1、Designation: E 2014 99 (Reapproved 2005)Standard Guide onMetallographic Laboratory Safety1This standard is issued under the fixed designation E 2014; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the outline of the basic safety guide-lines to be used in a metallographic laboratory. Safe workinghabits are discussed
3、for various tasks performed in a metallo-graphic laboratory.1.2 The sections appear in the following order:SectionScope 1Referenced Documents 2Terminology 3Significance and Use 4Heat Treating 5Specimen Preparation/Sectioning 6Specimen Mounting 7Mechanical Grinding/Polishing 8Chemical Safety 9Electro
4、lytic Polishing/Etching 10Sulfur Printing 11Laboratory Ventilation/Fume Hoods 12Chemical Spills 13Photography 14X ray/Electron Microscopy 15Keywords 161.3 This guide does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this st
5、andard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E3 Practice for Preparation of Metallographic SpecimensE7 Terminology Relating to MetallographyE 340 Test Method for Macroetchin
6、g Metals and AlloysE 407 Practice for Microetching Metals and AlloysE 883 Guide for Reflected-Light PhotomicrographyE 1180 Practice for Preparing Sulfur Prints for Macrostruc-tural ExaminationE 1558 Guide to Electrolytic Polishing of MetallographicSpecimens3. Terminology3.1 DefinitionsAll terms used
7、 in this guide are eitherdefined in Terminology E7or are discussed in 3.2.3.2 Definitions of Terms Specific to This Standard:3.2.1 agreement statea government body that has beengranted regulatory authority over by-product materials andradiation-producing devices by the United States NuclearRegulator
8、y Commission (USNRC).4. Significance and Use4.1 This guide is intended as a summary of safety practicesin the metallography laboratory. It can be used as a trainingmanual for those new to the field of metallography and as arefresher to those who are experienced.4.2 This guide is not intended to be i
9、nclusive of all safetyconcerns encountered in a metallographic laboratory. Severalbooks that provide safety information are available (1-16).34.3 Before operating any equipment, it is advisable to readand understand the accompanying manuals and to follow anyspecified safety guidelines.4.4 Material s
10、afety data sheets (MSDS) for chemicals beingused in a laboratory should be on file and readily accessible.When working with any chemicals, especially for the first time,one should review the MSDS supplied by the manufacturer andfollow any safety guidelines suggested. The most current andapplicable M
11、SDS should be on file for a given product orchemical.5. Heat Treating5.1 Personal Protective Equipment, should be utilized. Theminimum protection should include safety shoes, safetyglasses, and heat resistant gloves. When utilizing furnaces athigh temperatures (1900C), a heat resistant suit and face
12、shield should be used in addition to gloves and glasses.5.2 Furnace Load WeightsThe weight limit that can besafely loaded and unloaded manually into a furnace at tem-perature should be established by the laboratory manager. The1This guide is under the jurisdiction ofASTM Committee E04 on Metallograp
13、hyand is the direct responsibility of Subcommittee E04.17 on Criteria for Metallo-graphic Laboratory Evaluation and Safety.Current edition approved Nov. 1, 2005. Published November 2005. Originallyapproved in 1999. Last previous edition approved in 1999 as E 2014 99.2For referenced ASTM standards, v
14、isit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The boldface numbers in parentheses refer to the list of references at the end ofthis standar
15、d.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.weight limit for manual loading should be determined forspecific procedures. This may be increased or decreaseddepending on availability of equipment to aid in loading orunloading mat
16、erial; configuration of samples, which couldmake loading and unloading more or less dangerous; or theability to utilize more than one heat treating technician inloading and unloading, or combination thereof.5.3 Furnace Loading and UnloadingWhen working witha furnace that requires a removal of a ther
17、mocouple prior toloading, care should be taken to handle the thermocouple withheat resistant gloves or tongs.5.3.1 Material should be loaded into the furnace with tongs.The tongs used should have the proper configuration for thespecimen to be loaded. Tongs should be properly maintained.5.3.2 When se
18、veral small or oddly shaped specimens are tobe heat treated, a tray or wire basket may facilitate loading andunloading.5.3.3 The surface of an oil quench bath can ignite duringquenching. Caution should be taken to avoid being burnt. Donot lean over the oil quench tank when pieces are beingquenched,
19、and cover the tank as quickly as possible toextinguish the flames.5.4 Salt bath furnaces should be set up in accordance withthe manufacturers instructions, along with state and localenvironmental regulations. Exhaust systems are required forgases generated. Some states may regulate exhaust systemspe
20、cifications.5.4.1 Personal protective equipment should include a heatresistant apron, sleeve protection, safety glasses, safety shoes,and face shield.5.4.2 The start up of a salt bath should be performed by aproperly trained technician.5.4.3 When long cycles with little attention are performed,the t
21、emperature control devices should have alarms with limitsand shutdown capability.5.4.4 Keep all water or moisture away from and out of thesalt bath. Clean the pieces to remove cutting fluids or any otherresiduals. After cleaning, dry all the pieces thoroughly.5.4.5 Clean and dry baskets before each
22、use. Moisture maybuild up on the salt dried on the basket.5.4.6 To avoid shock, do not place metal, baskets, orsludging tools between electrodes while power is on.5.4.7 Wear a face mask when filling furnace with dry salts.5.4.8 Keep work area clean. Do not keep boxes, pallets, orother highly flammab
23、le items in work area. Keep floors cleanto avoid slips, trips, or falls.5.4.9 Keep salt containers tightly closed to avoid moistureadsorption in dry salt.5.4.10 Establish periodic checks and safe procedures forelectrodes, sludging, rectifying, and the use of graphite rods.5.5 A standard operating pr
24、ocedure (SOP), including a jobsafety analysis (JSA), should be completed for every heattreating practice performed, listing any potential hazards anddescribing the safe operating practice. A summary of recom-mended safe practices can be found in Table 1.6. Specimen Preparation/Sectioning (17)6.1 Saf
25、ety glasses should always be worn when operatingsectioning equipment. Ties, loose fitting clothing, and jewelrycan become tangled in the moving parts of equipment andshould not be worn.6.2 The cutting blade of a bandsaw is exposed and can bedangerous. A guiding device, such as a block of wood, shoul
26、dbe used to maneuver the specimen, thereby, reducing thepossibility of hand injury.6.3 The major danger from abrasive saw operations is fromflying debris from a broken wheel. This danger is normallyeliminated in modern equipment by shielding the cutting areafrom the operator. A cutoff saw should nev
27、er be operatedwithout a shield in place.6.4 Sectioning often results in the formation of burrs on theedges of the specimen. These burrs can be quite sharp andpotentially dangerous. The burrs should be carefully removedby filing or grinding.6.5 Wet grinding is always preferred over dry grindingbecaus
28、e of the reduced amount of dust and reduced heatdamage to the specimen. The dusts generated from grindingany metal are a health hazard. Those generated by grindingmaterials, such as beryllium, magnesium, lead, manganese, andsilver, are extremely toxic. These materials should be groundwet under a ven
29、tilation hood, and a face mask should be worn.6.6 A SOP, including a JSA, should be completed for eachpiece of equipment being used while sectioning or preparingspecimens, listing any potential hazards and describing the safeoperating procedure. Recommended procedures for the metal-lographic prepara
30、tion of various materials can be found inMethods E3.7. Specimen Mounting7.1 The major safety concern while using either automaticor manual mounting presses involves the potential of burnsfrom contact with hot equipment or specimens. Operatorsshould wear insulated gloves to protect hands.7.2 Prolonge
31、d contact with many mounting materials cancause irritation to the eyes and skin; gloves are recommended.Also prolonged exposure to the vapors and dust generatedduring the mounting procedure is not recommended. Consultthe product label and MSDS of the specific mounting material,and use the protective
32、 equipment recommended.7.3 When using castable resins, work should be completedunder a fume hood. The corrosive, explosive, and carcinogenicproperties vary widely with different castable resin compo-nents, and users should be aware of the most current andTABLE 1 A Summary of Recommended and Discoura
33、gePractices When Heat treatingRecommended Practice Discouraged PracticeDevelop SOPs and JSAs Lift specimens $ 10 kgWearsafety shoes Lean body over bathsafety glasses or face shieldheat resistant gloves Leave tank contents uncoveredUse tongs, tray, or wire basket whenhandling samples Contact electrod
34、es with conductiveKeep specimens and surrounding materialarea free of moisture and debrisE 2014 99 (2005)2applicable MSDS information and occupational health andsafety issues relating to each component separately and mixed.7.4 A SOP, including a JSA, should be completed for eachpiece of equipment us
35、ed for every mounting routine per-formed. The SOPshould list any potential hazards and describethe safe operating practice.8. Mechanical Grinding/Polishing8.1 Injury to operators hands is a very common injuryreceived during grinding or polishing. For manual polishing,small or irregularly-shaped spec
36、imens should be mounted toaccommodate handling. For semi-automatic and automaticprocedures, ensure that all moving parts have come to restbefore mounting or removing specimen holders or beforecleaning the equipment, or both.8.2 When using grinding or polishing equipment, operatorsshould not wear tie
37、s, loose fitting jewelry, or loose fittingclothing, which could become entangled with the equipment.8.3 Some of the lubricating liquids and polishing suspen-sions used during grinding and polishing are flammable andcaution should be taken. The specific manufacturers productlabel and most current and
38、 applicable MSDS should be readbefore it is used.8.4 A SOP, including a JSA, should be completed for allmechanical grinding and polishing equipment, listing anypotential hazards and describing the safe operating practice.9. Chemical Safety9.1 Before using or mixing any chemicals, all product labelsa
39、nd pertinent and most current MSDS should be read andunderstood. The appropriate type of protective clothing willdepend on the task being performed.Again, consult the productlabel and the most current and applicable MSDS for recom-mendations concerning protective clothing.9.2 The safe use, storage,
40、and disposal of chemicals be-comes more complex whenever they are combined or mixed.Experimentation with new combinations of chemical reagentsis not recommended unless conducted by a person knowledge-able in chemistry. Table 2 shows some chemicals oftenencountered in a metallography laboratory known
41、 to be incom-patible with one another.9.3 The hazards involved with handling chemicals arenumerous and often specific to the chemicals being used. Usersshould be aware if there are dangers that are long term,immediate, visible, invisible, and with or without odor.9.4 Only small quantities should be
42、mixed and stored inglass-stoppered bottles filled to capacity. Exceptions includefluorides and strong alkaline solutions, which should be storedto polyethylene or another appropriate container recommendedby the manufacturer for that specific chemical. Any evaporatedsolvents should be replaced to mai
43、ntain a filled capacity.9.5 Chemicals should always be protected from heat andfire.9.6 Spent or exhausted chemicals should be disposed ofpromptly, following all applicable regulations.9.7 Specific Chemical PrecautionsParagraphs 9.7.1-9.7.13 list some specific safety situations that are oftenencounte
44、red in a metallographic laboratory and known to bedangerous.9.7.1 The addition of sulfuric acid to water produces anextremely exothermic reaction. The solution must be cooledduring mixing. While cooling, the acid must be slowly pouredin the water or solvent with constant stirring. Spattering of thes
45、olution must be avoided. Dilute solutions (anything less than100 % concentrated) of sulfuric acid strongly attack the skin,are very hygroscopic, and vigorously attack most plastics.9.7.2 The addition of crystalline chromium trioxide to waterforms chromic acid, a strong oxidizing agent. The reactionl
46、iberates free oxygen, which can be incendiary in the presenceof oxidizable materials.9.7.2.1 Chromic acid cannot be safely mixed with aceticacid or most organic liquids, such as alcohols or glycerol.9.7.2.2 Chromic acid solutions cannot be used in contactwith plastic parts without their eventual des
47、truction.9.7.2.3 Care should be taken to prevent chromic acidcontact with the skin since repeated exposure to even dilutesolutions will cause persistent and painful ulcers that are slowto heal.9.7.2.4 Chromium trioxide is poisonous to humans and acarcinogen.9.7.3 When preparing solutions containing
48、mixed acids,salts in water, or other organic solutions, the acid should beadded slowly to the solvent with constant stirring.9.7.4 Particular care should be taken to avoid skin contactwith acid fluorides since exposure to them, which may passunnoticed at the time, may result in serious burns later.E
49、xtreme caution should be used when handling hydrofluoricacid.9.7.4.1 Hydrofluoric acid will ulcerate the skin if not imme-diately washed off with water. Flushing the area with watermust be followed by the use of a neutralizing cream, such ascalcium glutamate gel, after which a physician should beconsulted as soon as possible. If left untreated, the acid willattack the skin to the bone.9.7.4.2 Hydrofluoric acid, which attacks glass, should beused and stored only in containers made of polyethylene orTFE-fluorocarbon.9.7.5 In those mixtures containing anhydrous aluminumchloride
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