What is CQI9 ?
CQI-9, formally known as “CQI-9 Special Process: Heat Treat System Assessment (HTSA),” is a standard developed by the Automotive Industry Action Group (AIAG). It is designed to ensure the consistency and reliability of heat treatment processes used in the manufacturing of automotive components.
The HTSA is applicable to sites where customer-specified parts for production or service are processed throughout the automotive supply chain.
There are Nine Process Tables that are specific to the Heat Treat Processes as shown below:
Process Table A – Ferrous
- Carburizing
- Carbonitriding
- Carbon Restoration or Correction
- Neutral Hardening (Quench and Temper)
- Martempering
- Tempering
- Precipitation Hardening – Aging
Process Table B – Ferrous
- Nitriding (Gas)
- Ferritic-Nitrocarburizing (Gas or Salt)
Process Table C – Aluminum
Process Table D – Ferrous
Process Table E – Annealing, Normalizing, and Stress-Relieving
- Conformance to CQI-9 is required for organizations that perform annealing, normalizing, or stress-relieving to achieve the desired final characteristics of the part.
Process Table F – Low Pressure Processing (Carburizing/Carbonitriding/Neutral Hardening)
Process Table G – Sinter Hardening
Process Table H – Ion Nitriding
Process Table I – Hot Stamping
PROCESS TABLE A – Carburizing / Carbonitriding / Carbon Restoration / Hardening / Austempering / Martempering / Tempering / Precipitation Hardening – Aging
The Customer may have additional requirements, e.g. inspection testing, greater frequencies. When performing the job audit, the auditor shall verify heat treater is conforming to the Customer’s requirements.
PROCESS AND TEST EQUIPMENT CHECKPOINTS
- Recording instruments are required for temperature controlling devices and protective atmosphere monitoring unit, e.g. dew point, oxygen probe, or other atmosphere controlling devices.
- A program for furnace, generator, and oxygen probe burnout is required (applies to carbon bearing atmospheres).
- Furnace loading weigh scales shall be verified quarterly and calibrated annually at a minimum.
- Dew pointers, gas analyzers, spectrometers, and carbon IR combustion analyzers (shim stock/foil analysis), used to verify carbon potential in furnaces, shall be calibrated annually at a minimum.
- Verification of spectrometers and carbon IR combustion analyzers (shim stock/foil analysis) shall be performed daily or prior to use.
- Verification of gas analyzers with zero gas and span gas when used as the back-up verification shall be performed weekly at a minimum. When used for primary control of the carbon-bearing atmospheres, verification shall be daily.
- Atmosphere controllers shall be calibrated quarterly (single-point or multi-point calibration). A six month calibration interval is allowed if multi-point calibration is utilized.
- Laboratory and Test equipment used for product and process testing shall be calibrated annually at a minimum, per the applicable national standard (e.g. ASTM, EN, JIS) or approved equivalent standard, and verified per internal procedure if not specified in the applicable standard.
- Files for testing hardness shall be verified per the Customer requirement.
- Refractometers typically used to check polymer quenchants and washer solutions shall be verified prior to use with distilled water.
PYROMETRY CHECKPOINTS
- Thermocouples and calibration of thermocouples shall conform to requirements.
- Calibration of instrumentation shall conform to requirements.
- System Accuracy Test (SAT) for all control, monitoring, and recording thermocouples shall conform
to requirements. - Temperature Uniformity Survey (TUS) shall be performed annually.
- Temperature uniformity tolerance for austentizing furnaces shall be +/- 15℃ (or +/- 25°F).
Temperature uniformity tolerance for tempering and precipitation hardening furnaces shall be +/-
10C (or +/- 20°F). - Temperature(s) for austentizing processes shall be controlled within +/- 10C (or +/- 15°F) of the set
point as evidenced by recording instruments. Furnace temperature shall be controlled with soak
times starting at the lower tolerance limit (as defined above). - For Continuous Furnaces, this requirement applies to the Qualified Work Zone.
- Temperature(s) for tempering and precipitation hardening processes shall be controlled within +/-
5C (or +/- 10°F) of the set point as evidenced by recording instruments. Furnace temperature shall
be controlled with soak times starting at the lower tolerance limit (as defined above). For Continuous Furnaces, this requirement applies to the Qualified Work Zone. - Non-contact thermometry devices used for temperature monitoring (e.g. infrared pyrometer, thermal imaging camera) shall be calibrated annually at a minimum in the temperature range to be used utilizing a blackbody device or per the manufacturer’s recommended procedure.
PROCESS MONITORING PARAMETERS
- Monitor primary temperature control instrument(s).
- Monitor atmosphere generation as applicable.
- Monitor primary furnace atmosphere control(s).
- Verify primary atmosphere control method by back-up method.
- For austenitizing salt baths: Salt chemistry (soluble oxides) or decarburization on the parts shall be checked.
- Monitor time in furnace, cycle time, or belt speed.
- Monitor load size, fixturing, or loading rate as applicable.
- Quench Media Process Parameters – Liquid
- Temperature
- Quench Level
- Agitation
- Quench Media Process Parameters – Gas
- Pressure in the quench cell.
- Fan speed or power.
- Cooling water temperature and flow rate.
- Quench Delay Time
- Temper Delay Time – The maximum delay time between quenching and tempering shall be specified on the control plan and monitored.
IN-PROCESS/FINAL TEST PARAMETERS
- Microstructure shall be checked at a low magnification of 100X and a high magnification of 400X or above.
Microstructure visual references shall be available. - Surface hardness (when specified).
- Core hardness (when specified).
- Case Depth (when specified).
QUENCHANT AND SOLUTION TEST PARAMETERS
- Polymer Quench Media
- Concentration (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- Daily)
- Cooling Curve Analysis (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- Every six month)
- Water Quench Media
- Suspended solids (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- Every six month)
- Salt Quench Media
- Analysis and Contaminants (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- Every six month)
- Brine or Caustic Quench Media
- Concentration and/or Specific Gravity (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- Daily)
- Suspended solids (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- Every six month)
- Oil Quench Media
- Water content, suspended solids, viscosity, cooling curve, maximum cooling rate, total acid, and flash point. (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- Every six month)
- Rust Preventive – Soluble Oil
- Concentration (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- 2x/week)
- Cleaning Solution
- Concentration of cleaner (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- Daily)
- Temperature of solution (required if temperature is specified to be above ambient temperature). (Requirements/Frequency- for Batch/Chamber furnance & Continuous furnace- each shift)
PROCESS TABLE B – Nitriding (Gas) and Ferritic-Nitrocarburizing (Gas or Salt)
PROCESS AND TEST EQUIPMENT REQUIREMENTS
- Recording instruments are required for tem perature controlling devices and protective atm osphere monitoring
unit, e.g. dew point, oxygen probe, or other atmosphere controlling devices. - A program for fumace and generator burnout is required. Not required for retort gas nitriding.
- Furnace weigh scales shall be verified quarterly and calibrated annually at a minimum.
- Gas analyzers, used to verify proper atmosphere in fumaces, shall be calibrated annually at a minimum.
- Laboratory and Test equipment used for product and process testing shall be calibrated annually at a minimum, per the applicable national standard (e.g. ASTM, EN, JIS) or approved equivalent standard, and verified per internal procedure if not specified in the applicable standard.
- Files for testing hardness shall be verified per the Customer requirement.
- Refractometers typically used to check polymer quenchants and washer solutions shall be verified prior to use
with distilled water.
PYROMETRY CHECKPOINTS
- Thermocouples and calibration of thermocouples shall conform to requirements
- Calibration of instrumentation shall conform to requirements
- System Accuracy Test (SAT) for all control, monitoring, and recording therm ocouples shall conform to requirements
- Temperature Uniformity Survey (TUS) shall be performed annually.
- Temperature uniformity tolerance shall be +/- 10C (15°F).
- Process temperature(s) shall be controlled within +/- 10C (or +/- 15°F) of the set point as evidenced by recording instruments. Furnace temperature shall be controlled with soak times starting at the lower tolerance limit (as defined above).
- For Continuous Fumaces, this requirem ent applies to the Qualified Work Zone.