYAH+PUTRA+PRATAMA%2C+1415021075++(2019)+PENGARUH+DOUBLE+QUENCHING+AND+TEMPERING+TERHADAP+PERUBAHAN+SIFAK+MEKANIK+DAN+STRUKTUR+MIKRO+BAJA+AISI+4140.++FAKULTAS+TEKNIK%2C+UNIVERSITAS+LAMPUNG.+++++&rft.relation=http%3A%2F%2Fdigilib.unila.ac.id%2F57076%2F