Critical Gap Corrosion Temperature Detection Of Nickel Based Chromium Containing Alloys

Applicable materials: Suitable for various nickel based chromium containing alloys, including typical grades such as Hastelloy, Inconel, Incoloy, etc., including nickel chromium molybdenum corrosion-resistant alloys, nickel chromium iron high-temperature alloys, and nickel based superalloys.

Applicable objects: including nickel based chromium containing alloy plates, rods, pipes, forgings, welded joints, equipment cylinders, pipelines, flanges, valves, and various corrosion-resistant components serving in chloride environments.

Applicable scenarios: Suitable for evaluating the minimum temperature (critical crevice corrosion temperature CCT) at which nickel based chromium containing alloys undergo crevice corrosion in oxidizing chloride environments (such as ferric chloride solution), used for material selection, quality control, service safety evaluation, and local corrosion resistance grading.

Detection purpose: Used to determine the threshold of crevice corrosion sensitivity of nickel based chromium containing alloys in chloride media, providing key data support for equipment design, material selection, and service life prediction in high-temperature chloride environments.

Critical crevice corrosion temperature (CCT) determination: Determine the minimum temperature at which a crevice corrosion of at least 0.025mm deep appears on the surface of the sample crevice under specified test conditions (usually a 6% ferric chloride solution with a pH value of 1.0-1.6) using the step heating method or constant temperature water bath method, ignoring edge corrosion.

Analysis of crevice corrosion morphology: Macroscopically observe the location and distribution characteristics of crevice corrosion, microscopically detect the depth, propagation path, and composition of corrosion products, and evaluate the severity of corrosion.

Classification of crevice corrosion sensitivity: Based on the critical crevice corrosion temperature value, the crevice corrosion resistance of nickel based chromium containing alloys is classified and sorted, providing a basis for material comparison and selection.

Special testing of welded joints: Focus on testing the critical crevice corrosion temperature of welds and heat affected zones, and evaluate the impact of welding processes on the material's resistance to crevice corrosion.

Corrosion product analysis: Determine the composition of corrosion products through chemical analysis or microstructure analysis, and assist in determining the mechanism of crevice corrosion.