Vacuum induction melting furnace quality appraisal

vacuum induction melting furnace takes the synergy of high-frequency induction heating and high vacuum environment as its core principle. By optimizing the melting vacuum degree, power control accuracy and melting rate, it achieves the synergy of high purity, composition uniformity and tissue density of metal materials. It is widely used in the precision smelting fields of high-temperature alloys, special steels and rare metals. In the preparation of single crystal high-temperature alloys, it is used to eliminate oxide inclusions; in titanium alloy smelting, it meets low-gap element control; in intelligent scenarios, it ensures full traceability of smelting parameters and dynamic process adjustment. Compared with traditional equipment, the vacuum induction melting furnace has the characteristics of water-cooled copper crucible, ultra-high frequency power supply and intelligent leakage monitoring. It is the core equipment for the research and development of cutting-edge metal materials.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide vacuum induction melting furnace quality appraisal services. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for vacuum induction melting furnace quality appraisal.

With the upgrade of special metal smelting requirements, related quality dispute cases have increased significantly. The judicial dispute focuses on:

1. Dispute over performance indicators: the melting purity does not meet the standard and the temperature uniformity of the molten pool is extremely poor;

2. Material defects: the copper material of the induction coil has insufficient purity and the high-temperature resistant coating of the crucible peels off. ;

3, process problems: vacuum system leakage rate, cooling water flow fluctuation;

4, contract performance dispute: core modules (such as imported high-frequency power supply, intelligent mass flow controller) do not comply with the technical agreement.

According to the characteristics of the vacuum induction melting furnace, common quality identification technical methods include:

1, appearance inspection

Through visual observation, measurement and other methods, the appearance of the equipment or material is inspected to see whether there are obvious defects, damage, deformation and other problems. Appearance inspection can initially determine the quality of equipment or materials and provide clues for subsequent inspection and analysis.

2, physical and chemical testing

Physical and chemical testing is one of the commonly used methods in identification work, including chemical composition analysis, metallographic structure observation, mechanical property testing, etc. Through physical and chemical testing, the chemical composition, metallographic structure, mechanical properties and other indicators of the equipment or material can be accurately measured to determine whether it meets the quality requirements.

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An aviation material factory of the applicant signed a "Nickel-based Alloy Vacuum Induction Melting Furnace Purchase Contract" with an equipment manufacturer of the respondent, and it was agreed that the oxygen content should be ≤10ppm. After being put into production, the measured oxygen content reached 35ppm. The manufacturer argued that it was caused by impurities in the raw material sponge titanium.

identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of the "vacuum induction melting furnace", contract technical agreement, on-site investigation case materials and other data, and made the following quality analysis opinions:

The vacuum system leakage rate of the vacuum induction melting furnace involved in the case is 3×10⁻⁴Pa m³/s (agreement ≤5×10⁻⁵Pa·m³/s), and the copper coil purity is 99.93% (agreement ≥99.99%); the induction frequency fluctuates ±2kHz (agreement ±0.5kHz), resulting in uneven electromagnetic stirring of the molten pool.

The appraisal conclusion concluded that equipment sealing and material defects were the main reasons for the excessive oxygen content.

Vacuum induction melting furnace quality appraisal report should include:

1, appraisal purpose (such as product defect attribution, process compliance verification) and reference standards;

2, equipment model involved, control system version, melting parameter record;

3, detection method and Equipment list (such as GDMS, helium mass spectrometer);

4, detection data and failure correlation analysis (such as the impact of leakage rate on oxygen content);