Imaging of modified 9Cr–1Mo ferritic steel weldment via ultrasonic velocity measurements

Abstract

Ultrasonic velocity measurements have been carried out across the weld line in two perpendicular sections of modified 9Cr–1Mo ferritic steel weldments, in the as welded and post-weld heat treated (PWHT) conditions. The ultrasonic velocity plot is correlated with the weld profile in both the sections and with the associated microstructural features in different regions of the weldments for the two conditions investigated. The present study reveals that the weld profile can be imaged and the adequacy of the PWHT can also be assessed in modified 9Cr–1Mo ferritic steel weldments using ultrasonic velocity measurements.

Multipass pulsed current gas metal arc welding of P91 steel

“…The creep strength enhanced ferritic steels contain 9-12%Cr, small amounts of Mo, V, and Nb, and varying additions of W, Co, B, N, and Ni. [1][2][3] The modified 9Cr-1Mo grade steel that is referred to as P91 steel belongs to the family of creep strength enhanced ferritic steel and is a promising material for high temperature piping components in modern power plants. [1][2][3][4][5][6][7] However, the weldability of P91 steel is a major concern due to the loss of alloying elements, degradation of weld joint mechanical properties, its susceptibility to type IV cracking [1][2][3][4][5][6]8,9 and the formation of delta ferrite.…”

“…[1][2][3] The modified 9Cr-1Mo grade steel that is referred to as P91 steel belongs to the family of creep strength enhanced ferritic steel and is a promising material for high temperature piping components in modern power plants. [1][2][3][4][5][6][7] However, the weldability of P91 steel is a major concern due to the loss of alloying elements, degradation of weld joint mechanical properties, its susceptibility to type IV cracking [1][2][3][4][5][6]8,9 and the formation of delta ferrite. 5,[10][11][12][13] A careful control of the heat input per unit length and suitable choice of welding procedure, technique and post-weld heat treatment (PWHT) cycles are reported to minimise some of these problems.…”

Ultrasonics: A Technique of Material Characterization

“…The low intensity and high frequency ultrasonic waves are applied for medical diagnosis, acoustical holography, material characterization etc. The low intensity ultrasoud measurements provides a good diagnosis of material property and process control in industrial apllication (Alers, 1965;Green,1973;Lowrance, 1975;Renolds, 1978;Teagle, 1983;Smith, 1987;Varry, 1987;Thompson,1996;Jayakumar, 1998;Kumar, 2001;Raj, 2003;Roth, 2003;Blodgett, 2005).…”