Investigation of Primary Carbides in a Commercial-Sized Electroslag Remelting Ingot of H13 Steel

Abstract

The characteristics of primary carbides in a commercial-sized (one ton) electroslag remelting (ESR) ingot of AISI H13 steel were investigated. The interaction between the primary carbides and inclusions was also clarified. The results indicate that there are two types of primary carbides, V-rich and Mo-rich primary carbides, in the H13 ESR ingot. The quantity, the area fraction, and the size of the two primary carbides tend to decrease from the center of the H13 ESR ingot to the outer surface. Additionally, the V-rich primary carbide is obviously larger than the Mo-rich primary carbide. The Al 2 O 3 inclusion can promote the precipitation of the V-rich primary carbide, while the MnS inclusion encourages the precipitation of Mo-rich primary carbide. The CaO·Al 2 O 3 inclusion cannot act as the nucleation site for the precipitation of the two primary carbides. The solid fraction that the V-rich primary carbide begins to precipitate ranges from 0.965 to 0.983, and that for the Mo-rich primary carbide and the MnS inclusion change from 0.9990 to 0.9998 and from 0.989 to 0.990, respectively.

Industrial Trials on Preparation of Cerium‐Treated H13 Steel by Electroslag Remelting with Cerium‐Oxide Containing Slag

“…As shown in Figure 6 , the Al 2 O 3 and MnS inclusions are commonly located in the core of the primary carbide (including a V‐rich primary carbide (V‐PC) and Mo‐rich primary carbide (Mo‐PC)). We showed that the Al 2 O 3 and MnS inclusions have low disregistries with the primary carbides in H13 steel, [ 12,34 ] which indicates that the Al 2 O 3 and MnS inclusions could act as nucleation cores of primary carbides to generate large complex precipitates, as depicted in Figure 6. By modifying the Al 2 O 3 and MnS inclusions into Ce 2 O 3 or Ce 2 O 2 S, the formation of the large complex precipitates can be prevented due to the high disregistries between Ce 2 O 3 /Ce 2 O 2 S inclusions and primary carbides.…”

“…[8][9][10][11] Dendritic segregation in the H13 steel results in the generation of primary carbides. [12] In contrast, dendritic segregation is inherited after the hot forming process and creates banded structures, which have an adverse effect on the isotropy of the steel. [13,14] The banded structures and primary carbides would negatively affect the toughness of the H13 steel and reduce its service life.…”

Enhancement of Wear Resistance on H13 Tool and Die Steels by Trace Nanoparticles

“…However, it is difficult to add nanoparticles to liquid steel [35,47,61,62] due to the large specific gravity difference between liquid steel and nanoparticles [63][64][65][66][67]. Nanoparticles easily adsorb contamination and thus affect the strengthening effect [68,69]. In addition, the surface energy of nanoparticles is relatively high, so they are easy to agglomerate and difficult to disperse [70][71][72].…”

Effect of Ti Content on the Behavior of Primary Carbides in H13 Ingots

“…Therefore, the presence of Ti element is inevitable in molten steel during the actual smelting process because of the introduction of the alloying elements. Researchers have found large Ti-containing primary carbides in both as-cast H13 steel and H13 bars after heat treatment [16][17][18][19][20]. Large primary carbides as well as large Ti-containing carbonitride particles will act as a crack source, thus reducing the service life of H13 steel [21].…”

“…However, the effect of different Ti contents on primary carbides' behavior was not studied by Xie. Moreover, most researchers have ediscussed the characteristics of primary carbides from a two-dimensional perspective [16][17][18][19][20]. Few researchers have systematically studied the characteristics of the primary carbides in H13 steel from the three-dimensional perspective.…”