Effect of Titanium Addition on As Cast Structure and Macrosegregation of High‐Carbon High‐Chromium Steel

Abstract

In casting heavy ingots of high-chromium high-carbon cold work steels, macrosegregation develops in the center of the ingot, causing difficulties during subsequent hot working. Heat transfer and solidification of an industrial scale high-carbon high-chromium steel ingot was simulated and thereafter a laboratory scale representative ingot was designed to model the solidification of the industrial scale ingot. Titanium in the range of 0.3-1% was added to the high-chromium high-carbon (12%Cr-2%C) steel during melting process. Microstructures, macrosegregation and phase formations were studied using optical microscopy, scanning electron microscopy, energy dispersive X-ray spectrometry, wave dispersive X-ray spectrometry, optical emission spectroscopy, and X-ray diffraction. Addition of 0.3% titanium was sufficient to diminish the macrosegregation; however it did not have a significant effect on the grain size. Addition of 0.7 and 1% titanium had a substantial effect on grain size in the longitudinal direction and refined the primary carbides structure. The formation of small TiC carbides that precipitated before solidification of liquid iron acted as nuclei for primary pro-eutectic austenite grains.

Effect of Titanium on the Microstructure and Mechanical Properties of High-Carbon Martensitic Stainless Steel 8Cr13MoV

“…This is attributed to the precipitation of TiCs, which served as heterogeneous nucleation sites for liquid steel. The present result is consistent with the findings that the addition of titanium in high-carbon high-chromium steel or cast iron could refine the eutectic carbides M7C3 and the grain size of the steel as reported by other researchers [26,27,29].…”

“…Titanium is a strong carbide-forming element, and its ability to combine with carbon is higher than that of chromium [26]. Formation of TiC could partially substitute M7C3 in high-carbon high-Cr tool steel, consequently improving the crack resistance of the steel [14].…”

Microstructure and Properties’ Evaluation of W18Cr4V Modified by Fe–Zr–Nb–N–B Nano‐Powder Inoculants

“…As we know, M6C is not easy to break in the forging process, which seriously affects the macroscopic properties of HSS. [17][18][19][20][21][22][23] After inoculation, as shown in Figure 4b, the size of the M6C Ledeburite was significantly reduced, and fishbone carbide was transformed from a coarse mesh into a long and slender strip, which was more conducive to be broken in the forging process.…”

Austenitic Grain Growth Behavior during Austenization in an Aluminum-Alloyed 5% Cr-Mo-V Steel

“…Annealing, austenitizing, and tempering are conventional thermal processes that guarantee the steel possessing excellent mechanical properties. In the austenitizing process, the austenite grain size constitutes one of the structural factors that will control the diffusive and diffusionless phase transformation, precipitation, and thus influence the resulting mechanical properties such as strength, hardness, toughness, and ductility . In addition, alloying is an effective way to modify the microstructure and improve the mechanical properties of this kind of die steel.…”