Graphite crucible, as an important equipment widely used in high-temperature melting, chemical experiments, and industrial production, has excellent thermal conductivity, high temperature resistance, and chemical stability, making it a core tool in fields such as metal smelting and precision casting. However, due to its material properties and harsh usage environment, scientific maintenance measures are crucial for extending its service life. The following provides a multidimensional description of its maintenance details:
1、 Storage environment management
-Temperature and humidity control
-The storage environment should be kept dry and ventilated, with a recommended temperature range of 5 ℃~25 ℃ and a relative humidity not exceeding 60%. Wooden supports or moisture-proof pads should be laid on the ground, with a height of ≥ 20cm above the ground. It is strictly prohibited to directly contact the brick soil or cement ground to prevent moisture absorption.
-During the rainy or high humidity season, it is necessary to increase the frequency of desiccant application and, if necessary, introduce dry nitrogen gas to maintain internal dryness.
-Stacking and turnover
-Bulk crucibles should be placed in layers on wooden frames, with soft cloth separating each layer; Packaged items (such as wooden boxes and straw bags) should be stacked high and stacked regularly (at least once every two months) to avoid long-term deformation of the lower layer under pressure.
-When idle for a long time, regular "air burning" treatment can be carried out to remove adsorbed gases and maintain stable material properties.
2、 Use process specifications
-Preheating and Temperature Control
-Newly purchased crucibles need to undergo a stepwise heating process: first, raise the temperature to 200 ℃ at a rate of 100 ℃/hour for 2 hours to remove water, and then raise the temperature to 800 ℃ at a rate of 150 ℃/hour for 1 hour to complete lattice stabilization treatment.
-Avoid direct flame spraying at the bottom during use, use a lateral burner for uniform heating, and control temperature fluctuations within ± 50 ℃. Rapid cooling and heating can easily cause thermal stress cracks.
-Guidelines for Feeding Operations
-Following the principle of "small quantity, multiple times, layered feeding", cold materials need to be preheated to above 150 ℃ before feeding, and large metal ingots should be crushed into ≤ 5cm fragments before feeding.
-The liquid level should be 10-15 cm away from the crucible mouth to prevent splashing and overflow, which may cause safety hazards.
3、 Cleaning and Restoration Strategy
-Residual removal
-Immediately clean the slag on the crucible wall with a graphite scraper after melting is completed. Stubborn residue can be chemically cleaned using a molten salt mixture at 400 ℃.
-Do not use metal tools to scrape during daily cleaning. It is recommended to use compressed air blowing and a soft bristled brush for wiping.
-Damage assessment and repair
-Minor cracks can be removed by grinding and coated with fire-resistant repair material; If the local thinning exceeds 20% or there are penetrating cracks, it should be promptly scrapped and replaced.
-Silicon infiltration pollution requires the removal of oxides during furnace dismantling and the wiping of insulation covers and other components with ethanol.
Through the above systematic maintenance, the economy and safety of graphite crucibles can be significantly improved. Suggest combining IoT technology to achieve intelligent monitoring and further promote the upgrade of management mode.