?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=EFEK+PRESTRAIN+PADA+BAJA+AISI+1020+TERHADAP+PERAMBATAN+%0D%0A++++RETAK+FATIK%0D%0A&rft.creator=BUDI+TRI+UTAMI%2C+1115021014&rft.subject=Teknik+mesin+dan+mesin&rft.description=Penelitian+perambatan+retak+fatik+baja+AISI+1020+yang+mengalami+prestrain+sebesar+30%25+dilakukan+menggunakan+mesin+MTS+Landmark+100+kN%2C+dengan+parameter+pengujian+R%3D0%2C3%2C+P_maks%3D+0%2C7P_yield%2C+dan+f%3D10+Hz+dengan+kondisi+pengujian+pada+temperatur+ruang.+Hasil+uji+tarik+menunjukkan+bahwa+efek+prestrain+meningkatkan+nilai+tegangan+luluh%2C+namun+kekuatan+tarik+maksimum%2C+modulus+elastisitas+dan+elongasinya+menurun.+Hal+ini+dikarenakan+deformasi+plastis+terjadi+pada+baja+AISI+1020+dalam+arah+aksial.+Laju+perambatan+retak+fatik+baja+AISI+1020+yang+tidak+di+prestrain+adalah+da%2FdN%3D+8%2C107%EF%82%B410-14%CE%94K4%2C69+dan+yang+di+prestrain+adalah+da%2FdN%3D+4%2C338%EF%82%B410-9%CE%94K1%2C49.+Berdasarkan+nilai+laju+perambatan+retak+fatik+prestrain+menurunkan+nilai+laju+perambatan+retak+fatik+baja+AISI+1020.+SEM+fraktografi+patahan+permukaan+baja+setelah+di+uji+fatik+pada+awal+retak+menghasilkan+bentuk+patahan+berupa+cekungan-cekungan+kecil+(dimple)+pada+siklus+25.000+dan+panjang+retak+1%2C6+mm.+Pada+permukaan+perambatan+retak+sekitar+12+mm+dan+siklus+42.000+permukaan+patahan+adalah+intergranular.+Pola+patahan+perambatan+retak+yang+cepat+terjadi+pada+siklus+43.500+dengan+panjang+retak+18%2C1+mm%2C+setelah+itu+spesimen+mengalami+patah+statis+pada+siklus+43.549.+%0D%0A%0D%0AKata+Kunci+%3A+prestrain%2C+perambatan+retak+fatik%2C+deformasi+plastis%2C+retak+intergranular.%0D%0A%0D%0A%0D%0A%0D%0AABSTRAK+BAHASA+INGGRIS%0D%0A%0D%0AIn+the+present+research%2C+the+fatigue+crack+growth+(FCG)+of++AISI+1020+steel+having+the+total+of+30%25+prestrain+was+carried+out+using+MTS+Landmark+100+kN+under+testing+parameters+load+rasio+(R)+%3D+0.3%2C+Pmax+%3D+0.7%E3%80%96%EF%82%B4P%E3%80%97_yield%2C+and+f+%3D+10+Hz+at+room+temperature.+Tensile+test+result+showed+that+the+prestrain+increased+of+the+value+of+the+yield+stress.+In+contrast%2C+the+ultimate+tensile+strength%2C+modulus+of+elasticity%2C+and+elongation+decreased.+The+FCG+rate+(da%2FdN+)+of+AISI+1020+steel+without+prestrain+is+8.107%EF%82%B410-14%CE%94K4.69+mm%2Fcyles+and+4.338%EF%82%B410-9%CE%94K1.49+mm%2Fcyles+with+prestrain.+According+to+microstructural+observation+for+the+steel+experieing+the+30%25+prestrain%2C+the+plastic+deformation+formed+on+the+steel+in+the+axial+direction+affected+the+FCG+rate+of+the+steel%2C+leading+to+crack+retardation+for+a+certain+periods+time.+SEM+fractographic+observation+on+the+fracture+surface+of+the+steel+after+FCG+testing+when+the+crack+reached+around+1.6+mm+at+25%2C000+cycles%2C+shows+a+dimpels+fracture.+Moreover%2C+the++intergranular++crack+was+observed+by+the+crack+length+of+12+mm+at+42%2C000+cycles.+The+steel+failed+when+the+crack+length+was+around+18.1+mm+with+the+total+of+43%2C500+cycles.+At+the+total+of+43%2C549+cyles%2C+the+steel+showed+static+failure.%0D%0AKeywords%3A+prestrain%2C+fatigue+crack+growth%2C+plastic+deformation%2C+intergranular+crack.%0D%0A&rft.publisher=UNIVERSITAS+LAMPUNG&rft.date=2016-06-09&rft.type=Skripsi&rft.type=NonPeerReviewed&rft.format=text&rft.identifier=http%3A%2F%2Fdigilib.unila.ac.id%2F22850%2F1%2FABSTRAK%2520BAHASA%2520INGGRIS%2520%2526%2520INDONESIA.pdf&rft.format=text&rft.identifier=http%3A%2F%2Fdigilib.unila.ac.id%2F22850%2F3%2FSKRIPSI%2520FULL.pdf&rft.format=text&rft.identifier=http%3A%2F%2Fdigilib.unila.ac.id%2F22850%2F2%2FSKRIPSI%2520TANPA%2520BAB%2520PEMBAHASAN.pdf&rft.identifier=++BUDI+TRI+UTAMI%2C+1115021014++(2016)+EFEK+PRESTRAIN+PADA+BAJA+AISI+1020+TERHADAP+PERAMBATAN+RETAK+FATIK.++UNIVERSITAS+LAMPUNG%2C+FAKULTAS+TEKNIK.+++++&rft.relation=http%3A%2F%2Fdigilib.unila.ac.id%2F22850%2F