Optimization of Processing Parameters for Minimum Residual Stress and Maximum Wear Resistance During Gas Nitration of 4140 Steel

Year 2022, Volume: 25 Issue: 2, 909 - 920, 01.06.2022

Sibel Tüzüner , Ali Baran Metin , Ebru Saraloğlu Güler , Tuğçe Şahin

https://doi.org/10.2339/politeknik.993934

Cited By: 1

Abstract

Several surface treatments has been applied to the 4140 specimens which are exposed to frictional conditions like gears in order to increase the wear resistance and hardness. Nitration is a common method to improve the hardness of the surfaces. However, the parameters must be chosen wisely. The parameters of temperature, time, flow rate during nitration of SAE 4140 steels were optimized in this study. The ranges for the parameters are selected as 470⁰C - 520⁰C - 570⁰C, 7h - 9h - 12h and 6m3/h - 7.5m3/h - 9m3/h for temperature, time and flow rate respectively. Residual stress, hardness and wear resistance were measured for the specific experiments together with microscopic observations. The nitration process of the threaded part was completed using the optimized parameters.
As a result of the study, it was observed that the maximum wear resistance and minimum residual stress values was obtained by the parameters of 470⁰C, 12h, 9m3/h.

Keywords

Gas Nitration, SAE 4140 steel, wear resistance, residual stress, microhardness

Supporting Institution

TÜBİTAK & HİDROMEK A.Ş.

Project Number

1139B412001125

Thanks

We would like to thank HIDROMEK for their support in the realization of this study, and TUBITAK BIDEB for their support within the scope of TUBITAK 2209-B Industry-Oriented Undergraduate Research Projects Support Program.

Gaz Nitrasyon Yapılan 4140 Çeliğinin Minimum Kalıntı Gerilim ve Maksimum Aşınma Dayanımı İçin İşlem Parametrelerinin Optimizasyonu

Abstract

Dişliler gibi sürtünme koşullarına maruz kalan 4140 çeliği numunesinin aşınma direncini ve sertliğini arttırmak için çeşitli yüzey işlemleri uygulanmıştır. Nitrasyon, yüzeylerin sertliğini iyileştirmek için yaygın bir yöntemdir. Ancak, parametreler dikkatli bir şekilde seçilmelidir. Bu çalışmada SAE 4140 çeliklerinin nitrasyonu sırasında sıcaklık, zaman, debi parametreleri optimize edilmiştir. Parametre aralıkları sıcaklık, zaman ve debi için sırasıyla 470⁰C - 520⁰C - 570⁰C, 7sa – 9sa – 12sa and 6m3/sa - 7.5m3/sa - 9m3/sa olarak seçilmiştir. Mikroskobik gözlemlerle birlikte spesifik deneyler için kalıntı gerilim, sertlik ve aşınma direnci ölçülmüştür. Optimize edilmiş parametreler kullanılarak dişli parçanın nitrasyon işlemi tamamlanmıştır.
Çalışma sonucunda maksimum aşınma direnci ve minimum kalıntı gerilim değerlerinin 470⁰C, 12sa, 9m3/sa parametreleri ile elde edildiği gözlemlenmiştir.

Keywords

Gaz Nitrasyon, SAE 4140 çeliği, aşınma dayanımı, kalıntı gerilim, mikrosertlik

Project Number

1139B412001125

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