电压对Q235钢等离子体电解硼碳共渗中光谱特性的影响

Influence of voltage on spectroscopic properties of Q235 steel during plasma electrolytic borocarburizing

采用液相等离子体电解渗方法,在280 V和300 V电压下对Q235低碳钢进行硼碳共渗处理,分析了渗层的显微组织和相成分。研究不同电压下硼碳共渗过程的光发射谱（OES）,并评估了等离子体放电区的电子温度、电子浓度特征参数。结果表明,等离子体电解硼碳共渗中放电区的电子浓度大于8×10^22m^-3,达到局部热平衡状态。电子温度为3000-12000 K,等离子体放电为活性碳原子和硼原子在钢基体中快速扩散创造了高温环境。随着电压的升高,等离子体放电变得剧烈,电子温度明显增加,Q235低碳钢表面岛状硼化物颗粒逐渐增大相连接,形成较厚的渗硼层。

A borocarburizing layer was prepared on Q235 low-carbon steel surface by liquid phase plasma electrolytic borocarburizing（PEB/C） at 280 V and 300 V,and microstructure and phase composition of the PEB/C hardening layer were analyzed.Optical emission spectroscopy（OES） of the PEB / C process under different voltage was investigated,and plasma parameters such as electron temperature and electron density were evaluated.The results show that the electron density in the discharge zone during plasma electrolytic borocarburizing is over 8 × 1022m-3,which means that the plasma discharge zone can meet a local thermal equilibrium state.Furthermore,the electron temperature is about 3000 K-12000 K,thus the plasma discharge provides a high temperature environment to enhance the rapid diffusion of active carbon and boron species into the steel.With increasing voltage,the plasma discharge around the steel specimen in the electrolyte becomes intense and the electron temperature in the plasma zone increases.Under low voltage,only some separated island-like boride particles are formed on the steel surface,then they gradually grow to form a boride layer with increasing voltage.