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Title: Spray shadowing for stress relief and mechanical locking in thick protective coatings

Abstract

A method for applying a protective coating on an article, comprising the following steps: selecting an article with a surface for applying a coating thickness; creating undercut grooves on the article, where the grooves depend beneath the surface to a bottom portion with the grooves having an upper width on the surface and a lower width on the bottom portion connected by side walls, where at least one of the side walls connects the upper width and the lower width to form an undercut angle with the surface less than 90.degree.; and, applying the protective coating onto the article to fill the undercut grooves and cover the surface, thereby forming weak paths within the protective coating.

Inventors:
 [1];  [1]
  1. Los Alamos, NM
Publication Date:
Research Org.:
Los Alamos National Laboratory (LANL), Los Alamos, NM
Sponsoring Org.:
USDOE
OSTI Identifier:
909414
Patent Number(s):
7,220,458
Application Number:
11/140,661
Assignee:
Los Alamos National Security, LLC (Los Alamos, NM) ALO
DOE Contract Number:
W-7405-ENG-36
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING

Citation Formats

Hollis, Kendall, and Bartram, Brian. Spray shadowing for stress relief and mechanical locking in thick protective coatings. United States: N. p., 2007. Web.
Hollis, Kendall, & Bartram, Brian. Spray shadowing for stress relief and mechanical locking in thick protective coatings. United States.
Hollis, Kendall, and Bartram, Brian. Tue . "Spray shadowing for stress relief and mechanical locking in thick protective coatings". United States. doi:. https://www.osti.gov/servlets/purl/909414.
@article{osti_909414,
title = {Spray shadowing for stress relief and mechanical locking in thick protective coatings},
author = {Hollis, Kendall and Bartram, Brian},
abstractNote = {A method for applying a protective coating on an article, comprising the following steps: selecting an article with a surface for applying a coating thickness; creating undercut grooves on the article, where the grooves depend beneath the surface to a bottom portion with the grooves having an upper width on the surface and a lower width on the bottom portion connected by side walls, where at least one of the side walls connects the upper width and the lower width to form an undercut angle with the surface less than 90.degree.; and, applying the protective coating onto the article to fill the undercut grooves and cover the surface, thereby forming weak paths within the protective coating.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue May 22 00:00:00 EDT 2007},
month = {Tue May 22 00:00:00 EDT 2007}
}

Patent:

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  • Translated from Probl. Procbosti; 5: No. 3, 90-94(Mar 1973). Results of the investigations show that under conditions of brief static loading molybdenum sheet of grade MCh-II is almost insensitive to siress concentrations (for the selected types of concentrators). The presence of a diffusion protective coating leads to a considerable decrease in the ductility of the material over the whole investigated range of temperatures and to a decrease in its strength at temperatures below the coating deposition temperature. It was established that the strength of specimens with protective coatings in the presence of stress concentrators is higher than the strength ofmore » smooth specimens with the same coatings. (auth)« less
  • A cooling system is described of the pressurized water type for a nuclear reactor including: a reactor pressure vessel; primary liquid coolant circulation loops for the reactor pressure vessel with the loops being in communication within the reactor pressure vessel to form a closed primary reactor cooling system, and with each loop including a hot leg and a cold leg leading respectively from and to the reactor pressure vessel, a steam generator having its input connected to the respective hot leg and its output connected to the respective cold leg, and a coolant pump connected in the respective cold leg;more » a vertical pressurizer vessel which is partially filled with liquid coolant; a coolant connection from the lower end of the pressurizer vessel to the hot leg of one of the loops; a heater for heating the liquid coolant in the lower portion of the pressurizer vessel so as to produce a pressure in the upper portion of the pressurizer vessel, and hence in the primary cooling system, such that the coolant in the system does not boil; and means, connected to the upper end of the pressurizer vessel, for reducing the pressure in the pressure vessel; the improvement wherein the means for reducing the pressure in the pressurizer vessel comprises: a coolant spray nozzle in the upper end of the pressurizer vessel. A closed coolant tank is disposed vertically above the pressurizer vessel and contains liquid coolant which is subcooled at the pressure within the primary cooling system; a pressure outlet in the upper end of the pressurizer vessel; first and second coolant connections for the coolant tank, with the first coolant connection being at the bottom of the tank and the second coolant connection being near the top of the tank; and pressure responsive valve means, responsive to the pressure in the pressurizer vessel reaching a predetermined value, for connecting the first and second coolant connections to the nozzle and to the pressure outlet, respectively.« less
  • Stress-relief annealing (SR treatment) is often applied to relieve welding residual stresses in the fabrication process of pressure vessels, etc. This study aims at development of an efficient method as simple as hand calculation to estimate reduction of residual stresses of very thick welded joint by SR treatment. In the first report, an estimating method was developed for relaxation tests, in uniaxial stress state, at changing and constant temperatures because the stress relaxation phenomenon is considerably similar to that observed in the SR treatment of a joint. In this report, the stresses relaxed by SR treatment in a very thickmore » welded joint are analyzed accurately by the finite element method based on thermal elastic-plastic-creep theory. The characteristics of the changes of the welding residual stresses in multiaxial stress state are studied in detail for further development of the estimating method to SR treatment of a very thick welded joint, of which the stress state and boundary condition are very complex.« less