CQI-9 Heat Treat: Assess the Heat Treatment Process with the AIAG Checklist
What is CQI-9?
CQI-9 is the AIAG special process standard 'Heat Treat System Assessment' for verifying that supplier heat treatment processes are controlled. It organizes the heat treat process into elements and requires systematic auditing of personnel, equipment, process parameters, quench media, furnace temperature uniformity (TUS) and system accuracy (SAT). Results support supplier grading, order allocation and continuous improvement plans.
When to Use It
Use CQI-9 for second-party audits of heat treat suppliers in the automotive supply chain, for internal heat treat shop self-assessments, for new supplier qualification, and to support customer special process audit requirements. For critical furnace loads, verify load records and process curves so heat treat parameters are genuinely controlled. Quench media age can significantly affect hardness and distortion, so test it regularly and record replacement cycles.
How to Use It (Step by Step)
Assess items organized by CQI-9 tables A-F: job audit elements, quench media, equipment maintenance and calibration, furnace temperature uniformity and instrument accuracy reports, work instructions and records, personnel qualification, and preventive maintenance. Judge each item as conforming, non-conforming or not applicable and record the evidence. Non-conformances need explicit corrective actions with owners and completion dates, verified for effectiveness.
Key Formulas / Example
CQI-9 is an evidence-based audit, not a calculation. TUS and SAT must be run periodically per AMS2750 or the customer specification and the reports retained; TUS verifies temperature uniformity across the furnace, while SAT verifies agreement between the displayed and actual temperature. Scoring is based on the proportion of conforming items per element, and a critical element that fails directly affects the overall conclusion.