Molybdenum Rod Type 366

Molybdenum Rod Type 366 (molybdenum rod 366) is a high-end refractory metal product specially developed for extreme high temperature and severe corrosion. As a typical representative of molybdenum-tungsten (Mo-W) solid solution alloys, the material consists of about 70% molybdenum and 30% tungsten. Compared with pure molybdenum, 366 molybdenum rods show excellent high temperature strength, excellent creep resistance and excellent corrosion resistance to molten glass and liquid metal at ultra-high temperatures. The product is manufactured by vacuum arc melting (VAR) or powder metallurgy (PM) process, and is specially designed for the working conditions where standard pure molybdenum or TZM alloys are prone to softening and failure. With precise dimensional tolerances and a wide range of surface state options, the Model 366 molybdenum rod has become a structural material for cutting-edge industries such as glass smelting and advanced metallurgy.

Basic Product Information

Product name: 366 molybdenum rod/Mo-30W alloy rod

Material category: molybdenum-tungsten (Mo-W) refractory alloy

Manufacturing process: Vacuum arc smelting (VAR)/powder metallurgy (PM);

Density: approximately 12.97 g/cm ³ (fine-tuned with specific tungsten content)

Melting point: > 2600 °C

Surface status options: black leather forged surface, alkali wash surface, polished glossy surface

Product form: Straight bar, customized length and machined parts

Chemical Composition (Chemical Composition)

The core feature of the 366 type is its high proportion of tungsten element, which fundamentally improves the high-temperature mechanical properties of the material:

Molybdenum (Mo): margin (about 70%)

Tungsten (W): 27%-33% (30% typical)

Impurities (C, O, N, H, Fe, etc.): Strictly control the total content ≤ 0.05% to ensure high purity and prevent high temperature embrittlement.

Production Process & Flow

The manufacture of the Model 366 molybdenum rod involves a highly controlled metallurgical process:

Powder mixing and pressing: High-purity molybdenum powder and tungsten powder are mixed in precise proportion, and then sintered into electrodes by isostatic pressing.

Vacuum arc melting (VAR): Smelting of sintered electrodes in a vacuum electric arc furnace ensures a high degree of chemical uniformity and eliminates internal pores.

Forging and rolling: The ingot is forged and rolled at high temperature to achieve the target rod diameter and refine the grain structure.

Machining and surface treatment: Machining or polishing by centerless grinder to make molybdenum rods achieve accurate dimensional tolerances.

Inspection: Non-destructive testing (ultrasonic flaw detection), size measurement and chemical composition analysis are carried out in strict accordance with ASTM standards.

Product Specifications

Diameter range: 3.0 mm to 165 mm (size can be customized according to demand)

Length: The standard length is 300mm, 500mm, 1000mm, or customized according to customer requirements.

Tolerance: Precision grinding tolerance (e.g. polishing rod tolerance of ± 0. 05 mm), in full compliance with customer drawings or international standards.

Technical Standards

Our Model 366 molybdenum rods are produced and tested in strict accordance with international specifications:

ASTM B387/B387M-23: Standard specification for molybdenum and molybdenum alloy bars, rods, and wires (explicitly covering Type 366).

ISO 898-1/DIN 975: Suitable for custom threaded rod applications.

AMS 7847/AMS 7848: Material specification for high performance refractory alloys.

Surface Treatment

Black Forged Surface (Black Forged): Retains the natural oxide layer produced by thermal processing, suitable for cost-effective structural parts.

Alkali Washed: Removes surface oxides and impurities to present a clean matte gray, which is very suitable for subsequent processing.

Polished/Bright Finish: Centerless grinding to mirror metallic gloss, providing excellent dimensional accuracy and corrosion resistance for precision parts.

Comparative Advantages: Type 366 vs. Mo1/Mo2/TZM (Advantages over Mo1/Mo2 and TZM)

When standard molybdenum and TZM alloys reach their thermal performance limits, Type 366 is an alternative:

Compared with Mo1 and Mo2 (pure molybdenum): pure molybdenum rods will show obvious strength decline and recrystallization embrittlement above 1000 °C. The 30% tungsten added to the Model 366 provides solution strengthening for superior tensile strength and creep resistance at temperatures exceeding 1400 °C.

Contrast TZM alloys (Mo-0. 5Ti-0.1 Zr): Although TZM has excellent high-temperature strength up to 1150 °C, it softens at extreme high temperatures. The Model 366 outperforms the TZM at ultra-high temperatures (> 1300 °C) and is significantly more resistant to molten glass and liquid metals. In addition, the 366 type does not experience a significant decrease in strength after TZM recrystallization annealing.

Key Application Areas (Main Application Areas)

Glass manufacturing: With excellent corrosion resistance to molten glass, it is widely used in glass electrodes, stirrers and furnace components.

Defense: rocket engine nozzles, reentry vehicle heat shields, and thrust vectoring control systems.

Advanced Metallurgy: Crucibles, thermocouple protection tubes and heating elements for high vacuum and high temperature sintering furnaces.

Semiconductors and Electronics: Sputtering targets, PVD (physical vapor deposition) chamber assemblies and special high temperature resistant fasteners.