This news article was originally written in Spanish. It has been automatically translated for your convenience. Reasonable efforts have been made to provide an accurate translation, however, no automated translation is perfect nor is it intended to replace a human translator. The original article in Spanish can be viewed at Soluciones completas para las certificaciones de los tratamientos térmicos

Complete solutions for the certification of heat treatment

Department of heat treatments of entheses21/01/2008

January 21, 2008

Increasingly over the automotive industry is adopting standards of the aviation industry in order to ensure maximum uniformity of the treated parts. To do this required annual audits according to ISO/TS 16949: 2002. Based on the same, the AIAG (Automotive Industry Action Group) has developed the CQI-9 protocol that describes the procedure to follow according to the different types of ovens and treatments. Here we will refer only to three of the magnitudes to control: temperature, carbon potential, and the dissociation of ammonia.

As regards the temperature, the standard used is the AMS 2750D, which describes both the characteristics of the probes and equipment of measurement, regulation and registration to use, and SAT (accuracy of the system test) tests and your (uniformity of temperature control).

The probes for control, regulation and registration of temperatures must be located in the area of work or as close as possible to it. In the case of operating in the same range of temperatures, the accuracy of the system (TSS) test can be done without extracting the tube and while the oven is working. To this end, Pyro Controle has designed a few probes that allow their calibration 'in situ' and without interruption of the production process: opens the top of the head of probe connections and a reference sensor is inserted into the tube internal guide up to the tip of the probe. After stabilization, measured the temperature of the reference with an appropriate gauge sensor and determines the difference with the probe installed in the oven.

Pyro Controle can also give the sensors of reference with the certificate of calibration on the necessary points, with full traceability and certification Cofrac (France).

Videorecorder paperless 'low cost' C.A Pyrotracer 650LV.

For the registration of data such as opening doors, control valves, motors, etc., as well as temperatures, speeds of tape, pressure, flow, etc. during the treatment process, Pyro Controle offers the Registrar without paper Pyrotracer of 18 analog channels and provides a program for download, evaluation, and the stored inviolable of data on a PC computer. The instrument has an ethernet port and optionally another RS232/485 series.

Similarly, the AMS 2750D standard requires verification of the uniformity of temperature in the Chamber of the oven's heat treatments. For this test, they must be placed in an appropriate amount - specified by the standard own - and appropriately distributed sensors previously calibrated to the temperature of the oven. The signal of the same shall be registered by a team that in addition to ensure the inviolability of the stored data, admit the correctness of the reading of each sensor connected to the same, allows to define the tolerance admitted in the temperature of the oven and set a fixed rate of registration of data, among other requirements.

To perform this test, Super Systems Inc. has developed the SDS 8020 (40), a portable and independent of 20 or 40 input channels, galvanic isolated each other and total and team independently configurable for thermocouples, current or voltage signalsIt meets all the requirements of the AMS 2750D and that can develop from a PC via the communication programme with which certificate is delivered, the corresponding data from the oven, values and temperature curves, drawings and photos with the situation of the probes factors of correction, company and person certification, data of the own team, result of the trial, judgements and table with extreme values measured data.

Daots logger multichannel SDS 8020 (40).

Tubes used for this test are usually casing type Thermocouple type N, and in any case, with a certificate of calibration in the points to be measured in the oven and must meet the requirements of the AMS 2750D. Pyro Controle can also give this type of probes.

Control of carbon potential and the dissociation of ammonia, other two requirements

But the CQI-9 also refers to the extent of the potential of carbon in generators of endogás and furnaces of treatment, as well as the degree of dissociation of ammonia in nitriding furnaces.

The potential of carbon requires a measurement and record continuously the same - or dew point - and to have a means of checking. Super Systems supplies oxygen Gold Probe probes and all the necessary accessories for measurement and regulation in continuous, and also fixed and portable analyzers from the point of dew - DP 2000 - or 3 gases - the PGA 3500 - of the composition of the atmosphere.

Oxygen Gold Probe probes.

Finally, for the measurement in continuum of dissociation of ammonia in nitriding and nitrocarburizing gas furnaces, we rely on the K1550 Analyzer Hitech Instruments, based on the principle of measurement of the thermal conductivity of gases. This method is of a very high stability, not requiring any adjustment in long years of service. Calibration is performed using the own air and a mixture of gases.