1、Designation: E1306 11E1306 17Standard Practice forPreparation of Metal and Alloy Samples for ChemicalAnalysis by Electric Arc Remelting1This standard is issued under the fixed designation E1306; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the preparation of solid samples of reactive and refractory metals and al
3、loys by electric arc remelting.The samples for melting may be in the form of chips, turnings, wires, and sponge. Powdered metals need to be compacted beforemelting.sponge and powdered metals.1.1.1 This practice is also suitable for preparation of solid samples of other metals, such as steels, stainl
4、ess steels, tool steels,nickel, nickel alloys, cobalt, and cobalt alloys by electric arc remelting.alloys.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety an
5、d health practices and determine the applicability of regulatorylimitations prior to use. Specific hazard statements are given in Section 9.1.3 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principl
6、es for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials3. Termi
7、nology3.1 DefinitionsFor definitions of terms used in this practice, refer to Terminology E135.4. Summary of Practice4.1 Metal chips, turnings, or wires Various forms are melted into a button approximately 114 in.inches in diameter andapproximately 14-in. inches thick using an electric arc furnace.
8、The action of the arc creates agitation and mixing of the moltenmetal which produces a homogeneous sample.5. Significance and Use5.1 This sampling practice is useful for converting chips, turnings, and wires material taken from ingots or other solid materialsinto a homogeneous solid sample suitable
9、for direct excitation on an a spark atomic emission or X-ray fluorescence spectrometer.The resultant button may itself be chipped to provide specimens for test methods requiring solutions or chips.5.2 This practice has been used extensively for the preparation of zirconium, zirconium alloy, titanium
10、, and titanium alloymaterials, and is applicable to other reactive, refractory, ferrous and nonferrous alloys, such as cobalt, cobalt alloys, niobium,nickel, nickel alloys, steels, stainless steels, tantalum, tool steels, and tungsten.6. Interferences6.1 Test samples of known composition shall be us
11、ed to determine if there is any The user should carefully consider the impactof using remelted samples for analysis as remelted samples may be subject to selective volatilization or segregation of the impurity1 This practice is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for
12、 Metals, Ores, and Related Materials and is the direct responsibility ofSubcommittee E01.20 on Fundamental Practices.Current edition approved Nov. 1, 2011May 15, 2017. Published December 2011June 2017. Originally approved in 1989. Last previous edition approved in 20072011 asE1306 07.E1306 11. DOI:
13、10.1520/E1306-11.10.1520/E1306-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an AST
14、M standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In al
15、l cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1any elements. Elements known to volatilize are bismuth, cadmium, chlorine,
16、lead, magnesium, sodium, tellurium, thallium,uranium, and zinc. Other elements that may change in content are the interstitial gases, oxygen, nitrogen, and hydrogen, pluscarbon, which may be added due to the graphite anode. if a graphite anode is used. A tungsten anode may be substituted if carbonpi
17、ckup is a concern. Tungsten contamination may occur if this electrode is used. Copper contamination also may be introducedfrom the melting crucible.7. Apparatus7.1 Electric Arc RemeltRemit FurnaceThis section describes the various components of an electric arc remelt furnace. Referto Fig. 1 to see h
18、ow each component is arranged. The number assigned to each component in the following description correspondsto the number in the schematic.7.1.1 Water-Cooled Upper Housing (1), approximately 6-in. 6 inches in diameter and 614 in. high, inches in height, and havinga smooth, flat sealing surface.7.1.
19、2 Rubber Boot Boot(2), shall cover the anode manipulator assembly to prevent electrical shock.7.1.3 The top of the housing shall be fabricated from an electrical and thermal insulating material, such as Bakelite, and shallsupport the following items:7.1.3.1 Relief Valve Valve(3), to relieve excessiv
20、e pressure during the melting process.7.1.3.2 Inlet Fitting Fitting(4), for argon.7.1.3.3 Outlet Fitting Fitting(5), for connecting to a vacuum pump.7.1.4 Water-Cooled Lower Housing (6), approximately 534-in. inches in diameter and 512 in. high inches in height containingthe copper melting crucible.
21、 Its upper surface shall be fitted with a neoprene O-ring to seal against the upper anode housing.7.1.4.1 The lower housing shall be capable of being inverted for removal of the button after it has cooled.7.1.5 Jack Jack(7), to raise the lower housing against the upper anode housing, compressing the
22、 O-ring and sealing thecrucible chamber.7.2 DC Electric Welder Welder(8), to provide an arc current of 400 A to 600800 A.7.3 Pressure Regulator Regulator(9), two-stage, for argon gas.7.4 Vacuum Pump Pump(10), having an initial pumping rate of 50 L/min.L/min or more.7.5 Wire Brushes, to clean the cru
23、cible.7.6 Tamping Rod, suitable for packing the sample into the crucible.7.7 Foot Switch, to provide low and high power settings (optional). If a foot switch is not available, the low to high power andthe high to low power transition can be performed with the rheostat designed for adjusting the curr
24、ent.7.8 Control Panel (11), containing the master power switch and rheostat for adjusting the current.Legend:(1) Anode Housing (7) Jack(2) Rubber Boot (8) DC Electrical Welder(3) Relief Valve (9) Pressure Regulator(4) Inlet Fittings for Argon (10) Vacuum Pump(5) Outlet Fitting for Vacuum (11) Contro
25、l Panel(6) Crucible Housing (12) Power CableFIG. 1 Schematic of Electric Arc Remelt FurnaceE1306 1728. Reagents and Materials8.1 Argon, Argon Gas, 99.99 %, supplied from a gas or liquid.liquid tank.8.2 Anode, graphite, graphite or tungsten, 12-in. inches in diameter and 212 in. long inches in length
26、 with a tapered tip.9. Hazards9.1 Wear safety glasses with side shields, or full face shield.9.2 Wear insulated gloves when changing hot electrodes and handling hot buttons.9.3 An electrical shock hazard exists if the rubber boot is removed from around the anode manipulator assembly at the top ofthe
27、 furnace.9.4 An exhaust vent shall be installed over the furnace to remove any harmful fumes that may be given off during the meltingcycle.If fumes evolved off during melting have been determined to be hazardous then an exhaust vent should be installed over thefurnace.10. Preparation of Apparatus10.
28、1 Initial SetupRefer to Fig. 1.10.1.1 Attach the cooling water to the apparatus and adjust the flow rate toper 34 L/min.manufacturers recommendations.10.1.2 Attach the argon supply and adjust the two-stage regulator output to 6 psi (41 kPa).per manufacturers recommendations.10.1.3 Attach the vacuum
29、pump.10.1.4 Attach the dc electric welder to the apparatus at the control panel.10.1.5 Attach the graphite anode to the manipulator assembly.10.2 Preparation of AnodeThe lifetime of the anode can be extended significantly by dipping it into the molten metal. Whenthis procedure is used, it is imperat
30、ive that there be a separate anode for each type of metal or alloy to prevent cross contaminationof the samples.11. Procedure11.1 Turn on the water valve and the master power switch. Adjust the current at the control box so that the low power settingwill be 400 A and the high power setting will be 8
31、00 A. A fixed power between 400 A and 800 A can also be used.11.2 Clean the melting crucible with a wire brush before each melt.11.3 Charging the Crucible:11.3.1 Weigh sufficient sample to fill the crucible. Material density and the form and size of the chips or turnings will determinethe weight of
32、the sample whichthat can be placed into the crucible. Be certain that Ensure the entire sample is contained withinthe crucible and that none is above the top edge. Carefully pack the sample into the crucible with the tamping rod. Powdered metalsmay need to be compacted before melting. Use special ca
33、re when compacting powdered metals.NOTE 1It will take approximately 40 g of zirconium and zirconium alloy materials to fill the crucible.NOTE 2It shall be determined experimentally the exact quantity of material to charge the crucible and the correct current and time to produce asample. The maximum
34、melt time should also be determined to avoid damaging furnace components.11.3.1.1 It should be determined experimentally the exact quantity of material to charge the crucible, the correct current and thecorrect time required to produce a sample. The maximum melt time should also be determined to avo
35、id damaging furnacecomponents.11.3.2 Rotate the lower body into position. Raise the crucible with the jack until the O-ring is firmly seated against the upperbody to close the furnace.11.4 Flushing the Crucible:11.4.1 Turn the vacuum pump on and open the vacuum valve. Evacuate the chamber until the
36、anode manipulator assembly hasbeen pulled down to its lowest position.NOTE 2The pump will become quiet when a partial pressure of approximately 300 millitorr is reached.11.4.2 Close the vacuum valve and open the argon valve until the anode manipulator assembly has returned to its fully extendedposit
37、ion.11.4.3 Repeat the evacuation and argon flushing procedure if desired.11.4.4 Leave the argon valve open after the last flush to maintain a positive pressure during the melting process.11.4.5 Turn off the vacuum pump or close vacuum shut off valve.11.5 Melting the Sample:11.5.1 Place both hands on
38、 the anode manipulator assembly. Depress and hold the foot switch in the low-power position.Energize the welder. Lower the manipulator assembly until the arc is initiated. Continue to lower the manipulator assembly,without touching the sample, until the charge is completely melted.E1306 17311.5.2 Wi
39、thout interrupting the circuit, increase to high power with the foot switch. Hold for After maximum power is attainedhold melt for approximately 30 s. Keep the anode close to the molten pool without touching it. The current can be controlled bymoving the anode closer or further from the molten pool.
40、NOTE 4To coat the anode with metal as suggested in 10.2, with the power still on high, thrust the anode down quickly through the molten pool ofmetal until it just touches the crucible bottom. Then bring it up quickly to clear the metal.11.5.2.1 To coat the anode with metal as suggested in 10.2, with
41、 the power still on high, thrust the anode down quickly throughthe molten pool of metal until it just touches the crucible bottom. Then bring it up quickly to clear the metal.11.5.3 After approximately 30 s minimum at high power, release the foot switch maximum power, de-energize welder and guidethe
42、 manipulator assembly upward to its raised position.11.5.4 To prevent oxidation and maintain a bright shiny surface, allow the button to sufficiently cool for at least 60 s beforeopening the chamber.11.6 Removal of the Sample:11.6.1 Close the argon valve if desired. Open the chamber by releasing the
43、 pressure on the jack.11.6.2 Invert the lower body to remove the button. Allow it to cool to room temperature before handling.11.6.3 Examine the sample to assureensure that all material has been melted and the sample is homogeneous. fully melted. Ifnot, invert the sample and remelt.11.7 Preparation
44、of the Sample for Analysis:11.7.1 Machine the surface of the button flat and smooth, suitable for analysis.11.7.2 The button may also be chipped to provide specimens for test methods requiring solutions or chips.12. Keywords12.1 arc melting; button melting; melting; remelting; sample preparationASTM
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