Forging processing technology
Forging molybdenum rods is the core processing technology for high-end molybdenum products. It differs from ordinary sintered molybdenum blocks. Through high-temperature plastic deformation, the internal structure of the material is thoroughly optimized, addressing the problems of loose sintered blocks, numerous pores, low strength, and easy cracking. It is currently the mainstream production process for molybdenum rods used in high-temperature furnaces, glass metallurgy, semiconductors, and precision machining fields. The entire process relies on powder metallurgy pre-preparation and multiple high-temperature forging and rolling processes.
The entire process precisely controls temperature, deformation, and impurities, ultimately producing high-density, high-strength, high-temperature-resistant, and stable industrial-grade forged molybdenum rods, covering a full range of grades such as pure molybdenum, molybdenum-lanthanum alloy, and TZM alloy.
For the forging of large-diameter molybdenum rods (Φ30mm and above), the process difficulty has significantly increased, which is also the technical barrier in the industry. The cross-section of large-sized molybdenum blocks is thick and has poor heat dissipation, easily causing internal grain differentiation and insufficient compaction in the core. In production, a free forging + rotary forging composite process is adopted, combined with multiple intermediate annealing treatments, and is heated at 1000–1200℃ for constant temperature holding to eliminate processing stress, uniformly refine grains, completely weld internal micro-pores, and enable the overall density of the billet to exceed 10.1g/cm³, achieving a unified density of the inner and outer materials, fundamentally solving industry problems such as machining cracks, high-temperature stress cracking, and deformation under long-term use.
After forging, the molybdenum rods enter the finishing treatment stage. Through professional straightening equipment, the bending degree of the rods is precisely corrected, and the straightness is strictly controlled ≤1mm/m, meeting the requirements of industrial assembly and precision processing. Subsequently, according to customer needs, different surface treatment processes are provided, including black skin forged rods with original color, oxidized matte acid-washed rods, high-gloss precision-turned/milled rods, suitable for different usage scenarios. Finally, through size tolerance testing, density testing, metallographic structure testing, and impurity component testing, the furnace number and batch can be traced throughout the process. Qualified products are vacuum-sealed to prevent moisture absorption, oxidation, and yellowing during maritime transportation and storage.
After the implementation of the entire forging process, the advantages of the finished molybdenum rods are very prominent: Compared to sintered molybdenum blocks, forged molybdenum rods have finer grains, uniform structure, and significantly improved high-temperature recrystallization performance. Pure molybdenum rods have enhanced high-temperature resistance and anti-cracking properties, molybdenum-lanthanum and TZM alloy rods have significantly optimized anti-warping and anti-bending performance.
Mechanical strength, wear resistance, and high-temperature stability have been comprehensively upgraded. They can be long-term adapted to strict conditions such as vacuum, inert atmosphere, high-temperature bearing, and precision machining .
