[Research on the temperature field detection method of large cylinder forgings during heat treatment process based on infrared spectra].

In order to grasp the changes of the forging's temperature field during heat treatment, a temperature field detection method based on infrared spectra for large cylinder forgings is proposed in the present paper. On the basis of heat transfer a temperature field model of large barrel forgings was established by the method of separating variables. Using infrared spectroscopy the large forgings temperature measurement system was built based on the three-level interference filter. The temperature field detection of forging was realized in its heat treatment by combining the temperature data and the forgings temperature field detection model. Finally, this method is feasible according to the simulation experiment. The heating forging temperature detection method can provide the theoretical basis for the correct implementation of the heat treatment process.

[A method of temperature measurement for hot forging with surface oxide based on infrared spectroscopy].

High temperature large forging is covered with a thick oxide during forging. It leads to a big measurement data error. In this paper, a method of measuring temperature based on infrared spectroscopy is presented. It can effectively eliminate the influence of surface oxide on the measurement of temperature. The method can measure the surface temperature and emissivity of the oxide directly using the infrared spectrum. The infrared spectrum is radiated from surface oxide of forging. Then it can derive the real temperature of hot forging covered with the oxide using the heat exchange equation. In order to greatly restrain interference spectroscopy through included in the received infrared radiation spectrum, three interference filter system was proposed, and a group of optimal gap parameter values using spectral simulation were obtained. The precision of temperature measurement was improved. The experimental results show that the method can accurately measure the surface temperature of high temperature forging covered with oxide. It meets the requirements of measurement accuracy, and the temperature measurement method is feasible according to the experiment result.

[Research on high-precision temperature measurement system based on near infrared spectroscopy].

At present, the interference from outside radiation under the complex environment is difficult to eliminate by using the infrared thermometry method. It leads to the low measurement accuracy. In the present paper, a high-precision infrared temperature measurement system was designed. The light filter method is presented in this system. The broadband filters and three-level interference filter were combined in this method. According to the method, the near-infrared spectra sent out by high temperature object is filtered. The high temperature background light and the environment obtrusive light are filtered out. In this way, two monochromatic spectra are obtained. The radiation power ratio is received after receiving by the infrared detector. Then the temperature is obtained by calculating. In this system, the bandwidth of monochromatic spectrum permeated is only 1 nm. The inhibition of radiation from background light and ambient light except transmittance spectrum is up to 8 orders of magnitude. The measurement error caused by the ambient temperature heating of the measured object is reduced. The accuracy of the temperature measurement system is improved. Finally, the temperature measurement system is feasible according to the experiment result. The precision reached to 0.2%.