1、 - - STD-AWS TSM-ENGL 07842b5 0514157 OLb Thermal Spray Manual A practical reference guide Located and reviewed by the AWS Product Development Committee as a service for quality-minded welding fabricators. Acknowledgment This Thermal Spray Manual was a project of The National Shipbuilcing Research P
2、rogram for the Society of Naval Architects and Marine Engineers Ship Production Committee Welding Panel SP-7. It was prepared in 1996 by Puget Sound Naval Shipyards Welding Engineering entity. IC is the final report of Task 7-92-3 of contract N00167-90H-0057 engaged by the Maritime ACmFnistration of
3、 the U.S. Department of Transportation with support from the U.S. Navy. Note This publication is designed to provide information in regard to the subject matter covered. It is made available with the understanding chat the publisher is not engaged in the rendering of professional advice. Reliance up
4、on the information contained in this document should not be undertaken without an independent verification of its application for a particular use. The publisher is not responsible for loss or damage resulcing from use of this publication. This docurent is not a conselsus standard. Users should refe
5、r to the appliccbic standards for their particular application. STD.AWS TSM-ENGL m OJBLZS OSIALU TSZ = CONTENTS i. 2. 3. 4. 5. 6. 7. 8. 9. 18. 11. l2. “TIX PAGES a ceramic used in powder or rod form in thermal spraying operations. May also be a blasting medium. ANCHOR-TOOTH PROFILE: The condition of
6、 the substrate after abrasive blasting for surface roughening. ARC WIRE PROCESS: A thermal spray process where a heating zone is created by an arc between two continuously fed metallic wires, one positively charged and one negatively charged. The heating zone melts the wire material and compressed a
7、ir or an inert gas is used to propelled the molten material to the substrate. ARC: A luminous discharge of electrical current crossing the gap between two electrodes. ARGON: An inert gas that can be used in plasma powder thermal spray process. BASE MATERIAL: The material of the component being therm
8、al sprayed. BLASTING: A method of cleaning or surface roughening by a forcibly projected stream of sharp angular abrasive. BOND COAT: A preliminary (or prime coat) of material that improves adherence of the subsequent spray deposit. BOND STRENGTH: The force required to pull a coating free of a subst
9、rate, usually expressed in psi Va). CARRIER GAS: The gas used to carry powdered material from the powder feeder or hopper to the thermal spray gun. CERAMICS: Various hard, brittle, heat and corrosion-resistance materials normally used as the fina1 coat with the thermal spray process. CERMET: A physi
10、cal mixture of ceramics and metais; examples are alumina plus nickel and zirconia plus nickel. I 2JGLSSARY STD-AUS TSM-ENGL 0764265 05L4Lbt 483 COATING SYSTEM: One or more thermal spray coatings that are qualified for use singly or in combination. An example of a one coating system is a stainless st
11、eel coating applied for restoration of dimensions. An example of a two coating system is a nickel base bond coat and ceramic final coat. - COATING STRESS: The stresses in a coating resulting from rapid cooling of molten material or semimolten particles as they impact the substrate. Coating stresses
12、are a combination of body and textural stresses. COATING: (1) The act of building a deposit on a substrate, (2) the spray deposit. COEFFICIENT OF THERMAL EXPANSION: The ntio of the change in length per degree rise in temperature to the length at a standard temperature such as 68F (20C). COMPOSITE: E
13、ach grain contains all chemical elements present in the powder, but they are not alloyed. DEFECT: A discontinuity or group of discontinuities that by natiire or accumulated effect (for example, total crack length) render a part or product unable to meet minimum applicable acceptance standards or spe
14、cification. This term designates rejectability . FINAL COAT: The last coating to be applied during the thermal spraying sequence. FIXTURING: Mechanical positioning to support the machinery component and thermal spray gun. FLAME WIRE PROCESS: A thermal spray process that uses an oxygen fuel flame to
15、create a heating zone. A wire is then continuously fed into the heating zone where is melted and atomized and then propelled to the substrate by the force of the burning gasses and compressed air. FLAME POWDER PROCESS: A thermal spray process that uses an oxygen fuel flame to create a heating zone.
16、Powder is fed into the heating zone and melted. The molten material is then propelled to the substrate by the force of the burning gasses and compressed air. FREITING: Surface damage resulting from relative motion between surfaces in contact under pressure. GRIT BLASTING: See Blasting. HELIUM: An in
17、ert gas that can be used in the plasma powder thermal spray process. HIGH VELOCITY OXYGEN FUEL PROCESS: A thermal spray process where oxygen and fuel are mixed at high pressures. This mixture is ejected from a nozzle and ignited. Into the high velocity flame powder is injected. The powder is propell
18、ed to the substrate by the force of the burning gases. When the thermal spray matenai collide with the substrate it plasticizes and forms a coating. STD.AWS TSM-ENGL I 07842b5 05L4Lb3 3LT = THERMAL SPRAY MANUAU3 HYDROGEN: A fuel gas that can be used with plasma powder and high velocity oxygen fuel t
19、hexmai spray processes. INERT GAS: A gas which does not normally combine chemically with the substrate or the deposit. INTERFACE: The contact surface between the spray deposit and the substrate and between the bond coat and fma coat. INTERPASS TEMPERATURE: In muItiple pass thermal spraying, the temp
20、erature (minimum or maximum as specifled) of the deposited thermal spray coating before a subsequent pass is started. MASKING: The method of protecting the areas adjacent to the area to be abrasive blasted and thermal sprayed. MECHANICAL BOND: The principal bond that holds thermal spray materials to
21、gether and is formed between base metais and fder metals in all processes. METALLIZING: See preferred term “thermal spraying“. MICROMETER: Any device for measuring minute distances, especially one based on the rotation of a finely threaded screw. MUST: The word “must“ is to be understood as mandator
22、y for the purpose of avoiding coating failures. * NITROGEN: An almost inert gas that can be used with the plasma powder process. N0N“SFERRED ARC: An arc established between the electrode and the constricting nozzle. The workpiece is not in the electrical circuit. NOZZLE: (1) A device which directs s
23、hielding media, (2) a device that atomizes air in an arc wire spray gun, (3) the anode in a plasma gun, (4) the gas burning jet in a powder, rod, or wire flame spray gun. OMDES: A binary compound of an element or radical with oxygen. QXYGEN: A gas that is used with the flame wire, flame powder, and
24、high velocity oxygen fuel thermal spray processes. PARAMETER: A measurable factor relating to severa1 variables; loosely used to mean spraying variable, spraying condition, spraying distance, angle gas pressure, gas flow, etc. PASS: A single progression of the thermal spray device across the surface
25、 of the substrate. 7 4IGLOSSARY PLASMA POWDER PROCESS: A thermal spray process where a heating zone is created by an arc between a tungsten electrode and a nozzle. A gas or gas mixture is passed through this arc. This gas or gas mixture then exits the nozzle, forcing the flame outside the gun. A pow
26、der is fed into the flame where it is melted and propelled to the substrate by the force of the gas or gas mixture. POROSITY: Cavity type discontinuities withm a thermal sprayed coating. PREHEAT: Heat applied to the substrate prior to thermal spraying. This may be performed to remove moisture and/or
27、 to reduce residual stresses. PRIMARY GAS : The major constituent of the arc gas fed to the gun to produce the plasma; usually argon or nitrogen. PROCEDURE: The detailed elements of a process or method used to produce a specific result. PYROMETER: An electrical thermometer for measuring high tempera
28、tures. QUALITY ASSURANCE (OA): The activity of providing to aii concerned the evidence needed to establish confidence that the quality function is being performed adequately (from the Juran Quaiity Control Handbook, 3rd edition). SEALER: Material applied to thermal sprayed coatings to close pores an
29、d facilitate finishing. SECONDARY GAS: The minor or second constituent of the arc gas fed to the gun to produce plasma. SHADOW MASKING: A protective device that partially shields from a small distance above the work, thus permitting some overspray to produce a feathering at the coating edge. SHOULD:
30、 The word “should“ is to be understood as advisory for the purposes of improving coating quality and/or increasing the efficiency of the operation. SHOULDER: Area of component at the end of the undercut. SOLVENT CLEANING: component that is to be thermal sprayed. A method used to remove contaminants
31、from the machinery SPALLING: The flaking or separation of a thermally sprayed coating. SPLAT: A single thin flattened sprayed particle. - SPRAY ANGLE: substrate to the axis of the spraying nozzle. The angle of particle impingement, measured from the surface of the SPRAY DISTANCE: The distance mainta
32、ined between the thermal spraying gun nozzle tip and the surface of the component during spraying. STDmAWS TSM-ENGL W 0784265 05141b5 192 D THERMAL SPRAY MANuAL/s SPRAY RATE: The rate at which surfacing material passes through the thermal spray gun. SUBSTRATE: Any material to which a thermally spray
33、ed coating is applied. SURFACE PREPARATION: The operation necessary to produce a desired or specified surface condition. SURFACE FEET PER MLNUTE: The circumferential velocity of the substrate. TENSILE BOND STRENGTH: See preferred term, “bond strength. I THERMAL SPRAYING: A group of processes where f
34、inely divided metallic or non-metallic materials are deposited in a molten or semi-molten condition to form a coating. THEMAL SPRAY GUN: A device for heating, feeding and directing the flow of a surfacing material. TRAVERSE SPEED: The hear velocity at which the thermal spray gun traverses across the
35、 substrate during the spraying operation. TSJCR: Thermal Spray Job Control Record. TURNING FXTuRE: Mechanized equipment (Le. lathe and traversing gun mount) that keeps the gun to-substrate distance and spray angle fixed during spraying and the relative movement between the gun and substrate accurate
36、ly controlled. UNDERCUTTIN G: A step in the sequence of surface preparation involving the removal of substrate material. WORKPIECE: The object or surface to be coated. See preferred term substrate. * Although guideIines using the word “must“ can generally be shown to have exceptions, the experience
37、of the authors has been that any exceptions are so minor in nature or frequency that they should be disregarded. (See definition of “should“). * Definitions of Thermal Spray terms can be found in the American Welding Societys Thermal Spraying Manual “Practice, Theory, and Application“. INTRODUCTION
38、This themal spray manual is intended to be a working manual for its user. The user is expected to add and remove infomation as appropriate based on the users needs. This document provides fundamental information for a variety of intended users, such as: * DESIGN ENGINEERS * THERMAL SPRAY ENGINEERS *
39、 PRODUCTION SHOP SUPERVISORS * JOURNEYMAN THERMAL SPRAY OPERATORS * SHOP PLANNERS * MACHINIST The pupse of this manual is to provide fundamentals and to assist in the use of the thernial spray processes in the refurbishment of shipboard machinery components by aiding individuals in: * THE SELECTION
40、OF APPROPRIATE APPLICATIONS * “NG METHODS * APPROPRIATE COATING SELECTIONS * METHODS OF PROCEDURE QUALIFICATION * SELECTION OF THERMAL SPRAY PROCESSES * MASKING TECHNIQUES * SURFACE PREPARATION TECHNIQUES * SPRAYING TECHNIQUES * ASSOCIATED MACHINING TECHNIQUES To aid individuals in making sound ther
41、mal spray decisions, applicable basic information is contained within various section of this manual. It is the intent of this manual to provide some fundamental structure to be able to find basic information easily and to build upon it. Fundamental information about thermal spraying, coatings, proc
42、edure and operator qualification, coating selection, and applications is contained in this manual. From a thermal spray engineering stand point, this manual is intended to aid designers in making the best decisions as to repair applications, and coating system selections. STD-AWS TSM-ENGL W 07842b5
43、05i4Lb7 Tb5 W INTRODUCTION This manual is designed to be a guide in preforming daily tasks, as a training aid, and as a foundation for building a sound thermal spray program and developing a dedicated staff with knowledgeable personnel. STD-AWS TSM-ENGL = 07842b5 05L4Lb8 9TL REFERENCES - 1. 2. 3. 4.
44、 5. 6. 7. 8, 9. 1 o. 11. 12. 13. 14. A Plasma Flame Spray Handbook: March 1977, Naval Ordnance Station Louisville, Kentucky Design and Planning Manual: Puget Sound Naval Shipyard Brernerton, Washington Thermal Spraying “Practice, Theory, and Application “: 1 995 American Welding Society, Miami, Flor
45、ida Recommended Safe Practices for Thermal Spraying: AWS C2.1 AWS (etc) Crawford, i., The Cost Effectiveness of Flame Spray Coating for Shipboard Corrosion Control: Nation Shipbuilding Research Program #O31 3, July 1990 Ingham, H., Shepard, A., Plasma Flame Process; Flame Spray Handbook, Volume 111,
46、 Metco Inc., Wesbury, New York Thermal Spray Processes For Naval Ship Machinery Application MIL-STD- 1687: February 1987, Department Of The Navy, Naval Sea Systems Command, Washington, DC Metal Sprayed Coatings For Corrosion Protection Aboard Naval Ships MIL- STD-2138: May, 1992, Department Of The N
47、avy, Naval Sea Systems Command, Washington, DC Thermal-Spra y Machinery Applications from Selected Industrial and Navy Sources: May, 1985, Integrated Systems Analysts, Inc. Process lnstructon - MERRIIMA) - Powder Flame Spray Process: October, 1992, Department Of The Navy, Naval Sea Systems Command,
48、Washington, DC Thermal Sprayed Valve Sterns “Final Report “: September, 1 991, Puget Sound Naval Shipyard, Bremerton, Washington Program Plan For Application Machinery Repair: August, 1988, Puget Sound Naval Shipyard. 1 6. Uniform lndustrial Process instruction 0074-902, Thermal Spray; Corrosion Con
49、trol: February, 1991, Puget Sound Naval Shipyard. 1 7. Procedure Handbook for Shipboard Thermal Sprayed Coating Applications: March, 1992, UNITED STATES NAVY, David Taylor Research Center, in cooperation with National Steel and Shipbuilding Company, San Diego, California. STD.AWS TSM-ENGL 0784265 0514171 49b FUNDAMENTALS OF THERMAL SPRAYING PREPARED BY: PUGET SOUND NAVAL SHIPYARD STDmAWS TSM-ENGL 0784265 0534 a. Base Material Type U. C. Service Environment d. e. Ftiriction of Area to he Repaid Theniial Spray Coating Material Availa
