Quality Control of High-Temperature Solid Rocket Control Components

2009 ◽  
pp. 21-21-15
Author(s):  
Richard L. Ahearn
Keyword(s):  
Quality Control ◽  
High Temperature ◽  
Solid Rocket

Thickness Measurement of MCrAlY High-Temperature Coatings by Frequency Scanning Eddy Current Technique

1997 ◽  
Author(s):  
Giampiero Antonelli ◽  
Marco Ruzzier ◽  
Fiorenzo Necci
Keyword(s):  
Quality Control ◽  
High Temperature ◽  
Eddy Current ◽  
Coating Thickness ◽  
Gas Turbines ◽  
Plane Electromagnetic Wave ◽  
Vacuum Plasma Spray ◽  
Frequency Scanning ◽  
Current Technique ◽  
Electrical Conductivities

Nondestructive characterization of non-serviced high-temperature coatings can be considered one of the important factors to achieve a higher level of structural integrity of advanced gas turbines. The present paper describes an innovative eddy current technique especially developed for measuring the thickness of metallic (MCrAlY) coatings applied by vacuum plasma spray on Ni-base superalloys. Conventional eddy current techniques, well established for quality control of coating thickness, are not applicable in this case because of the low difference of electrical conductivities of conting and base materials, which is a consequence of their quite similar physical and chemical properties. The new technique employs fast frequency scanning of the electromagnetic field in the range 100 kHz – 10 MHz, corresponding to probing depths from 1 mm to 0.1 mm. Dedicated hardware has been developed, featuring high sensitivity, stability and harmonic rejection. Analysis of the measured data (i.e. probe impedance vs frequency), in order to estimate the relevant diagnostic parameters (coating thickness, coating and base metal electrical conductivities), is carried out on the basis of a theoretical model of interaction between a plane electromagnetic wave and test piece. The results of tests performed on a non-serviced first stage blade are reported and compared with reference destructive data. Reliability, accuracy and practical applicability of the method meets the requirements for in-shop quality control.

scholarly journals Influence of post weld heat treatment for weld joint of P355GH

2018 ◽  
Vol 247 ◽  
pp. 00038
Author(s):  
Sławomir Parzych ◽  
Rafał Dziurka
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Quality Control ◽  
High Temperature ◽  
Weld Joint ◽  
Post Weld Heat Treatment ◽  
Microstructure And Properties ◽  
Welding Method ◽  
Welding Procedure ◽  
Weld Heat

From steel designed to work under pressure and exposed to high temperature apart from the good weldability, good mechanical properties are required. The guidelines set by the regulations require post welding heat treatment above 35mm thick. An important factor affecting the microstructure and properties of the joint made of thick-walled elements is heat treatment after welding. All welding operations must be properly planned before performing welding work. Welding procedure specification (WPS) is a document describing these operations, it is essential for proper determining of basics in planning welding operations and quality control in welding. The purpose of this paper is to compare the properties of joints made by 121 welding method in combination with and without post welding heat treatment.

Material’s Volumetric-Flow Rate (MVR) as a Unification Parameter in Asphalt Rheology and Quality Control / Quality Assurance Tool for High Temperature Performance Grading

2000 ◽  
Vol 10 (6) ◽  
pp. 288-306 ◽  
Author(s):  
Aroon Shenoy
Keyword(s):  
Quality Control ◽  
Quality Assurance ◽  
High Temperature ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Rheological Parameters ◽  
Dynamic Data ◽  
Control Quality ◽  
Temperature Performance ◽  
Asphalt Mastics

Abstract Rheological data of unmodified and polymer-modified asphalts are conventionally obtained from dynamic mechanical characterization and expressed in terms of sets of curves showing the variation of viscoelastic properties with frequency. Using the conventional melt flow indexer, the material’s volumetric-flow rate MVR (in cm3 / 10 minutes) through a predefined die under conditions of constant temperature and stress when obtained for the same asphalts, shows a direct relationship with the dynamic data. The MVR value helps in unifying the sets of dynamic data curves of |G*|, G” and |G* |/sin δ versus frequency in the case of unmodified asphalts, polymer-modified asphalts and asphalt mastics. The unification technique has a sound theoretical basis and the unified curves have far-reaching implications. Since MVR is so simple to determine quite accurately on a relatively inexpensive, easy-to-use flow measurement device (FMD), this parameter can be generated on paving sites or at refineries, if needed, rather than in research laboratories as is the case with the fundamental rheological parameters. The MVR can then be used as an excellent indicator of the fundamental rheological parameters through the use of the unified curves. The MVR can be utilized to accurately determine the currently used high temperature performance grade specification of paving asphalt. On account of the simplicity in obtaining this specification value from the MVR, it may be routinely used for quality control / quality assurance purposes. It can also be used as a rapid product development / formulation tool.

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