点蚀和缝隙腐蚀试验

Pitting and crevice corrosion can be challenging to detect and predict, so understanding the risk factors of corrosion and susceptibility of a material can help anticipate issues before they arise. im体育APP offers pitting and 腐蚀测试 for your stainless steel/alloys and metal products used in many industries, 包括 能源, 航空航天, 基础设施环境和工业. 

If a material exhibits holes or gaps on its surface, pitting or crevice corrosion may be the culprit. Pitting corrosion is characterized by small holes, and crevice corrosion occurs where two materials meet. 

Pitting can be one of the most dangerous types of corrosion. 这不是直截了当的预测, 可能发生得很快, 并且可能只产生局部腐蚀, with the vast majority of the surface remaining unaffected. 

Pitting 腐蚀测试 to ASTM G48 A, C and E test methods

im体育APP performs pitting 腐蚀测试 following ASTM G48 A at test temperature, 通常可达60°C. The test involves the exposure of the materials in a 6 wt % ferrite chloride solution for test durations of 72 hours (typically 24 hours). A variation of the ASTM G48-A test used for duplex stainless steels is the ASTM A923 method – C test. 

Critical Pitting Temperature (CPT) is the technique used to determine the temperature at which the material produces pitting. In CPT, specimens are exposed for 72-hour periods to increase temperatures incrementally. The temperature is increased until pitting is observed, which is recorded as the Critical Pitting Temperature (CPT). 

作为G48方法的替代方法, the onset of pitting can be determined using the electrochemical test method described in ASTM150. 用这种方法, 样品被偏振了。, and the temperature of the solution increased until the CPT is detected.

Crevice 腐蚀测试 to ASTM G48 B, D and F test methods

im体育APP performs crevice 腐蚀测试 in accordance with ASTM G48 B at the test temperature, 通常可达60°C. The test involves the exposure of the materials in a 6 wt % ferrite chloride solution for test durations of 72 hours (typically 24 hours). 

The temperature at which crevices initiate can be determined using a Critical Crevice Temperature (CCT) test method. 在ASTM G48中, there are two test methods; one for stainless steel (method – D) and one for nickel alloys (method – F). 使用有条件现金转移支付, specimens are exposed for 72 hour periods to increase temperatures incrementally until a crevice is observed.

Our in-depth knowledge of industry standards and 腐蚀测试 programs allow us to advise you on the most suitable test method for your materials. Choosing the correct test method is crucial to achieve positive test results first time right and avoid costly delays in your project schedules, 从而节省您的时间和金钱.