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Thursday, December 22, 2016
Tulisan Gus Dur Terkait Harlah, Natal, dan Maulid
Sunday, December 11, 2016
Vikings Earlander Ragnar Lodbrok
Thursday, November 17, 2016
Wear Rate of Metals (AISI 630)
Present work aimed at investigating the wear resistance of AISI 630 (UNS S17400) or 17-4 PH stainless steel hardened by precipitation hardening or aging at various hardness levels.
The PHs steels are an interesting family of steels for applying in highly stressed parts for its corrosion resistance and relative high hardness, attaining up to 49 HRC by low-temperature aging heat treatment, low distortion and excellent weldability.
The wear tests by sliding and/or abrasion were performed in a pin-on-disc tribometer whose pins had three different hardness levels (43, 37 and 33 HRC) obtained by varying the precipitation hardening treatment. The counterface discs were machined from the same steel composition and aged to the hardness of 43 HRC.
The steels wear resistances were evaluated, using sliding velocity of 0.6 m/s, normal load of 30 N, total sliding distance of 2400 m and controlled room temperature and humidity of 27 °C and 60%, respectively.
From the analysis of plotted graphs of cumulative lost volume versus sliding distance, it was observed the different wear rates as function of the heat treatment and hardness. Due to the pins different hardness, the wear resistance varied substantially.
The wear mechanisms were also investigated through scanning electron microscopy observations of the worn surfaces of the pins. It can be asserted that the decrease in the pin hardness yields to lower pin wear resistance.
The disc wear was more severe as the difference in hardness between pin and disc increased. It was presented a list of mean wear resistance, establishing the best heat treatment that minimize the wear in this material for sliding wear applications.
For the investigated range of heat treatment and hardness, the 17-4 PH steel pins with hardness of 43 HRC showed the best wear resistance of 1941 and the pin with 33 HRC the worst wear resistance of 1581.
Keywords
Wear testWear resistancePH stainless steelHeat treatment
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Corresponding author. Tel.: +55 47 4009 7958; fax: +55 47 4009 7940.
Tuesday, November 8, 2016
AISI 52100 Specification
ASTM A295 is specification which covers 52100 high carbon bearing quality steel to be used in the manufacture of anti-friction bearings. And 52100 bearing steel is the most common steel grade in ASTM A295 standard for high-carbon anti-friction bearing steel.
What is 52100 bearing steel?
AISI/ASTM 52100 bearing steel is a high carbon, chromium containing low alloy steel that is through hardening and noted in particular for use as bearings.astm aisi 52100 bearing steel
52100 bearing steel is one kind of special steel with features of high wear resistance and rolling fatigue strength. High-carbon chromium bearing steel, engineering steel and some types of stainless steel and heat resistant steel are used as materials of bearings and for other purposes.
Advantages of Chrome Bearing Steel 52100:
Superior hardness, 60-67 on Rockwell hardness scale (Rc) at room temperature
High carbon chrome alloy steel
Operates continually at temperatures up to 120°C
Used to produce precision ball bearings and roller bearings
Cost-effective
Long working life
1. Supply Range of ASTM 52100 Bearing Steel
AISI 52100 Steel Round Bar: diameter 8mm – 800mm
52100 Steel Plate: thickness 2mm –300mm x width 200mm – 800mm
Other sizes of 52100 steel as per customer’s requirements
Process: Cold drawn, hot rolled, forged etc.
Surface Finish: black, rough machined, turned, polished or as per given requirements.
2. Relevant Steel Specification of ASTM 52100 Bearing Steel
Country USA German Japan British
Standard ASTM A295 DIN 17230 JIS G4805 BS 970
Grades 52100 100Cr6/1.3505 SUJ2 535A99/EN31
3. Chemical Composition of 52100 Bearing Steel and Equivalents
Standard Grade C Mn P S Si Ni Cr Cu Mo
ASTM A295 52100 0.93-1.05 0.25-0.45 0.025 0.015 0.15-0.35 0.25 1.35-1.60 0.30 0.10
DIN 17230 100Cr6/1.3505 0.90-1.05 0.25-0.45 0.030 0.025 0.15-0.35 0.30 1.35-1.65 0.30 –
JIS G4805 SUJ2 0.95-1.10 0.50 0.025 0.025 0.15-0.35 – 1.30-1.60 – –
BS 970 535A99/EN31 0.95-1.10 0.40-0.70 – – 0.10-0.35 – 1.20-1.60 – –
4. Mechanical Properties of ASTM A295 52100 Bearing Steel
Properties Metric Imperial
Bulk modulus (typical for steel) 140 GPa 20300 ksi
Shear modulus (typical for steel) 80 GPa 11600 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson’s ratio 0.27-0.30 0.27-0.30
Hardness, Brinell – –
Hardness, Knoop (converted from Rockwell C hardness) 875 875
Hardness, Rockwell C (quenched in oil from 150°C tempered) 62 62
Hardness, Rockwell C (quenched in water from 150°C tempered) 64 64
Hardness, Rockwell C (quenched in oil) 64 64
Hardness, Rockwell C (quenched in water) 66 66
Hardness, Vickers (converted from Rockwell C hardness) 848 848
Machinability (spheroidized annealed and cold drawn. Based on 100 machinability for AISI 1212 steel) 40 40
52100 Steel Physical Properties
Properties Metric Imperial
Density 7.81 g/cm3 0.282 lb/in³
Melting point 1424°C 2595°F
52100 Alloy Steel Thermal Properties
Properties Metric Imperial
Thermal expansion co-efficient (@ 23-280°C/73.4- 36°F, annealed) 11.9 µm/m°C 6.61 µin/in°F
Thermal conductivity (typical steel) 46.6 W/mK 323 BTU in/hr.ft².°F
5. Forging of A295 52100 Bearing Steel
AISI 52100 alloy steel is forged at 927 to 1205°C, and should not be forged below 925ºC. A post-forge equalization treatment is recommended at 745ºC for 4-6 hours followed by air cooling for SAE/AISI 52100 steel.
6. Heat Treatment for ASTM 52100 Bearing Steel
ASTM/AISI 52100 alloy bearing steel is heated at 816°C followed by quenching in oil. Before performing this process, it is subjected to normalizing heat treatment at 872°C followed by slowly cooling in order to reduce the machining stress.
Hot Working
AISI 52100 bearing steels alloy can be hot worked at 205 to 538°C.
Cold Working
AISI 52100 bearing steel can be cold worked using conventional techniques in the annealed or normalized conditions.
Annealing
For spheroidize anneale, the following isothermal anneal is recommended:
1500ºF (815ºC) for 3 hours
1350ºF (735ºC) for 4 hours
1250ºF (675ºC) for 3 hours
Slow cool to 1000ºF (540ºC) then air cool.
Quenching
AISI 52100 alloy bearing steel could be hardened by quenching in water from 801-829 degree or quench in oil from 816-842 degree.
Tempering
Temper to desired hardness as indicated by tempering curves after water or oil quench.
7. Applications of 52100 Bearing Steel
Alloy steel 52100 grade bearing steel is mainly used for the manufacture of aircraft bearings and other highly stressed parts. This steel grade 52100 steel is preferably vacuum arc re-melted to give optimum performance.
Typical applications: Bearing Manufacture, CV joints, ball screws, gauges, knife etc.
Otai Steel is one of reliable and serious special steel supplier of 52100 bearing steel materials. We stock and export such bearing steels worldwide. In the end of each month, we may have some 52100 bearing steel materials for sale or in discount. You are free to request a 52100 bearing steel price anytime.
Monday, October 31, 2016
Es Buah Pembawa Rejeki
Friday, October 28, 2016
Manfaat Donor Darah Bagi Kesehatan Pendonor
Penulis Donor Darah di PMI Bekasi |
Wednesday, October 26, 2016
Tips Aman dan Selamat Pendakian Gunung
Leave nothing but footprints.
Kill nothing but time."
Tidak meninggalkan sesuatu selain jejak.
Tidak membunuh sesuatu selain waktu."
Puncak Gunung Slamet 10.774 feet, Jateng. |
Tuesday, October 25, 2016
100 Years NSK Bearings Manufacturing
Logo Anniversary 100 Years NSK |
Wednesday, September 21, 2016
Kelemahan BPJS Kesehatan
Kekurangan pertama dari BPJS Kesehatan adalah adanya metode berjenjang saat melakukan klaim. Di BPJS, di luar keadaan darurat, peserta memang diharuskan memeriksakan penyakitnya ke faskes 1 terlebih dahulu. Faskes 1 ini sendiri berupa puskesmas atau klinik. Setelah dari di faskes 1 dan pasien memang dirasa harus ke rumah sakit, maka pasien atau peserta BPJS baru bisa ke rumah sakit yang bekerja sama dengan BPJS. Namun di asuransi lain, Anda bisa langsung memeriksakan sakit ke rumah sakit yang sudah bekerja sama.
Layanan kesehatan BPJS memang hanya bisa melindungi diri di wilayah Indonesia saja. Berbeda dengan asuransi swasta yang bisa memproteksi kesehatan pesertanya di rumah sakit yang bekerja sama hingga di seluruh dunia atau mancanegara.
Untuk Anda yang akan mendaftar atau akan melakukan pengubahan data di kantor BPJS, maka Anda harus bersiap dengan antrian yang panjang. Tidak hanya dalam hal mendaftar dan melakukan perubahan data, ketika peserta juga akan berobat ke rumah sakit, maka antrian panjang juga harus dihadapi peserta.
Terakhir, kekurangan BPJS Kesehatan adalah tidak adanya kesempatan untuk mendapat fasilitas kelas 1. Meskipun peserta telah mendaftar pada kelas 1 dan 2 namun pada kenyataan di lapangan memang terjadi hal yang tidak sesuai. Mereka para peserta BPJS Kesehatan ini sering mendapat fasilitas kelas 3.
Thursday, September 15, 2016
Sistem Manajemen K3 (Kesehatan dan Keselamatan Kerja)
• Untuk tingkat pencapaian penerapan 60 – 84% termasuk tingkat penilaian penerapan Baik.
• Untuk tingkat pencapain 85 – 100% termasuk tingkat penilaian penerapan memuaskan.
- PLAN (Perencanaan) : Menetapkan sasaran dan proses yang diperlukan untuk mencapai hasil sesuai kebijakan K3 perusahaan.
- DO (Pelaksanaan) : Pelaksanaan proses.
- Check (Pemeriksaan) : memantau dan mengukur kegiatan proses terhadap kebijakan, sasaran, peraturan perundang-undangan dan persyaratan k3 lainnya serta melaporkan hasilnya.
- ACTION (Tindakan) : mengambil tindakan untuk perbaikan kinerja k3 secara berkelanjutan.
Friday, March 11, 2016
Opini: RAT Koperasi Karyawan PT. NSK BMI
Logo Kopkar NSK |
Tulisan ini adalah mutlak pendapat atau opini penulis dalam menilai atau menyikapi RAT Kopkar (Koperasi Karyawan) PT. NSK BMI yang mana penulis adalah bagian dari anggota koperasi sekaligus sebagai karyawan PT. NSK BMI itu sendiri. Penulis berkeinginan memberikan sebuah penilaian yang bisa saja akan dipandang obyektif dan tidak menutup kemungkinan akan terlihat subyektif. Untuk mendukung agar tulisan ini mendekati obyektif maka penulis berusaha memakai data-data atau pertanyaan secara langsung kepada anggota koperasi yang lain, khususnya tentang proses pelaksanaan RAT 2016 ini.
Friday, January 29, 2016
Daftar Balai Laboratorium Pengujian Logam
Balai Besar Bahan dan Barang Teknik
Sucofindo
Polman Bandung
BPPT Serpong
Departemen Metalurgi UI Depok
Departemen Metalurgi dan MaterialFakultas Teknik Universitas Indonesia
Kampus UI Depok 16424 Jawa Barat - Indonesia
Telepon : + 62 – 21 – 786 3510
Fax : + 62 – 21 – 787 2350
Email : info@metal.ui.ac.id