Gingot45 Steel Metallurgical Analysis
The steel sample used in thisanalysis is Gingot45, a medium-carbon steel with a high-frequency heat treated surface. On microscopic inspection, the microstructure consists of concrete grain boundary regions with features of severely deformed austenite, ferrite and pearlite (MMP), as well as supersaturated dispersed hard particles of complex silicon, carbon and other alloy components such as molybdenum (Mn), copper (Cu), chromium (Cr) and nitrogen (N). Under a magnifying glass, the sample appears to be in an annealed state, with ferrite grains around the grain boundaries.
The review of the chemical composition of Gingot45 steel reveals that it is a medium carbon alloy consisting of 0.4-0.45% carbon, 1.2-1.4% manganese, 0.1-0.1% chromium, 0.03-0.03% silicone, 0.14-0.14% molybdenum, 0.6-0.6% nickel, and 0.2-0.2% nitrogen. The chemical composition is what gives the steel its name; the combination of high carbon and low nickel yields a strength and toughness akin to a grade 45 steel.
In terms of mechanical behavior, Gingot45 demonstrates superior strength and good ductility. The mechanical properties include an ultimate tensile strength (UTS) of approximately 600 MPa, an elongation at break of 13%, a modulus of elasticity of about 200 GPa, and a hardness of around 27 HRC. The results show why it is suitable for applications in which a combination of high strength and ductility is required.
The behavior of Gingot45 under heat treatment reveals it to be quite amenable to forming processes. The alloys metallurgical response to cold working is primarily controlled by the volume fraction of soft ferrite, the fraction of pearlite, and the fraction of hard, super-saturated particles. Its response to heat treatment is practically the same, although it appears to be slightly more sensitive to temperature changes. Once heated, the alloy recovers its full strength, with minimal deformations and an acceptable degree of hardness, allowing it to be formed with relative ease.
Finally, the results of a metallographic analysis reveal that the Gingot45 microstructure is composed of fine-grained, low-carbon ferrite grains with higher carbon pearlite bands and hardened particles, which appear at a rate of 4-5% in the ferrite matrix. Additionally, there is evidence of cold-working, where the fine ferrite grain boundaries have been stressed from cold working and retain oxide inclusions, resulting in a higher-than-normal hardness and strength.
Overall, Gingot45 steel exhibits superior strength and good ductility and appears to be quite amenable to forming processes. The chemical composition and microstructure of the steel work in tandem, yielding a strong and tough alloy, ideal for uses that require a combination of high strength and ductility. Furthermore, the presence of hard, super-saturated particles and the alliance between the ferrite, pearlite and cold working lend the alloy an enhanced level of hardness and strength, making it suitable for a number of applications.
