scholarly journals Case Depth Prediction of Nitrided Samples with Barkhausen Noise Measurement

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 325 ◽  
Author(s):  
Aki Sorsa ◽  
Suvi Santa-aho ◽  
Christopher Aylott ◽  
Brian Shaw ◽  
Minnamari Vippola ◽  
...  

Nitriding is a heat treatment process that is commonly used to enhance the surface properties of ferrous components. Traditional quality control uses sacrificial pieces that are destructively evaluated. However, efficient production requires quality control where the case depths produced are non-destructively evaluated. In this study, four different low alloy steel materials were studied. Nitriding times for the samples were varied to produce varying case depths. Traditional Barkhausen noise and Barkhausen noise sweep measurements were carried out for non-destructive case depth evaluation. A prediction model between traditional Barkhausen noise measurements and diffusion layer hardness was identified. The diffusion layer hardness was predicted and sweep measurement data was used to predict case depths. Modelling was carried out for non-ground and ground samples with good results.

2020 ◽  
Vol 856 ◽  
pp. 294-302
Author(s):  
Porawon Nitjarunkul ◽  
Sai Yan Primee ◽  
Komkamol Chongbunwatana ◽  
Nopparat Seemuang

Barkhausen noise (BHN) measurement is one of electromagnetic testing methods that is suitable for ferromagnetic materials. It has a sensitivity to different material properties such as microstructure, composition, residue stress, hardness, etc. which can also be used to determine the hardness case depth of a hardened layer. The measurement is intriguing because of its time and cost-effectiveness. The aim of this work was to study and select a suitable method to evaluate and predict the hardness case depth of induction hardened S50C steel based on Barkhausen noise measurement. Signal processing of BHN signal was performed and extracted features were validated with the actual hardness case depth according to the destructive method of Vickers hardness and metallography in order to achieve the most accurate hardness case depth evaluation model. The results showed that the hardness case depth prediction model could be used to indicate the hardness case depth of induction hardened steel significantly at the correlation coefficient (R) of 0.97 and root mean squares error of estimation (RMSEE) of 3.56%.


2003 ◽  
Vol 1 (1) ◽  
pp. 3-35 ◽  
Author(s):  
Judy Sterner ◽  
Nicholas David

The publication, largely by ethnoarchaeologists, of new data on the tamper and concave anvil technique of pot-forming (TCA) permits a reassessment of this uniquely African technique, its toolkit, and its culture history. A survey, inspired by the technologie culturelle school, of its varied expressions in the southern Saharan, Sahelian and northern Sudan zones from Mali to Sudan and extending north into Egypt emphasises the potential of the technique for the efficient production of spherical water jars of high volume to weight ratio, much appreciated in arid environments. The technique is demanding and therefore practised for the most part by specialists. The origins and diffusion of the technique are assessed in the light of the ethnological, archaeological, linguistic, and historical evidence, and a four stage historical development is sketched.


2021 ◽  
Vol 11 (10) ◽  
pp. 4586
Author(s):  
Ana Silveira ◽  
João Cardoso ◽  
Maria José Correia ◽  
Graça Martinho

Moisture content is a quality issue raised by recycling plants in the acceptance of paper and cardboard coming from waste streams. The current way to measure this parameter is by the oven drying method, which is a slow and invasive process, costing time and resources for the recyclers to do this type of quality control. An alternative to such a measurement technique is the use of plate-form devices which indirectly measure the moisture content using the dielectric properties of water and paper. This study has tested this method and developed a representative equation for the use of devices with these properties in the Portuguese market. For that, 48 wastepaper and cardboard bales were tested with both the traditional (oven drying) method and a commercial device equipped with dielectric technology. An equation that fits the studied reality (R2 = 0.76) was achieved, and possible problems regarding the use of this device were tested. The results showed that this type of device could be used as a time- and cost-saving, non-destructive and reliable method in the quality control of wastepaper and cardboard bales.


2016 ◽  
Vol 90 ◽  
pp. 85-95 ◽  
Author(s):  
Marten Klukkert ◽  
Jian X. Wu ◽  
Jukka Rantanen ◽  
Jens M. Carstensen ◽  
Thomas Rades ◽  
...  

2021 ◽  
Vol 263 (3) ◽  
pp. 3436-3447
Author(s):  
Dan Lin ◽  
Andrew Eng

Assumptions made on the ground types between sound sources and receivers can significantly impact the accuracy of environmental outdoor noise prediction. A guideline is provided in ISO 9613-2 and the value of ground factor ranges from 0 to 1, depending on the coverage of porous ground. For example, a ground absorption factor of 1 is suggested for grass ground covers. However, it is unclear if the suggested values are validated. The purpose of this study is to determine the sound absorption of different types of ground by measurements. Field noise measurements were made using an omnidirectional loudspeaker and two microphones on three different types of ground in a quiet neighborhood. One microphone was located 3ft from the loudspeaker to record near field sound levels in 1/3 and 1 octave bands every second. The other microphone was located a few hundred feet away to record far field sound in the same fashion as the near field microphone. The types of ground tested were concrete, grass, and grass with trees. Based on the measurement data, it was found that grass and trees absorb high frequency sound well and a ground factor of 1 may be used for 500Hz and up when using ISO 9613-2 methodology. However, at lower frequencies (125 Hz octave band and below), grassy ground reflects sound the same as concrete surfaces. Trees absorb more low frequency sound than grass, but less than ISO 9613-2 suggested.


2016 ◽  
Vol 827 ◽  
pp. 113-116 ◽  
Author(s):  
Kamil Kolařík ◽  
Nikolaj Ganev ◽  
Karel Trojan ◽  
Ondřej Řídký ◽  
Lukáš Zuzánek ◽  
...  

Non-destructive methods for detection and measurement of residual stresses (RS) have been increasingly used in the last few years. The paper outlines the capability of Barkhausen noise analysis (BNA) for evaluation of real structure changes and RS on cross-section of welds due to welding of ferromagnetic plates compared with X-ray diffraction (XRD). The purpose of this study is to evaluate the RS distribution of specimens joined using by high power diode laser and metal active gas (MAG) welding that can be used for quantitative analysis of macro and micro level RS separately. The principal advantages of BNA over XRD as a tool for RS analysis and real structure characterisation are that it is mobile, faster with more facile carrying out and hence BNA is frequently used for continuous monitoring of RS in industrial processes.


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