KARAKTERISTIK ENGINE MOUNTING PADA TEMPERATUR AUSTENISASI TERHADAP SIFAT MEKANIS DAN STRUKTUR MIKRO

Engine mounting is one of the car component which is has optimize function to obtain thesystem in the car is extremely perfect. The engine mounting has to be have behavior ductile by strongestenough to support the car engine whether in rest and moving position. To obtain car engine mountingwhich has these function it has to be treated by treatment. The method was used by using Heat TreatmentSystem which we were Hardening and Tempering. Heat treatment of engine mounting is needed toanalyze the microstructure and mechanical properties of low carbon steel used. Tests carried out attemperatures of 800oC, 850oC, 900oC and normal conditions without heat treatment. Then continued withimpact charpy testing, vickers hardness testing, microstructure observation using microscope and SEM.The tests are carried out in accordance with ASTM E23, ASTM E92, ASTM A370 standards. The Vickerstest results provide the lowest HV value of 118.7Hv at 900oC, while the normal condition is at 137.409Hv.The charpy impact test results give the lowest value of 0.06 j / mm2 under normal conditions, while at900oC at 0.0962 j / mm2. The results with microscopy and SEM, the greater the temperature given to heattreatment, the less pearlite will be, while the amount of ferrite and austenite increases which makes theengine mounting more toughness.

Influence of High Temperature Annealing on Microstructure Evolution of Ni-24Fe-14Cr-8Mo Superalloy

The effect of high temperature annealing on microstructure evolution of Ni-24Fe-14Cr-8Mo alloy was investigated through Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Rockwell Hardness Testing Machine. Three kinds of grain growth patterns were found at different annealing temperatures due to carbides precipitation and dissolution. After a combination of high temperature annealing and aging treatment, the hardness versus time curves performed a parabolic pattern. The highest hardness was achieved under 1070°C/60 minutes treatment, and the desirable annealing time should be 60 minutes to 90 minutes.

Analisis Struktur Mikro dan Kekerasan Paduan Aluminium ADC 12 Hasil Proses Pengecoran Semi Solid dengan Proses Perlakuan Panas

This research aims to analyze the effect of providing additional heat treatment and artificial aging with variations in temperature of quenching and variations in aging time of ADC12 semi-solid casting result which include hardness and microstructure values. The Selected quenching temperature variations are 10°C, 30°C and 50°C. While the aging time variations are 0 h, 1 h, 3 h, 5 h, 7 h, 9 h, 11 h and 13 h. The tests carried out are hardness testing as well as microstructure that will be used to calculate the grain size values and structural density. The highest hardness value was at 180°C, 10°C cooling media variation with 5 h aging time is 83.10 HB. While the smallest grain size value was at the temperature of 10°C cooling media with an aging time of 5 h is 42.797 µm. The optimal value lies at a temperature of 10°C with an aging time of 5 h resulting hardness 83.7911 HB, the average of grain size is 13.5995 µm and the grain density value is 0.8892 with desirability reaching 0.920.

Analisis Struktur Mikro dan Kekerasan Paduan Aluminium ADC 12 Hasil Proses Pengecoran Semi Solid dengan Proses Perlakuan Panas

This research aims to analyze the effect of providing additional heat treatment and artificial aging with variations in temperature of quenching and variations in aging time of ADC12 semi-solid casting result which include hardness and microstructure values. The Selected quenching temperature variations are 10°C, 30°C and 50°C. While the aging time variations are 0 h, 1 h, 3 h, 5 h, 7 h, 9 h, 11 h and 13 h. The tests carried out are hardness testing as well as microstructure that will be used to calculate the grain size values and structural density. The highest hardness value was at 180°C, 10°C cooling media variation with 5 h aging time is 83.10 HB. While the smallest grain size value was at the temperature of 10°C cooling media with an aging time of 5 h is 42.797 µm. The optimal value lies at a temperature of 10°C with an aging time of 5 h resulting hardness 83.7911 HB, the average of grain size is 13.5995 µm and the grain density value is 0.8892 with desirability reaching 0.920.

A Novel coarse-to-fine Localization Algorithm for Automated Vickers Hardness Measurement

Vickers hardness testing is one of the most useful methods to determine the hardness of materials. To calculate the hardness of materials, the key is to measure the diagonal length of the Vickers indentation on the surface accurately. However, since this length is extremely minuscule, there are many challenges to achieve accurate measurement. Especially, when the indentation corner is cracked, the precise position of the corner cannot be obtained by conventional methods. In this paper, we proposed a method of coarse-to-fine localization to accurately locate the indentation corner. The coarse localization process can be used to determine the position and size of the indentation. During fine localization, the linear equations of the indentation edges are calculated by the line fitting method. The capabilities of the proposed method are compared to manual measurement and results are presented.

Magnetic Methods for the Identification of Incorrect Microstructures in Grade 91 Power Station Steels

Grade 91 steels have been used in power generation for more than 20 years in high temperature, high pressure applications such as steam piping, headers and tubing because it provides superior creep and oxidation resistance at elevated temperatures. The mechanical properties of the material are dependent on the creation of a martensitic microstructure, however incorrect heat treatment during manufacture, installation or repair can result in a weak ferritic or semi-ferritic microstructure which can cause premature component failure. Currently, components with incorrect, weak microstructures are identified using hardness testing; a manual technique which is prone to error. This work details a series of tests carried out at the University of Manchester to assess the suitability of multi-parameter magnetic testing for the identification of incorrect microstructures. The tests stem from a workshop organized by the Electric Power Research Institute (EPRI) where three sets of samples (eight pipe sections, eight tube sections and eight unidentified tube sections) with different microstructures were circulated world-wide. The results of the work show that the magnetic measurement techniques employed in these tests have the potential to provide a basis for the development of a portable NDE system for the identification of incorrect microstructures in Grade 91 plant components. The developed system would enable fast scanning of components with very little surface preparation along with digital data storage, improving on current manual hardness testing.