RUDN University professors increased the “lifetime” of steel parts using a neural network

Repeated stress on metal parts causes “fatigue failure.” Each stress leads to microcracks that accumulate over time. Larger damage appears, and finally the part fails. Fatigue failure inevitably occurs in almost all mechanisms, this applies to all areas of industry, so technologists and scientists are looking for ways to strengthen the metal using various coatings and processing methods. RUDN University professors, together with colleagues from Italy, Canada and Turkey, built an artificial neural network that is able to predict the life of a part made of AISI 1045 steel, which makes up half of the mechanical engineering products, and select the optimal coating.

“Most machine components in the marine, oil and gas, and wind power industries are subject to repeated applied loads that cause fatigue failure. Since the phenomenon of fatigue failure is very sensitive to various parameters, including material, load, temperature, humidity, vibration, and so on, it is convenient to use neural networks for its analysis,” Reza Kashi Zadeh Kazem, professor of the Department of Transport of RUDN University.

Engineers have created a neural network that can estimate the “lifetime” of AISI 1045 carbon steel with different types of coatings under repeated loads. Nickel, hardened chrome and zinc were used as protective coatings in the model. RUDN University researchers have achieved 99% accuracy in neural network predictions. Moreover, the authors were able to select the optimal protective coating — a layer of nickel or zinc 10–15 micrometers thick. Hardened chromium has been shown to reduce the steel’s resistance to fatigue failure.

First, RUDN scientists conducted a series of experiments with real steel parts. 23% of the obtained data was used to train the neural network, and the rest was used to test the resulting predictions. The scientists tested several neural networks, with different numbers of internal layers and neurons in each layer.

“We investigated the effect of various traditional industrial coatings, including nickel, chromium and zinc, which are commonly used to improve corrosion resistance, on the fatigue life of AISI 1045 carbon steel. The experimental results showed that nickel and hot-dip galvanized coatings with a thickness of 13 microns improved fatigue life. On the contrary, hardened chromium reduces the fatigue life of AISI 1045 steel,” Igor Danilov, Doctor of Technical Sciences, Director of the Department of Transport of the RUDN University.

The results were published in the journal JMSE.