液氨球罐应力腐蚀开裂的诊断

Diagnostic Technique to Prevent a Liquid Ammonia Sphere from Stress Corrosion Cracking

一台由日本工业标准JIS-SPV36钢制造、直径21.5m、容积5200m^3的大型液氨球罐,由于应力腐蚀开裂,其安全性受到严重威胁.本研究针对该球罐裂纹特征和腐蚀产物进行分析,并估算结构的可靠度;在大量现场实测和试件试验数据统计分析的基础上,提出了防止产生应力腐蚀裂纹的诊断方法,并已于1986年12月该球罐年度大修时实施.

Stress corrosion crack ing (SCC) was seriously imperilling the safety of a Japanese Industrial Standard JIS-SPV36 steel ammonia sphere of volume 5200 m3 and diameter 21.5m. Chemical composition of the corrosion products has been analyzed, a survey of the stress corrosion cracks propagation characteristics at welded joints has been made, and statistical analysis of the results based on the record of internal inspection of the sphere in open status and of experimantal studies have been worked out. Then the reliability of the sphere wasevaluated. An approach Spray metal coating to prevent the ammonia sphere from SCC has been proposed. Spray coating on the internal surface of the sphere during the period of annual regularmaintenance in December 1986 has proven to be effective on practical trial.