TP347HFG弯头晶间腐蚀敏感性的研究及评价

Research and Evaluation on the Intergranular Corrosion Susceptibility of TP347HFG Steel Elbow

研究了TP347HFG冷弯弯头固溶处理后的晶间腐蚀敏感性及评价方法.以无晶间腐蚀倾向的TP347HFG直管作为研究主体,利用箱式电阻炉,以整体热处理的方式,模拟不同变形量的TP347HFG弯头固溶处理后的晶粒尺寸,制备了晶粒度在2～8级之间的一系列试料,敏化后加工成晶间腐蚀试样,在硫酸—硫酸铜—铜屑沸腾水溶液中进行晶间腐蚀试验.试验结果表明：变形弯头固溶后的晶粒尺寸粗于等于直管原料;所有模拟试样经过固溶和敏化处理后均无晶间腐蚀倾向.得出了由无晶间腐蚀倾向的直管制造的弯头固溶后也无晶间腐蚀倾向的结论.

Intergranular corrosion susceptibility and evaluate method of TP347HFG steel cold-formed elbow has been investigated. TP347HFG straight tubes without intergranular corrosion susceptibility are whole heat-treated in box resistor-stove to produce specimens which have the same grain sizes with the elbow. A series of specimens with grain sizes of 2-8 grades have been produced to intergranular corrosion standard samples after sensitized heat treatment. The test is undergoing in the boiling solution of sulfuric acid-copper sulfate-copper scrap. Results show that the grain size of TP347HFG deformation elbow is coarser than crude materials of the straight tubes. There is no intergranular corrosion tendency of TP347HFG simulated samples with solution treatment and sensitized heat treatment. The re- sult shows that solution treatment elbow produced by straight tubes without intergranular corrosion tendency has no intergtanular corrosion tendency.