A Study of the Effect of Average Preset Voltage on Effective Case Depth During Electrolytic Surface-Hardening

1999 ◽  
Vol 42 (2-3) ◽  
pp. 65-71 ◽  
Author(s):  
S.F Luk ◽  
T.P Leung ◽  
W.S Miu ◽  
I Pashby
2015 ◽  
Vol 776 ◽  
pp. 201-207 ◽  
Author(s):  
Dewa Ngakan Ketut Putra Negara ◽  
I. Dewa Made Krisnha Muku ◽  
I. Ketut Gede Sugita ◽  
I. Made Astika ◽  
I. Wayan Mustika ◽  
...  

This research is concerned with the effect of different carburizers on hardness distribution, effective case depth and microstructure of low carbon steel after pack carburizing process. Carburizers to be used were combination of energizer (BaCO3), goat bone charcoal and bamboo charcoal with five different compositions. The specimens were heated to temperature of 950°C, soaked at the temperature for 4 hours and quenched in the water. After the process, microstructures of specimen were observed, the hardness was measured using Vikers method and effective case depths were calculated. The results obtained showed that for all types of carburizer used, the hardness were scattered from surface to the core with lower hardness level. Carburizer composition of 20% BaCO3 + 80% goat bone charcoal produced the highest hardness ( 789.273 HV1) at 0.2 mm from the surface, however, it yielded the lowest effective case depth (0.52 mm). The highest effective case depth of 1 mm was obtained using carburizer composition of 20% BaCO3 + 60% goat bone charcoal + 20% bamboo charcoal. Meanwhile, the original structures of raw material which consist of ferrite and pearlite transformed to hard martensite constituent in the surface after pack carburizing.


2021 ◽  
Vol 349 ◽  
pp. 02006
Author(s):  
Arsenis Dragatsis ◽  
Leonidas Fragkos-Livanios ◽  
Dimitris G. Papageorgiou ◽  
Carmen Medrea

DIN 15CrNi6 is the most representative grade of the case-hardened steels. The present work analyses the influence of carburizing time on hardness of the specific steel. Specimens with similar chemical composition were heated at 900°C in liquid carbonaceous media for one, two, three and four hours, correspondingly. Then samples were oil quenched and tempered at 180°C for two hours. Microhardness was measured across the carburized zone and case profiles were acquired. The effective case depth was determined as function of carburizing holding time. Core macro hardness was carried out and the impact of holding time on the substrate hardness was discussed. The optimum case depth was defined and the carburizing parameters determined. The hardness control is critical in case hardening practice and results provide practical information to heat treaters, useful both to control the treatment parameters and to minimize the risk of failure.


2019 ◽  
Vol 395 ◽  
pp. 124-132
Author(s):  
Atsushi Nakamura ◽  
Koichiro Nambu ◽  
Masahiro Okumiya

N-Quench, which is a new surface heat treatment to infiltrate nitrogen into steel parts followed by quenching to achieve hardening, is gathering attention in the nitriding field as it affords low distortion while maintaining a higher effective case depth (ECD) compared with conventional nitriding. N-Quench is conducted mainly between 680°C and 800°C, where the two-phase region of ferrite and austenite exists in the Fe-N phase diagram. However, a few studies have reported on nitriding at temperatures higher than 800°C due to decomposition of NH3, which is a key source of nitrogen infiltration. Our results revealed that in a conventional furnace such as resistance heating furnace, no nitrogen infiltrated the specimen at 930°C, which is the general carburizing temperature. On the other hand, in the infrared heating furnace, nitrogen infiltrated the specimen at 930°C successfully with lesser NH3 introduction than that required by the conventional furnace. Therefore, in this study, the limit of NH3 decomposition is assessed and possibility of extending the applicability of N-Quench, especially increasing the ECD while maintaining a low distortion, is examined.


DENKI-SEIKO ◽  
1991 ◽  
Vol 62 (3) ◽  
pp. 175-182
Author(s):  
Toshio Endoh ◽  
Tomikazu Yagi ◽  
Ken-ichi Takata

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