1.2344 hot work mold steel (equivalent grades: H13 in the U.S., SKD61 in Japan, 4Cr5MoSiV1 in China) is a high-toughness, pressure-resistant hot work tool steel widely used in high-temperature and high-pressure applications such as die casting, extrusion, and hot forging.
1. Superior High-Temperature Performance
High-Temperature Strength and Hardness: Maintains a hardness above HRC50 at 500–650°C, with a tensile strength of 1,500–1,700 MPa and yield strength ≥1,200 MPa. For example, in aluminum alloy die-casting molds, it can withstand continuous impact from 680°C molten aluminum alloy, reducing surface thermal cracking by 60% compared to traditional Cr12MoV steel and extending mold life from 80,000 cycles to 250,000 cycles.
Thermal Fatigue Resistance: Optimized chemical composition (e.g., molybdenum and vanadium) significantly enhances crack propagation resistance during repeated heating-cooling cycles. In extrusion molds for aerospace components, after 200,000 continuous extrusion cycles at 500°C, dimensional accuracy of the mold cavity remains within ±0.02 mm, with a lifespan three times longer than traditional H11 steel.
2. Excellent Machinability
Cutting and Polishing Performance: High material uniformity (achieved through electroslag remelting) allows cutting speeds of 15–25 m/min and feed rates of 0.08–0.15 mm/r. When paired with CBN tools, surface roughness as low as Ra0.4 μm can be achieved. A home appliance manufacturer used this material for refrigerator liner molds, achieving over 90% surface gloss.
Weldability and Repairability: For localized damage, a process of "preheating to 200°C + nickel-based welding electrode (ENiCrFe-3)" followed by stress-relief tempering at 580°C ensures a welding joint hardness match of ≥92% with the base material. After repair, mold life recovers to 88% of that of a new mold.
3. Corrosion and Wear Resistance
Oxide Film Protection: Chromium forms a dense oxide film, while vanadium carbides impede melt penetration. In aluminum alloy die casting, surface thermal cracking is reduced by 55% compared to 3Cr2W8V steel, with mold life extended from 100,000 cycles to 300,000 cycles.
Coating Enhancement: Combined with PVD coatings (e.g., AlTiN) or laser cladding technology, mold life is further improved. An energy equipment manufacturer reported that after depositing an AlTiN coating, mold life increased from 200,000 cycles to 450,000 cycles, with a coating-substrate bond strength of 80 MPa.
