Abstract
Semisolid metal processing is a relatively new technology that offers several advantages over liquid processing and solid processing because of the unique behaviour and characteristic microstructure of metals in this state. With the aim of finding a minimum process chain for the manufacture of high-quality production at minimal cost for forming, the microstructural evolution of the ledeburitic AISI D2 tool steel in the semisolid state was studied experimentally. The potential of the direct partial remelting (DPRM) process for the production of AISI D2 with a uniform globular microstructure was revealed. The liquid fraction was determined using differential scanning calorimetry. The microstructures of the samples were investigated using an optical microscope and a scanning electron microscope equipped with an energy dispersive spectroscopy analyser, while X-ray phase analysis was performed to identify the phase evolution and the type of carbides. Mechanical characterisation was completed by hardness measurements. The typical microstructure after DPRM consists of metastable austenite which was located particularly in the globular grains (average grain size about 50 μm), while the remaining interspaces were filled by precipitated eutectic carbides on the grain boundaries and lamellar network.
Highlights
AISI D2 is the most commonly used high-carbon and highchromium cold-work tool steel
The absence of MC carbide in the as-received AISI D2 tool steel can be explained by the soft annealing process at 850∘C due to dissolution temperature of MC carbide at 740∘C
The current study shows that the microstructure was composed of metastable austenite which was located in the globular grains, while the remaining interspaces were filled by precipitated eutectic carbides on the grain boundaries and lamellar network
Summary
AISI D2 is the most commonly used high-carbon and highchromium cold-work tool steel. It has many attractive properties such as high wear resistance, high compressive strength, and high hardness after hardening which can be an advantage for a variety of industrial applications such as mill rolls, blanking dies, and punches. The direct partial remelting method (DPRM) is considered one of the most effective and commercially viable solid state processes (especially high-melting-point metals) to produce a nondendritic microstructure in order to gain some insight into the microstructural development of the starting material when in the semisolid state. Fe Balance the conventional feedstock preparation routes, like StressInduced and Melt-Activated (SIMA), Recrystallization and Partial Melting (RAP), and various others [8] This indicates a widening of the range of potential routes to thixoformable microstructures. Due to the growing demand for cold-work tool steel in various industrial applications, it is crucial to improve the fabrication technique because complex shapes involve an extensive and costly workshop effort. This study was employed to characterize the microstructural spheroidisation and phase transformations of AISI D2 cold-work tool steel at the isothermal temperature during partial remelting method
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
