Behavior of Carbon Steel Machine Elements in Acidic Environment Surface Texture Using Abbott Firestone Curve

The objective of this paper is to study the surface texture behavior of low and medium-carbon steels machine elements in acidic environment using Abbott Firestone curve depending upon MATLAB software. The chemical composition of low-carbon steel is 0.16C-0.27Si-1.47Mn-0.02Al while medium-carbon steel is 0.49C-0.30Si-0.91Mn-0.03Al. They were hot-rolled at 1200 degrees C for 30 min followed by air cooling. Two different heat treatment processes were applied on the hot-rolled samples. The first treatment was quenching after martensite finish (QAM(f)) and the second one was quenching and partitioning (Q&P). For 0.16C, the microstructure gives bands of ferrite and pearlite after hot-rolled steel. However, 0.49C produces coarse pearlite islands surrounded by ferrite phase. While, the microstructure after QAM(f) and Q&P processes contain ferrite, bainite, lath martensite, and retained austenite for 0.16C steel, and polygonal ferrite, lath martensite, and retained austenite for 0.49C steel, respectively. In low-carbon steel (0.16C), after hot-rolling, steel suffers from low exploitation zone (44%) of surface texture. However, after QAM(f), low-carbon steel (0.16C) gives lower surface texture (36%). In addition, hot-rolled steel (0.16C) produces 40% voids zone while after QAM(f,) voids zone increases to 52% of surface texture. In medium-carbon steel (0.49C), after hot-rolling, steel produces 78% exploitation zone of surface texture. Furthermore, Q&P slightly enhances surface texture (exploitation zone) to 82%. At the same time, hot-rolled and Q&P of 0.49C steels exhibit very small number of voids for surface texture (1-4%). Therefore, 0.16C steel (hot-rolled and QAM(f)) is highly subjected to severe failure in etchy environment. However, 0.49C steel (hot-rolled and Q&P) is highly recommended in case of moderate safety factor.