ASTM_C_1444_-_00.pdf

Designation:C 1444 00Standard Test Method forMeasuring the Angle of Repose of Free-Flowing MoldPowders1This standard is issued under the fixed designation C 1444;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 Particle size,shape,and bulk density will affect theflowability of powder material.This test method is used for thedetermination of the angle of repose of free-flowing moldpowders.At angles greater than this value this material willflow.1.2 The values stated in inch-pound units and degrees are tobe regarded as standard.The values stated in parentheses arefor information only.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2E 1169 Guide for Conducting Ruggedness Tests23.Significance and Use3.1 This test method indicates the ability of a mold powderto flow freely.3.2 The property of powder flow is an important propertyfor the correct functioning of a mold powder.Good powderflow properties help to ensure complete coverage of the moltensteel in the mold by the mold powder providing,in addition toother benefits,insulation of the molten steel.4.Apparatus4.1 Funnel,with a discharge spout opening between 0.25 in.(0.64 cm)and 0.38 in.(0.97 cm)with a capacity to holdapproximately 0.25 lb(113.5 g)to 0.50 lb(227.2 g)of moldpowder.4.2 Ring Stand,with one ring,sized to hold the funnel.4.3 Stopper,sized to fit the funnel discharge spout opening.4.4 Base Plate,flat,rigid,wooden or metal,at least 12 in.(30.5 cm)by 12 in.(30.5 cm).4.5 Glazed Paper,4.6 Calculator,with trigonometric functions.4.7 Calipers,with measuring range up to 12 in.(30.5 cm)to60.01 in.(0.025 cm).4.8 Block,with height of 1.5 in.(3.81 cm).5.Procedure5.1 Obtain approximately a 1-lb(454 g)sample of the moldpowder.The sample should be homogeneous and representa-tive of the bulk material.Place in a jar container 30 to 50%larger than the sample to allow for remixing.5.2 Measure the internal diameter of the funnel dischargespout in inches to the nearest 0.01 in.(0.025 cm).5.3 Place the ring stand with funnel on a sheet of glazedpaper on the base plate.Level the base plate along twoperpendicular horizontal axes.5.4 Place the height block in position under the funnel,adjust the funnel until the nozzle contacts the height block,lock the funnel in position,and remove the height block.5.5 Insert the stopper into the funnel nozzle.5.6 Feed the mold powder into the funnel until nearly full.5.7 Remove the stopper from the funnel and continueadding the mold powder into the funnel at a rate similar to itsdischarge rate.When the tip of the mold powder cone formingon the base plate enters the funnel nozzle,stop feeding themold powder into the funnel.5.8 Using the calipers,measure the diameter of the cone infour places to the nearest 0.05 in.(0.13 cm).Average these fourtest observations and record this test determination to thenearest 0.05 in.(0.13 cm).5.9 Return the tested specimen to the jar container andremix to homogenize.Repeat 5.2-5.8 two more times andrecord the three test determinations as D1,D2,and D3.6.Calculation6.1 Calculate the test result as follows:Angle of repose 5 tan212H/DA2d!#(1)where:1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.03 on PhysicalProperties.Current edition approved Oct.10,2000.Published December 2000.Originallypublished as C 1444 99.Last previous edition C 1444 99.2Annual Book of ASTM Standards,Vol 14.02.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.H=height of the cone 1.5 in.(3.81 cm),DA=average,to the nearest 0.10 in.(0.254 cm)of thethree test determinations,D1,D2,and D3from 5.9,andd=internal diameter of the funnel nozzle,in.7.Report7.1 Report the following information:7.1.1 Designation of the mold powder,source,and date.7.1.2 Angle of repose to the nearest 0.1.7.1.3 Date of the test and name of the operator.8.Precision and Bias8.1 Ruggedness DataRuggedness tests were conducted in1997,following the procedures outlined in Guide E 1169,onan angle of repose procedure in which the funnel height abovea fixed diameter circular disk was continuously increased untilthe maximum mold powder cone height was reached.Rugged-ness variables studied included the height of the bottom of thefunnel above the disk,the funnel discharge spout diameter,thefunnel composition,the disk diamete