Effect of selective-precipitations process on the corrosion resistance and hardness of dual-phase high-carbon steel

Abstract

It is commonly known that precipitation of secondary phase in non-ferrous alloys will affect the mechanical properties of them. But due to the nature of dual-phase low-alloy high-carbon steel and its high potential of precipitation of cementite, there is limited study on tailoring the mechanical and corrosion properties of this grade of steel by controlling the precipitation of different phases. Predicting and controlling precipitation behaviour on this grade of steel is of great importance towards producing more advanced applications using this low-cost alloy. In this study the new concept of selective-precipitation process for controlling the mechanical and corrosion behaviour of dual-phase low-alloy high-carbon steel has been introduced. We have investigated the precipitation of different phases using in-situ observation ultra-high temperature confocal scanning laser microscopy, image analyser – ImageJ, scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) and electron probe microanalysis (EPMA). Volume fraction of each phase including retained austenite, martensite and precipitated phases was determined by X-ray diffraction (XRD), electrochemical corrosion test by Tafel extrapolation method and hardness performance by nanoindentation hardness measurement. The experimental results demonstrated that, by controlling the precipitations inside the matrix and at grain boundaries through heat treatment, we can increase the hardness of steel from 7.81 GPa to 11.4 GPa. Also, corrosion resistance of steel at different condition has been investigated. This new approach will open new possibility of using this low-cost steel for high performance applications.

A Study of Induction Hardening Parameters for the DIN 42CrMo4 Alloy through Its Microhardness, Corrosion Resistance, and Microstructure Examination

“…Results showed that due to multi phases, hardness and corrosion performance improved, as fractions of bainite constituents increased at a low of martensite fractions. Similar studies [15,16] on high carbon low alloyed steel had also been executed at different austenitiza-tion temperatures with controlled soaking time and quench rates. Results have shown that hardness increases by using lower austenitization temperature at the expense of corrosion resistance.…”

“…Samples at 10 kW induction power have shown high corrosion resistance due to the presence of soft phases (i.e. pearlite), which keep decreasing as heating time increases with the formation of martensitic structure (since pearlite behaves as cathodic regions, while martensite becomes anodic [15]). Multiphase microstructure in steel always causes galvanic corrosion due to the presence of microcells.…”

“…9 s that an increasing trend in I corr values signifies the existence of coarse martensite causing a preferential attack on it. While samples treated at 14 to 18 kW power showed lath martensitic morphology without appreciable amount of retained austenite, resulting in the enhanced corrosion resistance with the absence or insignificant fraction of microcells, although a slight decrease in hardness was observed due to lower yield of martensitic fraction [14][15][16]25]. Moreover, carbon content also influences the corro-…”

Modification of Type B Inclusions by Calcium Treatment in High-Carbon Hard-Wire Steel

“…The wire rod rolled by structural steel with carbon content not less than 0.6% is called high-carbon hard-wire steel, which is widely used in construction, transportation, and other industries [1][2][3]. Nonmetallic inclusions affect the mechanical properties and corrosion performance of steel [4]. Compared with low-carbon steel, high-carbon steel has high hardness and low ductility and is more sensitive to nonmetallic inclusions [5,6].…”

A Kinetic Model for the Modification of Al2O3 Inclusions during Calcium Treatment in High-Carbon Hard Wire Steel

“…High-carbon hard wire steels are mainly applied in massive engineering projects such as bridges, cables, airports, power stations, and dams [ 1 , 2 , 3 ]. High-carbon hard wire products are drawn into filaments with a diameter of about 5 mm [ 4 , 5 ]. The hard inclusions with large sizes affect the steel yield and performance.…”