I. Raw material material grade (most crucial)
Ordinary graphite crucible: Lifespan 150-300 furnaces
High-purity graphite crucible: 300-600 furnaces
Isostatic pressure anti-oxidation graphite crucible: 600-1000 furnaces
The lower the material density and the higher the impurities, the more prone to cracking, oxidation, and perforation.
II. Melting temperature (most influential)
Melting aluminum, zinc, tin (600-800℃): Longest lifespan, 30% upward float
Melting brass, copper (1100-1300℃): Standard normal lifespan
Melting high-temperature alloys of gold and silver (above 1400℃): Lifespan decreases by 20%-40%
For every 100℃ increase in temperature, oxidation loss accelerates by a factor of two.
III. Types of metals melted and corrosion degree
Alkaline metals: Aluminum liquid has the strongest corrosiveness and is most likely to erode the inner wall of the crucible and become thinner
Copper alloys, scrap copper: High in impurities and slag, more prone to erosion and wear
Precious metals: Less impurities and less corrosion, longest lifespan
With oil stains, rust, or slag waste returned to the furnace, the lifespan is shortened by more than 40%
IV. Heating and cooling speed (determines whether it cracks)
Uniform heating, slow cooling: Maximum lifespan
Intense heating, direct water cooling at high temperature, rapid unloading:极易 produce dark cracks and cracking
The more frequent the temperature shock, the shorter the lifespan by more than 50%
V. Combustion atmosphere inside the furnace
Gas furnace, coke furnace： Large oxygen content, graphite is easily oxidized and thinned, shortest lifespan
Medium-frequency electric furnace, resistance furnace： Closed and oxygen-deficient environment, oxidation is slow, lifespan increases by 35%
The greater the furnace air intake, the faster the loss of material.
VI. Loading method and usage habits
Cold materials in large chunks are directly and forcefully dropped into the crucible： Likely to crack the bottom
Overloading the loading, the metal expands at high temperature and squeezes and cracks the top opening
Empty furnaces are subjected to long-term high-temperature dry burning： No material for cooling, inner walls quickly powderize and fall off
Each time leaving too much residual liquid, it causes the crucible to expand and crack
VII. Daily cleaning and maintenance methods
Soft chisel, soft brush cleaning： Does not damage the wall, normal lifespan
Iron hammer hard knocking, hard chisel forcefully scraping the inner wall： Directly knocks out internal damage, early
Residual furnace slag not cleaned, repeated sintering and penetration accelerate damage.
VIII. Placement and stress conditions of the crucible
Bottom suspended, improper placement, single-sided stress： Easily crack from the bottom
Multiple layers stacked to increase pressure, violent forceful unloading： Top opening is easily cracked
Furnace flame biased burning on one side, local high temperature rapidly damages.
IX. Post-treatment for anti-oxidation and maintenance
Regular application of graphite anti-oxidation coating： Lifespan increases by 25%-40%
Never doing protection： High temperature oxidation is fast, wall thickness continues to thin
Storage in humid environment, not drying directly used： First high temperature is likely to crack.
Why choose us?
1. Super high quality: Comprehensive control over every aspect from materials to processes.
2. Core technology fully controllable: Proficient in key processes such as high-temperature graphitization and purification, supporting 72-hour non-standard customization response.
3. Ultimate quality guarantee: High-purity products reach 5N + purity, resistant to 3000℃ high temperature + strong corrosion, with full batch traceable testing.
4. Uninterrupted full-cycle service: Large-scale production + 5-7 days small-batch delivery, 24-hour technical response + on-site support.
