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Go to Editorial ManagerThe present study aims to investigate the influence of heat treatment and surface finish on the behavior of crevice corrosion resistance of AISI 410 and 416 martensitic stainless steels thus, to quantify the conditions at which crevice corrosion minimize as possible. The experimental work carried out during this study involves material selection, chemical composition tests, specimens preparation before heat treatments, austenitizing at temperature range (925-1010˚C) and for holding time periods of (30, 45 and 90 min), air and oil quenching followed by tempering at heating range of (205- 605 ̊C) and for 45 min, micro hardness tests, specimens grinding, surface roughness measurements, crevice corrosion tests, crevice evaluation and microstructure tests. Theoretically, empirical equations for crevice maximum depth under the effect of surface roughness and hardness for both AISI 410 and 416 steels were determined. While for microstructure analysis, carbides average area was determined by using the ImageJ analysis program and a mathematical model was also predicted. Results showed that, as hardness and surface roughness increase crevice corrosion resistance decreases. Therefore, material treated by annealing can minimize crevice corrosion rates more than that treated with hardening.
The mechanical properties of low alloy steel are significantly influenced by retained austenite (RA). Consequently, using the X-Ray diffraction (XRD) measurement method, the retained Austenite volume fractions in AISI4330 alloy steel have been assessed in this article. The specimens underwent heat treatment at various heating temperatures (800 ֯ C, 900 ֯ C,1000 ֯ C) and cooling rates (Water and Oil). The findings demonstrate that retained Austenite formation rises with rising heating (Austenitizing) temperatures for the same quenching media as well as with rising cooling rates. The specimens were heated to a temperature of 1000 °C and then quenched in water, yielding the highest amount of retained austenite (7.733 wt%), and the lowest amount (1.977 wt%), which was obtained when the specimens were heated to a temperature of 800 °C and quenched in oil. The Vickers method was employed to conduct micro-hardness testing, and the results demonstrate that hardness values are reduced as heating temperatures increase. Optical microscopy was used to investigate the effects of retained austenite on the microstructure. The results show that bainite and/or martensite phases with a small amount of retained austenite dominate the microstructure at low cooling rates, whereas martensite and retained austenite phases dominate the microstructure at higher heating and cooling rates.
The aim of this study is to investigate the effect of heat treatments on the impact properties of hot rolled high strength steel and describes the effect of tempering temperature and quenching media on the microstructure, hardness, and impact resistance of plates. In the present study a high strength steel was austenitized at 900 °C with different quenching medium and followed by tempering at 300 °C, 500 °C. After thermal treatments, the values of Charpy impact resistance, hardness, and microscopic structure were evaluated from mechanical and metallographic analysis of metals respectively. The change of mechanical properties and microstructure of the metal with the existence of heat treatment with the ballistic performance of high-strength steel. Experimental results showed that tempering at 500 °C for 2 hours after water quenching medium it provides the best mechanical properties in conjunct on with an improved in microstructure.