Effect of heat treatment and cryogenics on hardness of ductile cast iron microstructure (FCD­50)

The results of researches of possibilities of increasing the mechanical properties of pig iron with ball-bearing graphite of brand FCD-50 by the combined heat treatment are described. The scheme of multistage heat treatment, the characteristic feature of which is the operation of cooling in liquid nitrogen, is proposed. The use of such a scheme allows for increased HRC hardness characteristics. The study of the microstructure of cast iron treated with this scheme has proved the efficiency of the cryogenic heat treatment stage and determined its rational regimes.To match or approximate the properties of steel, the mechanical properties of this ductile cast iron 50 (FCD-‎‎50) must be ‎enhanced by methods such as ACTDI (austemper cryogenic and temper Ductile Iron). In this procedure, the FCD-50 specimen is inserted into the electric kitchen heater at 350 °C ‎‎(room temperature), heated to 600 °C and held at this temperature for 45 minutes. Next, the ‎specimen is heated to 900 °C and held at this temperature for 1 hour ‎‎(temperature austenisation). Then, the specimen is placed in furnace 2 at 3,000 °C for 45 minutes ‎‎(austempering process). The specimen subsequently is cooled in ‎liquid nitrogen. In this study, additional specimens were obtained for hardness and ‎microstructure tests. The as-cast test yielded a ‎hardness value of 18.39 HRC. In the hardness test for the ACTDI process, 12 ‎hours of submersion yielded the highest hardness result of 24.25 HRC. ‎In terms of the changes in microstructure after soaking changes, the amount of perlite present in the specimen was greater than that of ferrite, and the arrangement of graphite ‎nodules was better than that of the as-cast material.‎Описаны результаты исследований возможностей повышения механических свойств чугунов с шаровидним графитом марки FCD-50 путем комбинированной термической обработки. Предложена схема многоступенчатой термической обработки, характерной особенностью которой является операция охлаждения в жидком азоте. Использование такой схемы позволяет получить повышенные характеристики твердости HRC. Исследованием микроструктуры чугунов, обработанных по такой схеме, доказана эффективность криогенного этапа термической обработки и определены ее рациональные режимыОписано результати досліджень можливостей підвищення механічних властивостей чавунів з шаровідним графітом марки FCD-50 шляхом комбінованої термічної обробки. Запропоновано схему багатоступінчастої термічної обробки, характерною особливістю якої є операція охолодження у рідкому азоті. Використання такої схеми дозволяє отримати підвищені характеристики твердості HRC. Дослідженням мікроструктури чавунів, оброблених за такою схемою, доведена ефективність кріогенного етапу термічної обробки та визначено її раціональні режим

Pengaruh Gaya Kepemimpinan Dan Budaya Organisasi Terhadap Kinerja Karyawan Pada Kantor Kecamatan Panggungrejo Kabupaten Blitar

The purpose of this study is to analyze whether the variables of leadership style and organizational culture affect the performance of employees at the Panggungrejo District Office in Blitar Regency simultaneously or partially, as well as analyzing the most dominant variables among the leadership styles and organizational culture. The population in this study were all employees in the District Office of Panggungrejo, Blitar Regency, amounting to 31 (thirty one) people. In this study, because the population is relatively small and relatively easy to reach, the authors use the total sampling method by using all employees in the population. The analytical method used in this research is multiple linear regression analysis. The results showed that the leadership style and organizational culture together had an influence on the performance of employees at the Panggungrejo District Office in Blitar Regency. Leadership style does not have an influence on employee performance at the Panggungrejo District Office in Blitar Regency. Organizational culture has no influence on employee performance at the Panggungrejo District Office in Blitar Regency. Organizational culture is the most dominant variable in this study