Minor elements occurring in high speed steels do not exceed a total of two percent Such steels of our Works manufacture designated as T.H.S. a are of the conventional type 18-4-1. The time-scale method of plate calibration due to Smith
has been adopted and applied to the ferrous analysis of the above samples; the spectra evaluated and compared with the usual method of log ratio of galvanometer deflections against composition. The elements receiving attention were manganese, silicon and vanadium. Conventional spark technique for exciting spectra was used. The standard deviations of results which have been computed, do not exceed 2 to 3 per cent of contents

Bhaduri, B N

English

IACS Institutional Repository

EVALUATION O F, SPECTROGRAMS OF HIGH SPEED STEELS FOR MINOR ELEMENTS. PLATE CALIBRATION METHODBy  B. N. BHADURI{Received for pubilcalion, June i6, 1949)ABSTRACT. Miuor element''. ()ccurring iu high specil steels do not exceed a total of two per cent. Such .steel.s of onr Works manufacture designated as T.H.S.a are of the conventional type 18-4-1. The tiinc-scalc method of plate calibration due to Smith has been adopted and applied to the ferrous analysis of the above samples; the spectra evaluated and compared with the usual method of log ratio of galvanometer deflections against composition. The elemenl.s receiving attention were manganese, silicon and vanadium. Conventional spark technique for exciting spectra was used. The standard deviations of results which have been computed, do not exceed 2 to per cent of content,s.I N T R O D U C T I O NThe method of plate Calibration for the evaluation of spectrograms can best be carried out in case of alloying elements occurring in small percentages. A method given by Smith (1945) of the British non-ferrous metals Research Association has been used iu the analyses of non-ferrous alloys. The method is being adopted and applied to the analysis of ferrous samples such as high speed steels. The eleu ents considered are manganese, silicon and vanadium, the total contents of which do not exceed two per cent in the given alloys.The basis of method of plate calibration arises out of known relative intensities of manganese triplets 2949.2, 2939.3 and 2933.1. These values were derived from a consideration of ”  statistical weights ” and given by n, M. Smith as 7 : 5 : 3 .  The ratios are independent of the source of excitation.As applited to ferrous analysis, it was, however, not possible to include Mn ,2949.2 owing to its own interference with an iron line having the same length (Fe II 2949.205). In what follows, therefore, two lines, Mn 2939.3 and Mn 2933.1 formed the calibration pair.P R O C E vS STechnique : The ai^paralus used in exciting the .spectra and in the photometric work and the processing of plates is described underneath 'Volts —  230 A . C.Condenser    —  0.005/iF- -■ "■  15,000 V spark■ ' 22,000 V wave peak.3—I7I2P—S38348 B. 2V. BhedwiTransformer 1/4 KVA tapping from 15,000 VAdded inductance NilSpark gap 2 mm.Electrodes Samples, chill-cast, flat surface.Counter electrode H. S. brand carbon also flat surface,Pre-sparking 3 mins.Spectrograph E 478 LittrowSp. phic slit 7 divs (=0.0175 mm)Photometer slit 8 divs (=0.016 mm)The apparatus are all of Hilger’s specification and of Hilger manufacture. Photographic plates ~  Ilford Process Developer — ID 13 No. i and 2 in equal proportions.Development — 4 mins.Flat surface technique of spark excitation with a condensed spark of roljtine type was used.Reproducibility: In order to test the reproducibility of spectralintensities a continuous spark of 25 secs, duration on a chosen sample against carbon was given with spectra distributed throughout the plate. The data are given in Table I.Table Ia 9S'!i ffiCiD-Av(!)fO.OOA 0 N 3 aIDQQD-Avid)1 67 0,80 “ 0.01 120 0.54 0.002 69-5 0.78 “ 0.03 127-5 0.52 “ 0.023 66 o.k) -O .O J I2X 0-54 0,00'1 65-5 0.81 0.00.01t)0120 0.54 0.005 70 0.78 —0.03 126 0.52 “ 0.02 5d*=:.(X)47fitd.6 6q 0.78 —0.03 Std. 125-.S 0.5? “ 0,0266 O.81)deviation deviation7 “ 0.01 120 ‘ 0.54 n.oo' I W '63 0.828 n.trr 117-.S 0-.S5 O.OI ffs; \ ---\ n9 63 0.82 0.01 =o.oj,3 117 0.55 o.oi «o,oi6 ' 'If) 66.5 0.80 “ 0.01 in% 127 0.52 “ 0.02 in %u 65 0.81 0.00 2.S% 119.5 0.55 0.01 3%s8-562.50,860.830.050.02 117-50-570.550.03 'O.OI62.5 0.83 « 0.02 116,5 0.56 0.0262 0.83 0.02 JI7 0-55 O.OI16 5S 0,86 0.03 113.5 0-57 0.03T7 62 0.83 0.02 h6.5 0.56 0,0218 63 0.82.AM CtO.OI 122 0*54 0.00Clear plate Av. 420 nun,I h e  deft^tioQs ate the tnean of two readings obtained by measuring the line each way as the plate is moved from one side to the other. The standard deviations of densities as obtained was 2.8% for Mn 2939.1 and 3% for Mn 2933-1*BXPKRIMENa'A.r,A  series of three plates A , B and C was used for making tire blackening curves. As the distribution of spectra over the plate was of some consequence in sampling, spectra were distributed evenly and were noted. The sequence is shown in Table II'1'am,k IfDistribution of spectraUualuation of SpeclrogrAms of High Speed Steels, etc. 349Plate Alloy used Kxposurc Time of exposureA. (13^B&C. (13)D.E.1-3 /1.6 7"013-151*49-12J3-3617*2021-2425*281-1020-29jr-1314*3617-19I, 2,X2,33,23,24 3,4,14,13,25,26 5,6,j6,IT,27,28 7,388.199.20 10,21I I , 22Sec, 10,, 1520M„ 45,, 60„ 901015202530456025,,10203<»10203^1251-433-1625-285,226/337,248,179,iS30.1911.2032.212510203025‘ 'T h e  table shows the distribution for all the plates nsed in the experiment, ^he spectra are numbered serially from top to bottom.350 n. N. BhadutiSpectra with exposure time of lo/ 15 etc. to 60 secs, were photographed. The spark used w as coutinuous with pre-sparking as described. The number, of spectra of each duration in case of a plate is given in Table II. A ll such results are included in the table. , •B I< A C K  E N 1 N O  C U R V E S  , ,Blackening curves were drawn from data given in Table III, where mean values of densities and deflections for manganese lines from the three plates A , B and C are given, the density (Sug. Def. Glas., 1946) being defined asI>=log doldwhere do is the deflection obtained from clear plate, i.e., base plus unesjposed processed emulsion and d, deflection due to the line. Such blackening curves are shown plotted in Fig. i .  The plot is of densities against log time ofLog-lime'of exposure’F i g . 1Blackening curvesexposure. The separation of curves along axes parallel to abscissa are measured giving Ae (log exfiosure time ratio) for different values of densi­ties.. This is shown in Table IIJ. The mean of log exposure time ratio (Ae) thus measured gives, attributing a valite 100 to the photographic intensity of Mn 2939. a value equal to 60,3 for Mn '2933 ; Baly's value on a consideration of statistical" weights b e in g '6o7i .  No correction,for hack* ground was made but the agreement afforded wa.s excellent*  ^ . > i ,T xbuh IIIEvaluation of Spectrograms of High Speed Steels, etc. 351Time ni exposure1 lOU(Mn 3939)Defleetion Deiisitv(Mn 2933)Deflection DensityA 153 0..44 3^8 0.23 0.6 ’ 2 .4‘> 1 2.30 2.20B I.S2-5 0.44 .^37 0.25 1 1H)'* C X44.4 0.44 322 U.26 0.7 I2.23 ! 2,40 3.25Mean 150 0.44 332-3 0.25 10.8 12.20 1 2.35 2,20hogjt 3.0U 2.78 I1 !--- . - 0.9 12.10 j  2.35 2.20A 8910.6s 1 ^59 0.4,0 I.o i 2.10 1 2.30 2.20B 79-5 0.63 1 ^77 ‘■ *•37 iC 90.9 U.64 ^57 0.40 1.1 2.15 i 2*13Mean 86.^ 6 0.64 1 164.3 0.39 1.2 2.18 i  —Log Zf 3 -17'i j 2.96 1— — „ - - ^ - - — At U.22 i U.34 0.22A 62.7 U.80 116.2 ' * ‘ 54 Mean A« 0.22B 73.4 0.76 J37 0.48 Antilog 0.7S20'^ C 67.0 « 7 5 122 0.51Mean 67.3 0.77 I2 5-I 0.51 Photographic IntensityLog It 3 -3 0 '' 3.081 Mn 2229 100- - --- - . . ----- — - ...— ._ _ _ —.. Mn 2933 60.3- Data according to BalyB 51,2 0.92 104.2 U.61 Mn 2939 100=5 * , C 44.2 0.95 86 0.65 Mn 2933 60.1Alean 47.7 0.94 94.6 0.63Log It 3*398 3.178A 56 1.04 73 0-74Bas-5 T.07 74.5 0.75,^ 0" C34.I 1.07 ' 66 0.78Mean 35.2 T.06 71.2 0,76Log It 3 *4 7 7 3*257 *-A 19 i.32 39 l.O lB 24 1.25 51 o«9i45'' C 22 i.a6 42.4 0.97Mean 21.7 1.28 4 4 *^ 0.96Logit 3-653 3*433A 12.5 1.50 ?S i*LSB 18.2 1,36 41.2 J.OI60" C 16,0 ^•39 32-5 T.09Mean 15.6 1.43 3.3.9 1.08hog It 3.778 3-558.1‘^ '■5 -  ! 3.35Clear plate Av. 406 mm.m B. ‘Nv BhaduriIn all subsequent experiments a calibration pattern as described above was included in the plate. Blackening curves were drawn in each case. Data for D, K and F plates are given in Table IV -V l.T able IV----------------------------------------- 1Mn 29301Mn 2Q33Time of Density Plate DcatposnreDeflection Density Deflection Densityto" 128 U.43 193 0.24 0-5 2.20124 0.44 192 0 .2 5T14 0.47 186.5 0.26 0.6 , iJ-45Mean 123 0.44 igo-5 0.25 0.7 \ a.70no" 53 0 54 98.5 0.54-----------53 C)-53 99.5 0.53 Mean \2 '4 5‘ 54 0.52 . I02 0.52 'p.2 4 SAntilog 0-7 5 5Mean 5 3-3 ‘^ '53 100 0-53Photographic In-30" 32 1.03 64-5 0 72 tensity36 0.97 72 0.6734-5 a.99 70 0.68 Mn 2939 lOOM n8933 56-9Mean 34-3 1.00 68.8 Q.69 111Clear plate Av. 338 nimT aBI.15 VTime otMn 2939 Mu 2933Density Plate Kexposure ...... 1Deflection Dciisiby Deflection ! Densityto"" 177*5 0.35, - -  -  - j251“ ' ' 0.20 0.4 3,55183.0 ‘■ >'34 261.5 . 0.190.37 2 5 r -5 0.20 0.5 2.32Mean 177.3 ^^-35 2 5 5 -0 il'20 0.6 a. 1520" 117-5 ‘■>‘53 190 0.32 0.7 2.2091.5 0.64 159-7 O.40 Mean ' 2.28Mean8i .2 0.69 149 0 -43 Ae ^ 0.22896.7 0 62 166.2 0.38 A nil log 0.77257.7 o.«4 1 110.2 0.5^ ^ Photographic lii-5 9 *^^ ‘>'83 !! 113.7 ‘->'55 tensity5 « * 5 0.88 103.2 t>-59Mn 2 9 3 9  Mn 2933Mean S^>-4 0.85 108.7 0.571 too S9 -*Clear plate Av. ^oo mm.Evaluation oj Spectrograms of. High Speed Steels, etc. S53T a»i.b VI1Mn 293Q Mn 3939Time of 1Exposure ’©eflecHon Density Deflection Density Density Plate F.(IVfeau) (Mean)10^' 1i 172.8 0.36 258.7 0.44 0.4 2.4020^ Si.7 0.69 152-7 0.42 '•^'5 2.1330"' 1 4« 0.92 100,2 0.60 0.6 2.001 1 n.7 2,00!0.8 ^^03Mean 2.110.211Antilog 0.789Photographic In­tensityMn 2939 ion1 1Mil 2Q33 61.5Clear plate Av. 400 mm.Giving the photographic intensity a value 100 for Mn 2939, the values were 56.9, 59.2 and 61.5 respectively for Mn 2933 for plates D, E andHaving constructed the blackening curves for plates A, B and C (Fig. i) and obtained the mean a second plot was made with log It as one axis and deflection the other. This shows little scatter. The data are taken out of Table III. The calibration curve so obtained is shown in Fig. 2*Log //F ig . 2Calibration carveS54 B. N, BhiidttriWe now come to a stage of drawing intensity-calibration curves. As in all cases of high speed steel analysis exposures having been standardised at a fixed value of 25 secs., a parameter log las derived from log Jt-log 25 was used instead of log It in plotting intensity-calibration curves. Such a curve is shown plotted in Fig. 3, for plate D. The data are from Table VJf. .F ig. 3Intensity calibration curve Table VIITime of exposurePlate n . 10^ ' 20"30"Mn 2939 Mu 2933Deflections^2353-334.2Log 7jt (log /f-log 25) Deflections. . . . .  11190.5 1 1 100 68.8I'Og J25 (log HAog 25)1.602.1.9032.0791-.3571.6581.S34Clear plaie Av. 338 mm.H a te F . lo" 177-311.6021 ■'! 255 J -37470" Q6.7 1.903 166.a 1.675j 1 2.079 i ,108.7 1.851♦  Cleat plate Av. 400 mtn.Plate F . 10" 172.8 1.602 »s8-7 i^3 9 i20" 81,7 ^•903 152-7 1.6923C*' 48.0 3.079 100.2 1.868Clear plate Av. 400 mm*Evaluation of Spectrograms of High Speed Steels, etc, 355 Verificaiion of results.—Suggestion arising out of Smith’s paper for verifica t^ion of variation AVith time of the intensity of emission was tried. No systematic variation was evident and no generalisation was possible as with Smiths. The result for plate D is tabulated in Table VIII.T abi,h VIII Plate DK x p .  No,M n 2930 Mn 2933Exp. No.Mn 2939 Mn 29331l o g  2^r. ^25 I'-'g % hh l o g  2^5 ^35 I'^g hiI 1 9 3 85.1 1.68 47 -9 30 2.00 100,0 1 .7 3 S3-7a 1,9ft 70.4 1.63 42.7 31 1.98 9 .S-5 1.72 5 --53 i.Q? 83.2 1.66 45.7 22 1.99 97-7 J .72 5 '2-51.9 9 97-7 1.73 5:2.5 ^3 T.98 95  5 1.72 52-53 j 91.3 1.71 51-3 24 2,02 1 0 4 .7 1.74 5 5 'C^6 2.01 102.3 1-75 56.3 1.98 95-5 1.70 50.11 .Q9 1 0 7 *7 1 .7 J 1 51.3 36 1-93 fi.s 1 1.6^ 44-7S 1,99 97  7 1.71 : ,51.3 27 1-93 8 S-J 1,63 42.79 r.g6 1 91.2 I . y n 50.1 28 1.94 87.* t .66 45-7If} ' T .98 95.5 1.71 51.311.93 8 5 .1 T.64 43-7Av. on ioo% basis, mo :53.6In a followini^ table is shown the results of chemical analysis and the uses to which the alloys are put Useful line pairs (Harrison, 1939) for purposes of calibration and for analysis and internal standards are shown in Tables IX  and X .T abim IXChemical analysisS a m p le  K o . U seiM n S i V Cr w( 3 ) .1S ta n d a r d 0.22 0.17 1*17 4.27 18.64(4 t S ta n d a r d  ... — 0.20 0.22 t.22 '1 4.42 18.84(6 ) T e s t  a llo y  . . ! 0 .2 J 0.16 J .2 .'? : 4^35 19.05(7) S ta n d a rd 1 0.20 O.T4 1.26 ! 4*40 19.83(13I C a lib ra tio n  ,., 0,24 0.20 1.44 ' ' 4-701 30.79(3o) S ta n d a rd 0.30, 0.16 1-33 1 4-37 17,^ 8(4 ?) , S ta n d a r d 0-25 0.23 1,40 I 3 -6o, 39-394—1 7 1 3 P — {356 8. N. BkaduriTabu X  Line pairsC a lib ra tio nA n a ly s isI n te r n a l S ta n d a rdM n 2939.30Mn v^33*o6 Si I 2881 s8 V i r  3062.70F e  T 2936.90 F e  II  2885.93 F e  IT 3062.23M n  2933.06Calibration curves.—  ^Two series of plates K and F ar  ^ taken to include calibration patterns distributed evenly over the plate as also exposures from standards. Plaie E includes exposures from a test alloy. Results from plates E and F are shpwn in Tables X I and X II. The results include the usual log R, ratio. \Mu ChartT abi.k XI Plate ESampleN o .Mn 2933 defec. tionFe 2937 Denec’ tion F elo g  K 'Mnlo g  ratio • ofInts. (+)(3) ” 5 7 39  5 2.Q2 0,465 1.81 2.15 1 0.34j(4) 115.0 3 5^.0 3.19 0.504 1 82 2.18 1(7) 115.0 35 5 3.^ 4 0.5H 1.82 2.18 1(30) 80.0 3 7-t' 2.16 <’ •435 i.g6  ^ 17 0.21{42^ 83.0 3 7 7 1 2.20 0.342 J-95 2.16 0.21V ChartS a m p leN oV3063 D eflec- 1 tio n1F e  3062 D e fle c- 1 tion1 'B e’lo g  R lo g  r y T o g / p ^  :i1lo g  ra t io  o fIn ts, (+)(3) 66.7 35-5 j 88 0 27 2 03 2.18 ; i.S(4) 4 9 -« 29.7’ 1.66 0.22 2.1] 2.21 i O.IO(7) 42.7 *7-7 I 54 0 t8 2.14 i2.22 1 0.08(30) 48.7 28 2 1.73 0.24 2.11j2,31 j o .ro(4 *) 4 3 -s «9 1.46 o.r6 2.X412.31  1 0.07Taulk Xl ( c o n t d . )Evaluation of Spectrograms of hiigh Speed !§ieet$, etc. 35fSi ChartSampleNo.<S)(4)(7)<301(4a)187 is8-5 16?.,2 142.7 131 5Vc 2886 Deflec­tion150«3 5 -S132.53^^ -5M3-71.25I.IQ1.22 1,04 0.9Slog K log /„j log/p^t).t)Q7 1.56 1.68u,C75 J.6S 1.74U .0 8 6 i .^ >4 1750.017 1.71O . o l A-7S J.74log ratio ofinlensities (+)tM2n.oQO . I l0.02- 0.01Mn ChartT abi,k XII Plate FSampleNo.Mn 2933 Deflec- lionFe 2937Deflec­tion]log K ;1' mh lOK F^elog ratio ofintensitit.s (+)(3) J09.2 42.5 2-57 0.41 1.82 3 TI 0.29(4) 112.5 36.75 3.07 0.49 1,80 2.14 0.34(7) 1 2 3 -^ 41 5 2 97 0.47 ^ •77 3 11 (>■ 34(30) 857 46 2 I 85 0 27 1.91 2 OQ 0 18(4a) 79-2 42-5 1.86 0.27 1 1.94 2,10 0 16V ChartSampleNoV 3063 Deflec­tionFe 3062 Deflec­tionJ ? =  VFe logK  ^V!111>og/p^1log ratio ofintensities (-f)3^ ) 62 34'2 1 Si 0.2b!'"1 J.Ml1 2.150.1450.3 3 * .5 1 -.S95 0.20 2.0S 2.17 0.097^) 5 .v2 35  7 J-55 0 . J9 2.05 i1 2.14 0,09(30^ 49 -2 34 0 1.45 0,16 2 .oS a-15 0^07(42) 3 7 -5 26.7 3.405 0.15 2.13 2.20 o»o7S5 BSi ChartB . N, BhaduriTabi.e X II (contd,)deflection due to analysis line to that due to internal standard and Id^  /a;, values and their differences derived from appropriate calibration curv *^s E, and F'(not shown) for elements manganese, silicon and vanadium. Calibra­tion curves were plotted with log R and log ratio of intensities against compo­sition. Such curves for elements manganese, silicon and vanadium are shown plotted in Fig. 4. Discussion of results follows. Plate F includes a test alloy. From the appropriate intensity calibration curve (F), compositions of Mu, Si, and V were derived- Values arc tabulated in Tables X III, X IV  and XV)cr d 0>.5 <N|0ft;cuo-STJda01tf)oN.J4(h)o .tid -d CO dsNotePlate K • logjR -X log ratio of iiitensit}’Plate F O log I<-(). log ratio of intensity(c)P ig . 4i 59It« i 'IIb>oi"OIIWi 60 iS. N. Bhadiiri>RSsH3BVOCOCOb£•iSi N MEvaluation of Spectrograms of High Speed Steels, etc.>Xn■ SJia5S >tH00.a•ocd(UP<M361fiuo <a XI O iia■ S COSJSbti'trc ®PO"eO *Snoaw aM Q3 £ £S'8-1c-«>■ so i?qTj*HqThHo 8 MqKi8 ?■<rMq cTj-MQ tl«Ofd d161d drd d d1d d1dIo*S TTW ?n o’ClcM ?n c£N sN S § oCltooClM M -H H H MMM 8 M Hoh% HM O oH* H Hd o d d 6 d d d d 0 d dIs.q ooH 00H Xs.M <rr VOM O'H 1 . Nl M H Mf'f rl r>r (M n '‘i ri ci Cf'8' qI'sq q ‘o S’ 00q ? \oq 8 COqr! ri ci '■'i N ci ClT-lM rsN sw 8~MOMN 8N txCf 8.M 100c^N s;ClM H H H M M M , w M MOC' 00 >-< Cf 00 ■It CO 8 rO O'd cr W w H Cl w MO d C d d 6 d c d C d dlO lOo 0rv ■M s^• \Tj MITJ Mt% R Ov»o a vOvnM M M‘O liTj »/./o 'C 0 CTv 6 T}“ c< I’S d 'ti­ VC‘O n r'i f'l '*r> er, tocn iTj UOLTjrv. GlOl-s, i ' i NiTi Cl 00VO O'VOH ’<r T^JH 1/) '8 rs.wIMf? M5 M« §362 B. N. BhaduriThe standard deviations of la  results are1.5 for Mn <  1.0 for Si1.5 for V.The accuracy obtained is comparable to usual log’ R method.D I S C U S S I O N  OF R B S U L T S .In the calibration curves given by the two methods (Fig. 4) accuracy obtained was nearly constant. Calibration did not usually produce a single curve applicable to the two plates. This is the more remarkable in the case of manganese. For silicon, however, a single curve suffices. For vanadium two curves are given form sets of closely lying parallel curves.On the application of background correction it can be said that no standard critique of spectral background evaluation ex ists; the emphasis is laid on having a clean plate with little background. Background calcula­tion adds materially to time, a fact which militates against ordinary routine business. No attempt was thus made to calculate this factor. These facts point to a conclusion that plate calibration does not usually compensate for responses of plates. Nonetheless, the method described is simple and can be of general use. Further work might also give better corroborative results.A C K N O W U E D O M R N T.0The author gratefully acknowledges to the authorities of the Tata Iron Steel Co, Ltd. for permission to publish the paper.R  & C L aboraiokius,TIRCO. jAMSHRUPORrR E F E R E N C E ! ?Harrison. G. R., M.I.T., Wavelength Tables.Smith, T>. M., 1945, Collected papers, H.N.F.M.R..'\.Sp. phic Discussion Group, 1946, Sugge.«ted Definitions, Glass; ow.

Evaluation of Spectrograms of High Speed Steels for Minor Elements Plate Calibration Method

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Evaluation of Spectrograms of High Speed Steels for Minor Elements Plate Calibration Method

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