scholarly journals PENGARUH QUENCHING DENGAN MEDIA PENDINGIN AIR DAN OLI TERHADAP MECHANICAL PROPERTIS BAJA S45C

JTAM ROTARY ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 183
Author(s):  
Deni Setiadi ◽  
Achmad Kusairi Samlawi
Keyword(s):  
Heat Treatment ◽  
High Hardness ◽  
Hardness Test ◽  
Water Cooling ◽  
Test Analysis ◽  
Cooling Medium ◽  
A Value ◽  
Before And After ◽  
Cooling Media

The role of steel in the industrial world today is very important, especially in terms of making components related to violence such as gears, fly wheel, axe, and so forth.This steel has a high hardness for components that require hardness, to uletan and resistance to friction. get hardness and resistance to steel hence need heat treatment process using Quenching process. The material of this research is S45C carbon steel with specimen number 1 for hardness test before treatment and after treatment with rockwell test, this process is done in Central Laboratory of FMIPA UM, unfortunate. In this process heat treatment is carried out at temperatures of 800⁰C and 900⁰C with water and oil cooling medium, from the results of comparative analysis on S45C steel before and after the treatment obtained increased hardness. This can be seen from the test analysis in which 93 kgf of hardness n is for the untreated specimens. At a temperature of 800⁰C with a water cooling medium at a crude value of 94.6 kgf, and on oil cooling medium at a hardness value of 92.5 kgf. At a temperature of 900⁰C with a water cooling medium at a hardness value of 93.5 kgf and on the oil cooling medium at a value of 93 kgf. Can be concluded from all the cooling media is the highest media water with value of violence 94.6 kgf.Keywords: S45C Steel, Quenching, Cooling

scholarly journals Pengaruh Media Pendingin Terhadap Kekerasan Baja Tahan Karat Martensitik Type 431 Pada Proses Hardening dan Tempering

2018 ◽  
Vol 1 (02) ◽  
pp. 27-32
Author(s):  
Suyanta Suyanta ◽  
Subagiyo Subagiyo ◽  
Syamsul Hadi ◽  
Zahratul Jannah
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Air Conditioning ◽  
Cutting Tool ◽  
High Hardness ◽  
Air Cooling ◽  
Water Cooling ◽  
Cooling Medium ◽  
Hardening Process ◽  
Cooling Media

Stainless steels consist of several types such as Austenitic, Ferritic and Martensitic, Martensitic is one of the stainless steels that has a hardenability property, so it is suitable to be used as cutting tool components which require high hardness and corrosion resistance . The purpose of this study was to obtain information about the hardness of stainless steel martensitic type of hardening results with variations of cooling media. Methods of research used were experiments, ie hardening process by heating the material up to 1100oC temperature, held for 30 minutes, then cooled quickly on water, oil and the air, then heated back to 400oC temperature, cooled slowly, the results tested the hardness of Rockwell C method The results showed the type of stainless steel type martensitic 431 increased significantly after the Hardening process of 21.20 HRC before hardening, and after the hardening process to 47 , 6 HRC with water cooling, 47.9 HRC with oil cooling medium and 46.5 HRC for air cooling media, hardness after tempering down ranges from 6-7 HRC to 41.7 HRC for hardening with water cooling medium 41, 2HRC hardening results with oil cooling medium, and 40,4HRC un tuk hardening results with air conditioning medium.

scholarly journals Analisa Pengaruh Variasi Media Pendingin Pada Proses HeatTreatment Metode Hardening-Tempering Material Baja S45C Terhadap Sifat Mekanik dan Struktur Mikro

2020 ◽  
Vol 15 (3) ◽  
pp. 199
Author(s):  
Aldi Wahyu Permana ◽  
Ratna Dewi Anjani ◽  
Iwan Nugraha Gusniar
Keyword(s):  
Heat Treatment ◽  
Salt Water ◽  
Coconut Water ◽  
Water Cooling ◽  
Cooling Medium ◽  
Research Activities ◽  
Hardening Process ◽  
Metal Metal ◽  
Cooling Media ◽  
Tempering Process

<p><em>In Our life, we always life with any tools and technology for improve our life. We can find many tools and other technolgy are made from metal. Of course, we need metals which have a characteristic for improve that inquiry, for example in terms of hardness in metal. Metal hardness can be increased in several ways. One of them is the hardening process. This process is a process of heat treatment of metal by heating and then cooling it to a certain temperature. In the traditional market, a lot of shredded coconut water is not used and can be used as a cooling medium in the hardening process. Therefore, the author will use the results of this wate shredded coconut water as a cooling medium for the hardening process.  Researchers  examined  the  effect  of  variations in heat  treatment  process  cooling media  on mechanical properties and microstructure with three variations of coolant. temperature 865 </em><em>⁰</em><em>C for hardening process and 465 C for tempering process. research activities include hardness and micro structure testing. The results showed that the hardening process salt water cooling medium had the highest hardness value of 275.6Hv while the lowest hardness was  obtained in the coconut water cooling medium  which had carried out the tempering process with a hardness of 219.3Hv. This is influenced by SOQ (Severity Of Quenching) or what is called the ability of the cooling media, for salt water the value is 5.0 for SOQ and for coconut water below 2.055. Meanwhile, for the microstructure, it can be seen that the hardening process brine cooling medium has a finer structure than the other cooling specimens. Meanwhile, in the tempering process, martensite turned into finer ferrite cementite with a hardness of 269.3Hv</em></p>

scholarly journals Pengaruh Perlakuan Panas Quenching dan Tempering terhadap Laju Korosi pada Baja AISI 420

2017 ◽  
Vol 1 (2) ◽  
pp. 19
Author(s):  
Sotya Anggoro
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Corrosion Rate ◽  
Base Material ◽  
Air Cooling ◽  
Corrosion Resistant ◽  
A Value ◽  
Aisi 420 ◽  
Quenching Process ◽  
Cooling Media

<p>Corrosion occurs in almost all metals. Even corrosion-resistant metals are corroded, but their corrosion rate is different from ordinary or non-corrosion resistant metals. This study examines the corrosion rate that occurs in stainless steel that is stainless steel. Stainless steel contains high enough chromium levels that can reduce the rate of corrosion that occurs. The metal material to be studied is the AISI 420 steel, which belongs to the Martensitic Stainless Steel class. This study examined the effect of heat treatment on corrosion rate and hardness level of AISI 420 steel. The heat treatment carried out was Quenching at 1020<sup>o</sup>C with a holding time of 60minutes with an oil cooling medium. After quenching the subsequent heat treatment is tempering with temperature variations of temperature 200<sup>o</sup>C and 300<sup>o</sup>C with a resistance time of 45 minutes and air cooling media. The results of this study showed that the base material specimens had the highest corrosion rate of 0.569 mm/y. The lowest corrosion rate is in specimens with quenching process with a value of 0.267 mm/y. The highest Vickers hardness values were found in specimens with quenching process with a value of 551 kg/mm<sup>2</sup>. The lowest hardness value is in the specimen with tempering process at 300<sup>o</sup>C with 405 kg/mm<sup>2</sup>.</p>

Study on the Heat-Treatment of Clad Plate for Cutting Tools

2013 ◽  
Vol 401-403 ◽  
pp. 916-919
Author(s):  
Lin Lin Yuan ◽  
Jing Tao Han ◽  
Jing Liu
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Cutting Tools ◽  
High Hardness ◽  
Core Layer ◽  
Water Cooling ◽  
Treatment Processes ◽  
Uniform Microstructure ◽  
Hot Rolled ◽  
Cutting Tool Materials

High sharpness, abrasion resistance, superior ductility, and processability are required in cutting tool materials application. Used 304(0Cr18Ni9) austenitic stainless steel as cladding and 440(7Cr17) martensitic stainless steel as core layer to produce excellently combined stainless steel plate by hot-rolled bonding in this investigation as well as researched various heat treatment processes. The results indicated that the core layer has high hardness and the cladding layer has tiny and uniform microstructure by the method of heating at 10501070°C for 15 minutes, water-cooling , then tempering at 200°C.

scholarly journals Pengaruh Perlakuan Temperatur dan Media Pendinginan Terhadap Sifat Ketangguhan Baja AISI 3215

Jurnal METTEK ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 23
Author(s):  
I Ketut Suarsana ◽  
IGN Nitya Santhiarsa ◽  
DNK Putra Negara
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Temperature Effect ◽  
Internal Stress ◽  
Treatment Temperature ◽  
Metal Heating ◽  
Quenching Medium ◽  
Quenching Media ◽  
Cooling Medium ◽  
Cooling Media

Perlakuan panas adalah pemanasan yang diikuti dengan penahanan dan pendinginan menggunakan media quenching. Pengerasan adalah pemanasan logam hingga suhu austenit, tahan pada suhu tersebut untuk sementara waktu dan kemudian didinginkan pada media pendinginan seperti air, minyak, udara, air garam. Untuk mengatasi perubahan sifat mekanik, perlu diberikan proses perlakuan panas. Hal ini perlu dilakukan untuk menghilangkan stress internal dan mencegah terjadinya retak atau cacat. Sifat mekanis ketangguhan adalah kemampuan material untuk menyerap energi sesaat sebelum terjadi fraktur pada struktur itu. Penelitian ini membahas tentang prediksi ketangguhan properti mekanik dengan memberikan pemanasan pada temperatur 800, 850 dan 9000C dan masing-masing specimen  diquenching dengan : air tawar, air laut dan minyak. Hasil penelitian menunjukkan bahwa terjadi peningkatan sifat ketangguhan dari efek temperatur dan media pendinginan yang digunakan. Data menunjukan pada 8000C dengan media quenching minyak nilai ketangguhan adalah 33,833 kg/cm2, serta suhu 9000C dengan quenching media air nilai ketangguhan adalah 40,8747 kg/cm2). Jadi semakin meningkat temperature perlakuan,  berpengaruh terhadap sifat ketangguhan impak bahan. Heat treatment is carried out by heating followed by anchoring and using quenching medium as cooling. Hardening is metal heating to austenite temperature, hold it at a temporary temperature and then cooled to cooling media such as water, oil, air, brine. To overcome the change of mechanical properties, need to be given process of heat treatment. This is to remove internal stress and prevent the occurrence of cracks or defects. The mechanical properties of toughness are the ability of the material to absorb energy without fracturing the structure. This study discusses the prediction of toughness of mechanical properties by heating at temperatures of 800, 850 and 9000C and each specimen quenching with: freshwater, seawater and oil. The results showed that there was an increase in the toughness properties of the temperature effect and the cooling medium used. The data show on 8000C with medium quenching oil the toughness value is 33.833 kg/cm2, and the temperature of 9000C with quenching medium water toughness value is 40.8747 kg/cm2). So the increasing of treatment temperature has influence to the material toughness

scholarly journals Analisis Kekerasan Hasil Pengelasan Gas Tungsten Arc Welding pada Baja ST 37 dengan Variasi Media Pendingin

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Gede Agus Widiantara ◽  
I Nyoman Pasek Nugraha ◽  
Kadek Rihendra Dantes
Keyword(s):  
Base Metal ◽  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Water Cooling ◽  
Gas Tungsten Arc ◽  
A Value ◽  
Gas Tungsten ◽  
Cooling Media ◽  
Weld Area ◽  
Hardness Values

Cooling media is a substance that increases the hardness value of a materialthrough a heat-treatment process. This study aims to determine the effect of cooling media on the hardness of ST 37 steel due to Gas Tungsten Arc Welding (GTAW). The method used is an experimental method using the independent variables, namely water cooling media, seawater cooling media, and oil cooling media, while the dependent variable is the hardness test result. In specimens using water cooling media, the hardness in the weld area is 47.19 kg/mm2, in the HAZ area the it is 54.6 kg/mm2, and the base metal gets a value of 40.87 kg/mm2. While the specimens with seawater cooling media get a value in the weld area of 76.37 kg/mm2, in the HAZ area it gets a value of 83.89 kg/mm2 and the base metal gets a value of 70.13 kg/mm2. The specimens with oil cooling media the value in the weld area is 40.77 kg/mm2, in the HAZ area it gets a value of 43.32 kg/mm2 and the base metal gets a value of 36.09 kg/mm2 . From the hardness values obtained, specimens immersed in seawater cooling media have the highest hardness values compared to water and oil cooling media.

Preparation of a shortened version of the Mathematics Anxiety Rating Scale-Adolescents (MARS-A)

1993 ◽  
Vol 3 ◽  
pp. 80-82
Author(s):  
Judy Sherrington
Keyword(s):  
Extracurricular Activities ◽  
Mathematics Anxiety ◽  
Curriculum Change ◽  
Rating Scale ◽  
Counseling Program ◽  
Parental Characteristics ◽  
A Value ◽  
Before And After ◽  
The Impact

The measure of mathematics anxiety most widely used in screening and as a before and after measure to evaluate the impact of interventions is the Mathematics Anxiety Rating Scale (MARS) devised by Suinn, Edie, Nicoletti, and Spinelli (1972). Alexander and Cobb (1987), Hunsley (1987), Richardson and Suinn (1972), Trent and Fournet (1987), Hadfield and Maddux (1988), Ferguson (1986), and Dew, Galassi and Galassi (1984), have used it; Wigfield and Meece (1988) refer to it as the most frequently used measure of mathematics anxiety; and Englehard (1990) recommends its use by future researchers. It was given qualified approval in a review by Hannafin (1985), and though Knapp's review (1985) was rather negative, he does concede that it has little or no competition.Suinn and Edwards (1982) produced a version of the scale for adolescents (MARS-A). As noted by Hannafin (1985), it is virtually indistinguishable from the original, the differences involving minor and infrequent word substitutions.According to Suinn (1979, p.2):The MARS-A can be used to screen individual students in order to plan their placements in special mathematics courses, provide counseling, or provide for intervention through programs such as desensitization for anxiety. Typically, a value above the 75% level would indicate the student is eligible for attention of this type, however a school may wish to develop its own norms or cut-off scores.The MARS-A can also be used as a measure for evaluating programs. It could be administered prior to a new counseling program or curriculum change, and readministered later to determine the effects of the program. Finally, the MARS-A may be used as a part of direct research on mathematics anxiety. For example, it would be a useful measure in studies which examine the role of curriculum content, parental characteristics, extracurricular activities, etc., influencing mathematics anxiety.

Unnecessary wait hours: a novel ED system-level metric

2020 ◽  
Vol 37 (9) ◽  
pp. 552-554
Author(s):  
Heather A Heaton ◽  
David M Nestler ◽  
Kalyan S Pasupathy ◽  
Phichet Wutthisirisart ◽  
Mustafa Y Sir ◽  
...  
Keyword(s):  
Opposite Effect ◽  
Care Delivery ◽  
System Level ◽  
Space Efficiency ◽  
A Value ◽  
Number Of Patients ◽  
Before And After ◽  
Ed Operations ◽  
The Relationship

BackgroundEmergency department (ED) operations leaders are under increasing pressure to make care delivery more efficient. Publicly reported ED efficiency metrics are traditionally patient centred and do not show situational or facility-based improvement opportunities. We propose the consideration of a novel metric, the ‘Number of Unnecessary Waits (NUW)’ and the corresponding ‘Unnecessary Wait Hours (UWH)’, to measure space efficiency, and we describe how we used NUW to evaluate operational changes in our ED.MethodsUWH summarises the relationship between the number of available rooms and the number of patients waiting by returning a value equal to the number of unnecessary patient waits. We used this metric to evaluate reassigning a clinical technician assistant (CTA) to the new role of flow CTA.ResultsWe retrospectively analysed 3.5 months of data from before and after creation of the flow CTA. NUW metric analysis suggested that the flow CTA decreased the amount of unnecessary wait hours, while higher patient volumes had the opposite effect.ConclusionsSituational system-level metrics may provide a new dimension to evaluating ED operational efficiencies. Studies focussed on system-level metrics to evaluate an ED practice are needed to understand the role these metrics play in evaluation of a department’s operations.

scholarly journals Effect of Cooling Media on Steel Hardness ST 37 of Conventional Lathe Process

2018 ◽  
Author(s):  
Teknomekanik ◽  
Nelvi Erizon ◽  
M. Iksan Ardiyansyah ◽  
Jasman ◽  
Yufrizal. A
Keyword(s):  
Oil Content ◽  
Hardness Test ◽  
Air Cooling ◽  
Hardness Tester ◽  
Cooling Medium ◽  
Average Hardness ◽  
Spindle Rotation ◽  
Boring Tool ◽  
Cooling Media ◽  
Hardness Values

This study aims to determine the type of air cooling media, soluble oil, and air to the result on lathe ST 37 steel. The cooling medium is very important to maintain boring tool deformation and can add product quality. In the process lathe of friction between the workpiece and chisel cut that can produce overheating and influence on the result of the slice boring tool on the workpiece. The research that will be carried out is experimental research with variables that are controlled that is feeding, deep of a cut, and spindle rotation and examination of the hardness of the specimen on the object before done lathe. The sample in this study which is ST 37 steel with diameter 25 mm and length 60 mm as many as 9 specimens which will be done lathe with different type media kind inprocess working. To know influence the type of cooling medium against steel ST 37 is done brinnel hardeness test using test equipment hardness tester. Of the 9 specimens lathe will be determined 3 points to do hardeness tests. From the result of hardness test and analysis obtained from hardness test on steel ST 37 average data that is use of soluble refrigerant media that produce a very good cooling at the time of the lathe process. The results of research is obtained that the use of soluble refrigerant media is the best with an average hardness of 224.10 kg / mm². On the lathe process, the cooling media has oil content will be able to maintain the scores hardness and time-worn on boring tool. Thus to maintain the hardness values can be used soluble oil cooling media and to increase the hardness values of workpieces can be used air cooling media.

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