Mechanical properties of modified cast martensitic stainless steel CA6NM with addition of molybdenum and nitrogen

Primatama

et al. 2020

JTBBT

Self Cite

This research was aimed to do heat treatment of austemper carburization and investigate the effect of various cooling media on mechanical properties and microstructure of Cr-Mo alloy lateritic steel. Heat treatment was conducted to austenisation temperature at 950o C for 1 hour and austemper carburization at 400o C for 1 hour. Variation of cooling media included air blowing for 1 hour, water, and furnace cooling for 24 hours. Hardness and impact test were done using Hardness Rockwell and Charpy methods. Microstructure was observed using optical microscope. Fracture surface characterization was using SEM-EDX. The results showed the highest hardness of 65.48 HRC in sample that cooled by air blowing for 1 hour. The microstructure of this sample showed phases of ferrite, pearlite and martensite which causing higher hardness. The highest impact strength of 20 Joule took place in the furnace cooled sample. Characterization of the fracture surface using SEM-EDX showed dimple of ductile fractures.Penelitian ini bertujuan untuk melakukan proses perlakukan panas karburisasi austemper dan mempelajari pengaruh media pendinginan terhadap sifat mekanik dan struktur mikro baja laterit paduan Cr-Mo. Perlakuan panas yang dilakukan yaitu pemanasan sampel pada temperatur austenisasi (950o C) selama 1 jam dan proses karburisasi austemper dengan media serbuk arang halus pada temperatur 400o C selama 1 jam. Variasi pendinginan yang digunakan yaitu air blowing (semburan udara) selama 1 jam, air dan tungku selama 24 jam. Pengujian kekerasan dilakukan dengan metode Rockwell Hardness dan pengujian impak dilakukan dengan metode charpy. Karakterisasi struktur mikro dilakukan dengan proses metalografi dan mikroskop optik. Karakterisasi permukaan patahan pengujian impak dilakukan dengan SEM-EDX. Hasil penelitian ini menunjukkan nilai kekerasan tertinggi yaitu 65,48 HRC terjadi pada sampel dengan air blowing selama 1 jam. Struktur mikro sampel tersebut menunjukkan adanya fasa ferit, perlit dan martensit yang membuat sampel menjadi keras. Nilai kekuatan impak tertinggi sebesar 20 Joule terjadi pada sampel dengan pendinginan di dalam tungku selama 24 jam. Karakterisasi permukaan patahannya menggunakan SEM-EDX menunjukkan adanya dimple dari patah ulet.

Section: Pendahuluanunclassified

Pengaruh Perlakuan Panas Karburisasi Austemper pada Baja Laterit Paduan Cr-Mo terhadap Sifat Mekanik dan Struktur Mikro

Herbirowo

Primatama

et al. 2020

JTBBT

Self Cite

“…Kegagalan yang umum terjadi pada komponen ini dikarenakan retakan yang terjadi akibat interaksi antara tegangan yang tinggi dan lingkungan korosif pada sistem turbin [5]. Oleh karena itu, modifikasi unsur kimia dan perubahan struktur mikro baja melalui perlakuan panas diharapkan dapat meminimalisir kegagalan material BTK AISI 410 pada aplikasi turbine blade [6].…”

Section: Pendahuluanunclassified

Pengaruh Annealing terhadap Sifat Keras dan Struktur Mikro Baja Tahan Karat AISI 410-3Mo-3Ni

Prasetyo

Halab

et al. 2020

metal.

Self Cite

AISI 410-3Mo-3Ni stainless steel is a martensitic steel which limited in using when compared to austenitic and ferritic stainless steels. Martensitic steel has an essential role in specific components due to a combination of strength, toughness and excellent corrosion resistance. However, martensitic steel tends to undergo decreasing in mechanical properties and microstructure after the forging process. In this study, mechanical properties and microstructure of the forged AISI 410 after receiving annealing heat treatment will be studied. Annealing aims to reduce material hardness and increase grain refinement of material. Annealing heat treatment is carried out by varying the annealing temperature and time. Annealing temperature variations are 7000, 7600, and 8000C. The annealing time variation is 3 hours and 6 hours. The effect of annealing time and temperature will be studied on the hardness and microstructure of the AISI 410 modified material. The optimum hardness of 35.9 HRC in sample with annealing treatment in 760°C for 6 hours. The microstructure shows delta ferrite, martensite, austenite, and carbide phases which affect hardness value of annealed samples.

“…Kekuatan tarik minimum diperoleh pada sampel baja laterit dengan proses pengerolan panas menggunakan reduksi 20% yaitu 864 MPa. Beberapa faktor yang mempengaruhi kekuatan tarik yaitu suhu pemanasan, laju pendinginan, serta transformasi struktur mikro dan senyawa yang terbentuk [23]. Nilai kekuatan tarik yang paling kecil terjadi pada sampel dengan reduksi 20% dikarenakan butir yang semakin besar (mengalami fenomena grain growth) terlihat pada Gambar 7.…”

Section: Hasil Pengujian Kekuatan Tarikunclassified

Pengaruh Variasi Persentase Reduksi pada Proses Pengerolan Panas terhadap Sifat Mekanik dan Struktur Mikro Baja Laterit

Paristiawan

Pramono

et al. 2020

JRM

Self Cite

Lateritic ore is one of the raw materials for the steel industry. Lateritic ore processed into laterite steel has more advantages than steel in the market. It has better tensile strength, hardness, corrosion resistance, and welding properties. Lateritic steel is made by performing a casting process. This research aims to investigate the effect of reduction percentage on mechanical properties and microstructure of the lateritic steel after the hot rolling process. The specimens were heated to austenitization temperature at 1000 0 C for 1 hour before the rolling process. The reduction percentage varies by 10%, 15%, and 20%. Hardness and impact test was conducted using a Rockwell Hardness and Charpy method. The microstructure was observed using an optical microscope. The results showed the optimum hardness of 58 HRC in a hot rolling sample with 20% reduction. The highest impact strength of 46 Joule and ductile fracture took place in this sample. The microstructure of this sample showed a bainitic phase causing lower hardness.