Gang YU
,
Xueyuan ZHANG
,
Yuanlong DU
材料科学技术（英）
The principle, construction and application of two types of electrochemical sensors-amperometric and potentiometric are surveyed. Both types of sensors are very sensitive to changes in temperature. The accuracy of hydrogen measurement depends on both the precision of sensors developed and the reliable technique of installation and security of sensors. The two types of sensors have been used for in-situ determining hydrogen permeated in steels owing to a corrosive reaction, a hydrogen gas circumstance at elevated temperatures and high pressure or also a pretreatment process such as pickling and plating process, etc.
关键词:
Gang YU
,
Xueyuan ZHANG
,
Yuanlong DU
材料科学技术（英）
Based on the electrochemical permeation technique and the patent by Du, an intelligent electrochemical measurement system for determination of the hydrogen distribution in the wall of hydrogenation reactor has been developed and tested. It consists of a PC computer, a single chip unit, an I/V converter and an electrochemical hydrogen probe. The construction of the electrochemical hydrogen probe is described and the features of the measured system are given. The diffusion coefficient of 2.25Cr1Mo steel determined with present system was in good agreement with the value in the literature. Experimental results of hydrogen concentration in a wall of hydrogen charged testing autoclave made of AISI 321 stainless steel are presented. The present system can intelligently display hydrogen amount-of-substance concentration and mass fraction concentration, hydrogen concentration distribution curves in steels, permeation current density curve. An intelligent detection technique can be provided for predicting the susceptibility to hydrogen-induced cracks owing to hydrogen permeation in the wall of hydrogenation reactor in the field.
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