An experimental and numerical analysis of hydrogen assisted cracking and weldability test methodology. Ph.D. Thesis

Dighde, R M

Title: An experimental and numerical analysis of hydrogen assisted cracking and weldability test methodology. Ph.D. Thesis

Full Record
Other Related Research

Abstract

The preferred method for increasing resistance to hydrogen-assisted cracking (HAC) is the application of an adequate preheating temperature, T(sub ph). The suitability of given welding conditions, including T(sub ph), in avoiding HAC is generally assessed through the use of Tekken and Lehigh weldability restraint tests. The safe welding conditions determined from these tests are then applied in industrial fabrication. It is observed that these safe welding conditions do not always avoid HAC in actual weldments. Therefore, it is necessary to evaluate the weldability testing procedure in its entirety against the more general industrial fabrication practice and understand the inherent differences. The differences arising, at different stages of weldability testing procedure, from weld hydrogen measurement technique, weldability testing procedure, hydrogen diffusion behavior, residual stress development, and dimensional differences in weldability tests and actual weldments were analyzed in detail using an experimental and numerical approach. The weld hydrogen measurement results indicated that the existing hydrogen measurement standards do not measure the weld hydrogen levels in actual weldments, and should, therefore, be modified for use in weldability testing procedure. The Tekken and Lehigh weldability test results suggested that weld induced variation at stress concentration locations strongly influences the HAC tendency and crack propagationmore »« less

Authors:: Dighde, R M

Publication Date:: Fri Dec 31 00:00:00 EST 1993

Research Org.:: Oregon Graduate Inst. of Science and Technology, Beaverton, OR (United States)

OSTI Identifier:: 121793

Resource Type:: Miscellaneous

Resource Relation:: Other Information: TH: Ph.D. Thesis; PBD: 1993

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; WELDED JOINTS; HYDROGEN EMBRITTLEMENT; CRACK PROPAGATION; WELDABILITY; DIFFUSION; FINITE ELEMENT METHOD; HEAT TRANSFER

Citation Formats


                    Dighde, R M. An experimental and numerical analysis of hydrogen assisted cracking and weldability test methodology. Ph.D. Thesis.  United States: N. p., 1993. 
        Web.

Copy to clipboard


                    Dighde, R M. An experimental and numerical analysis of hydrogen assisted cracking and weldability test methodology. Ph.D. Thesis.  United States.

Copy to clipboard


                    Dighde, R M. 1993.  
        "An experimental and numerical analysis of hydrogen assisted cracking and weldability test methodology. Ph.D. Thesis".  United States.

Copy to clipboard


                    
@article{osti_121793,

  title        = {An experimental and numerical analysis of hydrogen assisted cracking and weldability test methodology. Ph.D. Thesis},

  author       = {Dighde, R M},

  abstractNote = {The preferred method for increasing resistance to hydrogen-assisted cracking (HAC) is the application of an adequate preheating temperature, T(sub ph). The suitability of given welding conditions, including T(sub ph), in avoiding HAC is generally assessed through the use of Tekken and Lehigh weldability restraint tests. The safe welding conditions determined from these tests are then applied in industrial fabrication. It is observed that these safe welding conditions do not always avoid HAC in actual weldments. Therefore, it is necessary to evaluate the weldability testing procedure in its entirety against the more general industrial fabrication practice and understand the inherent differences. The differences arising, at different stages of weldability testing procedure, from weld hydrogen measurement technique, weldability testing procedure, hydrogen diffusion behavior, residual stress development, and dimensional differences in weldability tests and actual weldments were analyzed in detail using an experimental and numerical approach. The weld hydrogen measurement results indicated that the existing hydrogen measurement standards do not measure the weld hydrogen levels in actual weldments, and should, therefore, be modified for use in weldability testing procedure. The Tekken and Lehigh weldability test results suggested that weld induced variation at stress concentration locations strongly influences the HAC tendency and crack propagation behavior. Finite element analysis (FEA) of hydrogen diffusion behavior in weldability tests and actual weld grooves indicated that hydrogen diffusion is a strong function of the groove shape and the weld thermal cycle, and hence, direct applicability of weldability test results to actual weldments can be misleading. Elasto-plastic thermo-mechanical behavior of Tekken and Lehigh weldability tests during welding was carried out using FEA.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/121793},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {Fri Dec 31 00:00:00 EST 1993},

  month        = {Fri Dec 31 00:00:00 EST 1993}

}

Copy to clipboard

Miscellaneous:

Other availability

Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that may hold this item.

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Weldability of an abrasion-resistant steel

Book Adonyi, Y; Domis, W; Chen, C

The welding performance of a low-carbon-equivalent, abrasion-resistant steel newly developed for the mining industry was studied using a combination of simulative and actual weldability tests. The susceptibility to hydrogen-induced cracking in the weld-metal and heat-affected zones (HAZ), as well as the potential loss of strength and toughness in the HAZ, were evaluated. Simulative testing included the use of the Gleeble 1500 thermomechanical simulator to produce single and multiple-pass weld HAZ microstructures on CVN-size specimens. The effects of heat input, interpass temperature, and post-weld heat treatment (PWHT) on the HAZ microstructure and properties were determined. Additionally, a computer software was usedmore »« less
Transformation, metallurgical response and behavior of the weld fusion zone and heat affected zone in Cr-Mo steels for fossil energy application: Final technical report for January 1985-September 1987

Technical Report Lundin, C; Henning, J; Menon, R; ...

This research program was undertaken to provide fundamental and basic metallurgical information on the behavior of the heat affected zone (HAZ) in Cr-Mo steel welds as well as practical information on their relative weldability. The principal work was the evaluation of the post weld heat treatment (PWHT) cracking of Cr-Mo steels ranging in Cr content from 2-1/4% to 9%. Differences in observed cracking behavior were contrasted with composition, on cooling transformation behavior and HAZ microstructure. Hydrogen assisted cracking (HAC) studies using a large scale cracking test were conducted on 2-1/4 Cr and 3 Cr steels. Soft zone studies were conductedmore »« less
Welding and weldability of directionally solidified single crystal nickel-base super-alloys

Technical Report vitek, j

The objective of this CRADA project was to investigate the weldability of polycrystalline, directionally-solidified, and single-crystal, nickel-base super-alloys. These materials are used extensively in turbine engine components. The ability to weld these materials is highly desirable in that it would greatly facilitate component fabrication. Welding of these materials would also have the potential benefit of allowing for the repair of cracked or worn components. Specifically, the program had four objectives: (1) to evaluate the weldability of nickel-base super-alloys; (2) to characterize the solidification microstructure of the welds; (3) to evaluate the phase stability of the weldments during exposure to servicemore »« less
https://doi.org/10.2172/11013

Full Text Available
Weldable high strength steels for naval construction

Book Healy, J; Billingham, J; Chubb, J; ...

The benefits of high strength steels in terms of enhanced mechanical performance and weight and cost reduction have been known for some time. However, these materials have not been widely used in industry. One of the main reasons behind this has undoubtedly been a lack of knowledge and experience with respect to their weldability. Moreover, traditional high strength steels, of the nickel chrome molybdenum type, are known to be difficult to weld, requiring expensive fabrication procedures to guarantee satisfactory production of crack-free welds. This paper presents data on weldability and weldment properties for a group of modern high strength steelsmore »« less
Weldability of HAYNES 282 alloy for new fabrications and after service exposure

Journal Article White, H; Santella, Michael; Specht, Eliot - Energy Materials: Materials Science & Engineering for Energy Systems

The effect of alloying elements on the mechanical properties and weldability of wrought gamma prime strengthened nickel based superalloys is well known. An understanding of the basic guidelines concerning alloying additions has led to the invention and development of HAYNES 282 alloy for applications in aircraft and land based gas turbines and other high performance high temperature environments. The alloy combines exceptional high temperature properties with good weldability and fabricability. At high temperatures (?900 >C), the alloy is stronger in creep strength than Waspaloy alloy (UNS N07001) and it approaches the creep strength of R-41 alloy (UNS N07041). Because themore »« less
https://doi.org/10.1179/174892310X12811032100114

Similar Records