Enhancing Corrosion Resistance and Hardness Properties of Carbon Steel through Modification of Microstructure

Abstract

Steel has played a primary role as structural and fabricating materials in various industrial applications—including the construction sector. One of the most important properties of steel that required a constant improvement is corrosion resistance specifically in corrosive environment. For this purpose, various approaches have been conducted through different heat treatment parameters to compare its microstructural engineering on chemical and mechanical properties. In this paper, correlation of different microstructure on corrosion resistance and hardness properties have been investigated. Three different heat treatment cycle have been applied on carbon steel with same composition to prepare dual-structure (DS) steel that consisted of ferrite/pearlite and triple-structure (TS) with ferrite/pearlite/bainite and ferrite/bainite/martensite. Phase transformation during heat treatment process was analyzed through in-situ ultra-high temperature confocal microscopy. Effect of corrosion behavior on these steels was investigated by Tafel plot, Scanning Electron Microscopy (SEM), 3D laser scanning confocal microscopy (3DLSCM), and calculation of phase volume fraction by ImageJ. Mechanical test was conducted by Vickers hardness test. It has been found that TS steels that have improvement in corrosion resistance accounted around 5.31% and hardness value for up to 27.34% more than DS steel, because of tertiary phase—bainite/martensite. This corrosion rate was reduced due to decreased numbers of pit growth and lower level of boundary corrosion as bainite/martensite phases emerged.

Enhancing Corrosion Resistance of High-Carbon Steel by Formation of Surface Layers Using Wastes as Input

“…With relatively smaller grain size of both phases on HCS-B and HCS-D on interface region, it has higher potential risk of corrosion attack than HCS-C. This aspect was due to higher boundary-to-boundary contact and the difference in potential energy between phases, thus, prone to boundary and pitting corrosion [14,15]. The other aspect was because of martensite has higher carbon (C) content than retained austenite that possessed higher iron (Fe) content, resulting martensitic phase acted as cathode, whereas the austenitic phase referred as anode, hence preferential attack on retained austenite [14,15].…”

“…This aspect was due to higher boundary-to-boundary contact and the difference in potential energy between phases, thus, prone to boundary and pitting corrosion [14,15]. The other aspect was because of martensite has higher carbon (C) content than retained austenite that possessed higher iron (Fe) content, resulting martensitic phase acted as cathode, whereas the austenitic phase referred as anode, hence preferential attack on retained austenite [14,15]. As results, bulk properties remained unmodified with layers being formed in three waste-treated samples through the reduction process of the wastes [16] into substrate of the steel.…”

Comparison on corrosion performance of waste-based multi-hybrid structure high carbon steel and high Cr cast steel

“…On the other hand, sample-B performed higher i corr value and more negative E corr value than multi-hybrid layer steel, meaning that waste-integrated inputs as source for production of multi-hybrid layer steels has corrosion resistance behaviour somewhere between these HCCS alloys. Furthermore, in these dual-structure steels, preferential corrosion degradation on ferrite then followed by martensite, this was mainly due to the C content is higher in martensitic phase that led to phase stability than Fe-rich ferrite phase [23,24]. Meaning that martensite performed Fig.…”

Multi performance optimization in machining of EN31-535A99SS with interchangeable straight cemented tungsten carbide-cobalt mixed (WC–Co) insert grade (CSTC—K20) using Taguchi coupled grey relational analysis

“…As shown in Fig. 4 further advancements of these inserts are based on the improvements of the microstructure through the additions of WC and with this addition the hot hardness, transverse rupture strength, oxidation resistance, and thermal conductivity can be significantly increased [14].…”