Effect of Ti Content on the Characteristics of MC-Type Primary Carbonitrides in H13 Steel

Effects of Ti and N Contents on the Characteristic Evolution and Thermal Stability of MC Carbonitrides Holding at 1250 °C in H13 Die Steel

“…AISI H13, a hot-work die steel, is widely used in die casting, extrusion, and hot forging, where H13 inevitably suffers from mechanical stress and thermal shock [1]. Large primary carbonitrides are precipitated for interdendritic segregation during the solidification process [2,3]. Extensive research has been conducted, showing that alloying elements such as Ti [2], Nb [3], and Mg [4], and rare-earth metals [5][6][7], could affect the precipitation and characteristics of carbonitrides in H13, in addition to the cooling rate and axial static magnetic field during the solidification process [8,9].…”

“…Large primary carbonitrides are precipitated for interdendritic segregation during the solidification process [2,3]. Extensive research has been conducted, showing that alloying elements such as Ti [2], Nb [3], and Mg [4], and rare-earth metals [5][6][7], could affect the precipitation and characteristics of carbonitrides in H13, in addition to the cooling rate and axial static magnetic field during the solidification process [8,9]. There are mainly two kinds of MC precipitates in H13, including V-rich and Ti-containing carbonitrides [2,10,11].…”

“…Extensive research has been conducted, showing that alloying elements such as Ti [2], Nb [3], and Mg [4], and rare-earth metals [5][6][7], could affect the precipitation and characteristics of carbonitrides in H13, in addition to the cooling rate and axial static magnetic field during the solidification process [8,9]. There are mainly two kinds of MC precipitates in H13, including V-rich and Ti-containing carbonitrides [2,10,11]. The precipitation temperature of Ti-containing MC precipitates can be significantly enhanced by increasing the concentration of Ti in H13.…”

“…The precipitation temperature of Ti-containing MC precipitates can be significantly enhanced by increasing the concentration of Ti in H13. Those precipitates can also act as the heterogeneous core of V-rich MC carbonitrides and influence the characteristics of MC carbonitrides in commercial H13 [2,10]. The quantities and sizes of precipitates increase as the Ti content increases from 0.011 wt% to 0.036 wt% in lab-scale H13 steel [10].…”

“…Many reports have shown that the mechanical properties and thermal fatigue life of hot-work die steels are directly influenced by the fine nanosized precipitates [14,15], of which the characteristics could be improved through heat treatments [16][17][18]. Nevertheless, the large and stable primary precipitates would severely deteriorate the toughness of H13 steel [2,19] and have an adverse effect on the precipitation of fine nano-sized precipitates [20] and performance of the steel. As a main type of primary carbonitrides in H13 steel, the large Ti-containing MC carbonitride with sharp corners and high hardness is much more stable than the V-rich MC carbonitride at a high temperature [5,21,22].…”