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CN-122016768-A - Residual magnesium trace detection method for nodulizing rate of die plate casting iron liquid of injection molding machine

CN122016768ACN 122016768 ACN122016768 ACN 122016768ACN-122016768-A

Abstract

The invention relates to the technical field of spectrum analysis, and discloses a residual magnesium trace detection method for nodulizing rate of molten iron of a template casting of an injection molding machine, which comprises the following steps: the method comprises the steps of generating plasma by exciting a pulse radiation unit to ablate the surface of molten iron, synchronously collecting signal intensities of a first wave band and a second wave band, determining a transient energy level distribution parameter of the plasma based on the ratio of the signal intensities, monitoring a time domain evolution track of the signal intensities, comparing the track with a signal-to-noise ratio threshold value determined based on a background signal attenuation characteristic point, triggering a gating window to extract trace magnesium spectrum data and output evaluation parameters when the parameters reach the threshold value.

Inventors

  • MAO JIANFENG
  • JIANG AIMEI
  • KAN WEILIANG
  • JI HANCHENG
  • XU JINFENG

Assignees

  • 湖南鑫泉科技有限公司

Dates

Publication Date
20260512
Application Date
20260413

Claims (10)

  1. 1. The method for detecting the trace amount of residual magnesium of the nodulizing rate of the die plate casting iron liquid of the injection molding machine is characterized by comprising the following steps of: step 101, utilizing an excitation pulse radiation unit to ablate the surface of molten iron of a template casting of the injection molding machine so as to generate plasma; 102, synchronously acquiring the signal intensity of a first wave band and the signal intensity of a second wave band in the plasma evolution process, wherein the first wave band corresponds to an atomic spontaneous emission spectrum line of magnesium element in molten iron, and the second wave band corresponds to a continuous background radiation spectrum line of plasma; Step 103, determining a transient energy level distribution parameter of the plasma based on a transient ratio of the signal intensity of the first wave band to the signal intensity of the second wave band, and monitoring a time domain evolution track of the transient energy level distribution parameter along with a plasma cooling process; 104, comparing the time domain evolution track of the transient energy level distribution parameter with a signal-to-noise ratio characteristic threshold value determined based on a background signal attenuation characteristic point, and triggering to open an acquisition gating window to extract trace spectrum data of magnesium element in the molten iron when the transient energy level distribution parameter reaches the signal-to-noise ratio characteristic threshold value; Step 105, calculating mass fraction of magnesium element in the molten iron according to trace spectrum data and a preset element mapping model; And 106, determining and outputting an evaluation parameter representing the spheroidization quality of the template casting of the injection molding machine according to the mass fraction of the magnesium element.
  2. 2. The method for detecting residual magnesium trace of nodulizing rate of die plate casting iron liquid of injection molding machine according to claim 1 is characterized by comprising the step 201 of synchronously collecting reference spectral line intensity of matrix iron element in plasma, the step 202 of identifying a physical turning point of plasma from thermodynamic equilibrium state to atomic spontaneous emission main state transition according to first derivative of the reference spectral line intensity and locking the opening time of a collection gate window at the physical turning point when the step 104 is executed.
  3. 3. The method for detecting residual magnesium trace of nodulizing rate of die plate casting iron liquid of injection molding machine according to claim 1, wherein the central wavelength of the first wave band is 285.21nm, the central wavelength of the second wave band is 286.00nm, and in step 103, the transient energy level distribution parameter is defined as the real-time intensity ratio of the peak intensity at 285.21nm to the background signal intensity at 286.00 nm.
  4. 4. The method for detecting the trace amount of residual magnesium of the nodulizing rate of the molten iron of the template casting of the injection molding machine according to claim 1, which is characterized by comprising the step 401 of delivering inert protective gas with the flow rate of 5L/min to 15L/min to an action area of an excitation pulse radiation unit so as to form a local reducing gas phase interface on the surface of the molten iron, wherein the local reducing gas phase interface is used for inhibiting the secondary oxidation loss of magnesium atoms.
  5. 5. The method for detecting residual magnesium trace of nodulizing rate of molten iron of template castings of injection molding machines according to claim 2 is characterized by comprising the steps of 501, extracting iron element spectral line pairs with excitation energy level difference larger than 2eV in plasmas, 502, establishing thermodynamic temperature feedback closed loop based on intensity ratio of the iron element spectral line pairs, and correcting integral width of an acquisition gate window in 104 when the temperature of the molten iron surface fluctuates within a range of 1400-1550 ℃.
  6. 6. The method for detecting residual magnesium trace of nodulizing rate of die plate casting iron liquid of injection molding machine according to claim 1, wherein step 105 comprises the steps of establishing an energy balance mapping rule between rare earth element ion lines and signal intensity of a first wave band, and identifying occurrence states of magnesium elements in a high-temperature melt by utilizing cooperative correlation characteristics among heterogeneous elements.
  7. 7. The method for detecting residual magnesium trace of nodulizing rate of die plate casting iron liquid of injection molding machine according to claim 4 is characterized by comprising the steps of 701, synchronously monitoring characteristic spectral line intensity of inert shielding gas conveyed in 401, 702, calculating a change coefficient of light path penetration rate according to attenuation of the characteristic spectral line intensity of the inert shielding gas, and performing amplitude gain compensation on trace spectrum data obtained in 104 according to the change coefficient.
  8. 8. The method for detecting residual magnesium trace of nodulizing rate of molten iron of template casting of injection molding machine according to claim 1, wherein in step 104, the opening time delay D gate of the acquisition gate window satisfies the following logic: Wherein D gate is the opening time delay of the acquisition gate window, t opt is the sampling time when the transient energy level distribution parameter reaches the signal to noise ratio characteristic threshold for the first time, and δt is the preset system electric signal transmission time delay compensation quantity.
  9. 9. The method for detecting residual magnesium trace of nodulizing rate of die plate casting iron liquid of injection molding machine according to claim 1, wherein the element mapping model in step 105 is established by collecting a spectrum evolution curve of standard sample blocks with known magnesium content in a range of 1450-1500 ℃, and extracting real-time ratio characteristics of signal intensity of a first wave band and signal intensity of a second wave band to construct a quantitative mapping matrix for eliminating blackbody radiation interference.
  10. 10. The method for detecting residual magnesium trace of nodulizing rate of molten iron of template casting of injection molding machine according to claim 1 is characterized by comprising the steps of 1001 outputting a quality feedback signal representing component deviation of molten iron when the measured evaluation parameter corresponds to the nodulizing rate being lower than 90%, and 1002 calculating magnesium content compensation data corresponding to the nodulizing agent added to molten iron of template casting of injection molding machine according to mass fraction of magnesium element.

Description

Residual magnesium trace detection method for nodulizing rate of die plate casting iron liquid of injection molding machine Technical Field The invention belongs to the technical field of spectral analysis, and relates to a residual magnesium trace detection method for nodulizing rate of a die plate casting iron liquid of an injection molding machine. Background In the current smelting process of spheroidal graphite cast iron for a heavy injection molding machine template, the magnesium content in the molten iron directly influences the spheroidization grade and mechanical property of a casting, a laser induced breakdown spectroscopy technology is used as an on-site rapid component analysis means, the surface of the molten iron is ablated by utilizing high-energy laser pulses to generate plasmas, the real-time monitoring of the content of metal components is realized by collecting and analyzing spectral signals emitted by the plasmas, the plasma excitation process is accompanied by extremely strong continuous background radiation under the high-temperature working condition of 1450-1550 ℃, the background radiation is caused to show non-stable step fluctuation by the thermal convection of the surface of the molten iron and the dynamic evolution of an oxide film, and trace magnesium element characteristic spectral lines with the concentration lower than 0.04% are covered by the randomly changed background signals, so that the identification degree of target characteristic peaks in spectral data acquired by a detection system is reduced. In order to inhibit background interference, the conventional method intercepts signals by increasing excitation energy or setting fixed sampling delay time, and as atomic fluorescence life and continuous background radiation are overlapped on a time evolution axis, transient jump of liquid level emissivity causes change of plasma quenching rate, technical contradiction of mismatch between a trigger window and a plasma physical evolution stage cannot be solved by simply depending on the lifting excitation energy level, so that random deviation is generated in measurement data, and industry attempts to introduce polymorphic identification and compensation logic, for example, china patent with an authorized bulletin number of CN114136458B discloses a polymorphic online detection method and system for temperature of molten metal fluid, a deep neural network is used for identifying on-site dust interference state to construct different detection models, and has reference value in the aspect of environmental light path compensation, the polymorphic division focusing external dust concentration macroscopic classification based on image processing does not touch the transient physical characteristics of plasma, trace element detection challenges are in that atomic radiation signals and blackbody background noise are deeply coupled in nanosecond scale, and trace element step fluctuation cannot be solved by depending on external environment state identification when plasma internal energy level distribution turning points are not captured in real time. Therefore, how to utilize the physical state characteristics in the plasma evolution process to determine the spectrum acquisition time in real time, realize the suppression of non-stationary background radiation interference, and improve the measurement stability of residual magnesium trace, and is the technical problem to be solved by the invention. Disclosure of Invention In order to solve the problems in the background technology, the technical scheme of the invention is as follows, the trace detection method for the residual magnesium of the nodulizing rate of the casting iron liquid of the template casting of the injection molding machine comprises the following steps: step 101, utilizing an excitation pulse radiation unit to ablate the surface of molten iron of a template casting of the injection molding machine so as to generate plasma; 102, synchronously acquiring the signal intensity of a first wave band and the signal intensity of a second wave band in the plasma evolution process, wherein the first wave band corresponds to an atomic spontaneous emission spectrum line of magnesium element in molten iron, and the second wave band corresponds to a continuous background radiation spectrum line of plasma; Step 103, determining a transient energy level distribution parameter of the plasma based on a transient ratio of the signal intensity of the first wave band to the signal intensity of the second wave band, and monitoring a time domain evolution track of the transient energy level distribution parameter along with a plasma cooling process; 104, comparing the time domain evolution track of the transient energy level distribution parameter with a signal-to-noise ratio characteristic threshold value determined based on a background signal attenuation characteristic point, and triggering to open an acquisition gating window to extrac