航空用小口径薄壁不锈钢无缝钢管缺陷分析及工艺改进

Defect Analysis and Process Improvement of Small Diameter Thin-Wall Stainless Steel Seamless Pipe for Aviation Applications

摘要:

为了提高航空用小口径薄壁不锈钢无缝钢管的质量，通过对1Cr18Ni9Ti不锈钢管的化学成分分析、显微组织观察、力学性能试验，并且结合生产工艺，对钢管超声波探伤内壁报警缺陷的性质及其产生原因进行了分析，并针对原因提出了工艺改进措施。结果表明：探伤报警钢管内壁微裂纹缺陷产生于氮化钛链状夹杂附近，钢管固溶处理不充分是导致内壁缺陷形成的主要原因，钢管中存在的链状氮化钛夹杂促进了内壁微裂纹缺陷的产生；通过调整固溶工艺以保证钢管充分固溶软化，可提高钢坯冶金质量；控制链状氮化钛夹杂含量级别，以减少钢管内壁微裂纹缺陷的产生，从而提高成品钢管超声波探伤合格率。

Abstract:

In order to improve the quality of small diameter thin wall stainless steel seamless pipes that used for aviation applications， the chemical compositions， microstructures and mechanical properties of 1Cr18Ni9Ti stainless steel pipe were analyzed in this study. The formation mechanisms of the defects in the inner wall were analyzed by ultrasonic testing method. Due to the inadequate solid solution treatment， the chain-like titanium nitride inclusions in steel tubes promoted the micro-crack defects in the inner wall. One of the possible solutions is adjusting the solutioning process to ensure that the steel pipe could fully solution. Another method is improving the metallurgical quality of billet. Thus， the contents of chain-like titanium nitride inclusions would significantly reduce. By following the above， the product rate of steel pipes would improve.