光谱法诊断TIG焊焊接电弧温度实验研究

An Experimental Study on Arc Temperature of TIG Welding Diagnosed by Spectroscopy

利用氩气作为TIG焊保护气体时,焊接电弧中会检测出丰富的低价氩离子及氩原子产生的线状光谱。焊接过程中火花熔化金属时产生等离子体激发氩保护气产生辐射,高温环境下氩气不与等离子体中的金属元素反应,并能隔离环境气体中的元素,使焊接过程产生的光谱结构能够准确反映焊接过程温度特征,因此,TIG焊焊接过程在线温度检测应用中,氩光谱信息分析应作为重点研究内容。用纯氩作为保护气,利用TIG焊在不同焊接电流条件下产生电弧光辐射,利用CCD光谱仪采集400nm—900nm光谱强度数据,参考NIST光谱数据库识别并标定其波长及辐射参数,以光谱信息分析和挖掘方法选定谱线组,利用多谱线斜率法对特定焊接参数条件下的TIG焊焊接电弧温度进行诊断。选定两组不同电流产生的电弧光谱来诊断焊接温度,通过对照分析并与已报道的氩原子及铁原子谱诊断比较,结果准确可靠,为推动TIG焊在线温度检测研究提供方法支持。

Argon is used as a protective gas in TIG welding,and abundant low-valent argon ions and linear spectra produced by argon atoms can be detected in welding arc.When the spark melts the metal in the welding process,plasma activates argon shielding gas to generate radiation.Argon does not react with the metal elements in the plasma under high temperature environment,and can isolate the elements in the ambient gas,so that the spectral structure generated in the welding process can accurately refl ect the temperature characteristics of the welding process.Therefore,in the application of online temperature detection in the welding process of TIG welding,the analysis of argon spectrum information should be the key research content.Using pure argon as protection gas,TIG welding is used to generate arc light radiation under diff erent welding current conditions;CCD spectrometer is used to collect spectral intensity data from 400nm to 900nm,and the wavelength and radiation parameters are identifi ed and calibrated by referring to NIST spectral database;spectral information analysis and mining method is used to select spectral line groups.The arc temperature of TIG welding under certain welding parameters is diagnosed by the slope method of multispectral line.In this experience,two groups of arc spectra generated by diff erent currents are selected to diagnose the welding temperature.Through comparative analysis and comparison with the reported diagnoses of argon atom and iron atom spectra,the results are accurate and reliable,and provide method support for promoting the research of online temperature detection of TIG welding.