Effect of fabrication procedure and metal quality of pipes formed from chromium-magnesium steel on their service properties

Abstract

This paper examines the effect of fabrication procedure and metal quality on the service properties of pipes fashioned from chromium-magnesium steel DI59. The kinetics of the development of creep strain of the metal in the temperature region from 650 to 730°C is investigated. It is indicated that vigorous strain begins to develop after 90% of the expected life has been exhausted. It is established that in the steel under investigation, the content of ó-phase over the entire period corresponding to 30 -90% exhaustion of expected life varies negligibly from 1.8 to 2.5%, and cannot be a criterion for estimation of exhaustion of the metal's expected life. The investigations that we conducted on steel DI59 tubes fabricated in accordance with a new procedure indicated a significant increase in the long-term ductility of the steel, which dictates the high quality of the metal.Keywords: quality and expected life of metal, steel DI59, service properties, tubes, metal strain, ductility of steel.

Decoupled Monitoring Method for Strain and Cracks Based on Multilayer Patch Antenna Sensor

“…Traditional metal structure health monitoring methods mainly use either a single sensor or a combination of sensors (including metal strain gauges, piezoelectric acceleration sensors [ 3 , 4 ], various optical fiber sensors [ 5 , 6 ] and acoustic emission sensors [ 7 , 8 , 9 ]) for strain testing, vibration testing, crack identification, and crack growth monitoring of these structures. To perform structural health monitoring under complex working conditions, the single testing functions of traditional sensors mean that large numbers of sensor nodes are usually arranged to form a sensor network, which can present some problems in practical use, including wiring difficulty, high installation costs, complex structures, and low efficiency.…”