A Study on the Failure of AISI 304 Stainless Steel Tubes in a Gas Heater Unit

被引：21

作者：

Bahrami, Abbas ^{[1
]}

Taheri, Peyman ^{[2
]}

机构：

[1] Isfahan Univ Technol, Dept Mat Engn, Esfahan 8415683111, Iran

[2] Delft Univ Technol, Dept Mat Sci & Engn, Mekelweg 2, NL-2628 CD Delft, Netherlands

来源：

METALS | 2019年 / 9卷 / 09期

关键词：

convection tubes; AISI 304 stainless steel; failure analysis; sensitization; MICROSTRUCTURE;

D O I：

10.3390/met9090969

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

This paper investigates a failure in convection section tubes of a gas heater unit in a petrochemical plant. Tubes are made of AISI 304 stainless steel. The failure is reported after 5 years of service at working temperature 500 degrees C. The failure is in the form of circumferential cracks in the vicinity of the weld. Various characterization techniques, including optical and electron microscopes as well as energy-dispersive X-ray spectroscopy (EDS), were used to study the failure. Results showed that that the damage has initiated in the heat affected zone (HAZ) area parallel to the weld/base metal interface. Cracks have propagated alongside grain boundaries, resulting in an intergranular fracture. The main cause of failure was concluded to be attributable to the grain boundary sensitization and intergranular grain boundary attack due to improper welding and long time exposure of tubes to high temperature. Possible mitigation strategies to minimize similar failures will be discussed.

引用

页数：7

共 18 条

[1] High operating steam pressure and localized overheating of a primary superheater tube [J].