A0-A42 076 EVAUAON AND DE MONSRAONOF THEVIABILT OF SAL /

BATH SOLUTION HEAT U AEROJET ORDNANCE CO JONESBORO

IN HEAVY METALS DlV * F MULLER ET AL. MAR 84

UNCLASSIFIED ARLCD-CR-83048 DAAK10-83-C-OOO5 F/G 13/8 NL

__ 84

11111" L A * 8 .

JJL25i A

MICROCOPY RESOLUTION TEST CHART

NATIONAL BURLAU OF SIANOARDSI I I A

II

Iti

III1WN III1 tll/

cc AD-E401 /

CONTRACTOR REPORT ARLCD-CR-83048

EVALUATION AND DEMONSTRATION OF THE VIABILITY OFSALT BATH SOLUTION HEAT TREATMENT FOR

I DEPLETED URANIUM PEN ETRATORS

J. F. MULLERI R. L. NEAD

AEROJET ORDNANCE COMPANYI P.O. BOX 399JONESBOROUGH, TN 37659

Ii

MARCH 1984

I U.S. ARMY ARMAMENT RESEARCH AND DEVELOPMENT CENTER

" ONTAECOR R EPORTT-CR-83048

APPROVED FOR PUBLIC RELEASE: DISTRIBUTION UNLIMITED

DTIEECTE

IIA I E OJET 12DANE984AN

P.O 8 06 192

FIL MARC 18406 1 0 2 r

HEAVY METALS DIVISION

AEROJET ORDNANCE COMPANYP 0 BOX 399 0 JONESBORO, TENNESSEE 37659 9 615 753 4688

150:84-0606

JFH:dkj

17 May 1984

Department of the Army

U. S. Army Armament Munitionsand Chemical Command (AMCCOM)

Picatinny ArsenalDover, NJ 07801

Attention: DRSMC-LCU-M, Mr. Doug Vanderkooi

Subject: Contract D.AAKIO-83-C-0005, Final Report; Publication of

Reference: (a) Telecon of C. Alesandro/AMCCOM and J. Hughes/Aerojet on 7 May 1984

Gentlemen:

As requested in referenced (a), Aerojet Ordnance Company, HMD, has changedthe quantities from 14,000 and 5,500 to 10,000 and 4,000 M833 and XM829 re-spectively. To verify this change, please review page 26 of the attachedreport.

Distribution of the document is made in accordance with the list shownon pages 30 and 31. The subject contract has been closed out and isconsidered complete with the issuance of this document.

Should additional information be required, please contact me atAerojet Ordnance Company,Jonesborough, TN; telephone (615) 753-4688.

Sincerely,

A( ET ORDNANCE COMPANY

James F. HughesContract Manager

cc: DRSMC-TSS (D) (5 Copies)DRSMC-LCU-M (D)(20 Copies)

Accessions Division (12 Copies)DRXSY-MPDRSMC-CLJ-L (A)DRSMC-CLB-PA (A)DRSMC-BLA-S (A)DRSMC-LCB-TLDRSMC-LEP-L (R)ATAA-SLDRXIB-MT (2 Copies)DRCPM-TMA-TMDSM- 2 o

I

I fADIAD-E401

ICONTRACTOR REPORT ARLCD-CR-83048

IEVALUATION AND DEMONSTRATION OF THE VIABILITY OFSALT BATH SOLUTION HEAT TREATMENT FORIDEPLETED URANIUM PENETRATORS

IJ. F. MULLER

* R. L. NEAD

AEROJET ORDNANCE COMPANYP.O. BOX 399

JONESBOROUGH, TN 37659

MARCH 1984

Li U.S. ARMY ARMAMENT RESEARCH AND DEVELOPMENT CENTER

APPROVED FOR PUBLIC RELEASE: DISTRIBUTION UNLIMITED

The views, opinions, and/or findings contained in this reportare those of the author(s) and should not be construed as anofficial Department of the Army position, policy, or decision,unless so designated by other documentation.

The citation in this report of the names of commercial firmsor commercially available products or services does not con-stitute official endorsement by or approval of the U.S.Government.

Destroy this report when no longer needed. Do not return to

the originator.

Accession For

NTIS GRA&I

DTIC TABUnannouncedJustificatlo

ByDis3tribution/

Availability Codes

Avail andI/orDist Special

la,,

UNC1ASS lFIED

SECURITY CLASSIFICATION OF THIS PAGE (Whmn Date ZntroM

READ INSTRUCTIONSREPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM( 1. REPORT NUMBER 12. GOVT ACCESSION NO. S. RECIPIENT'S CATALOG NUMBER

Contractor Report ARLCD-CR-83048

4. TITLE (and Subtitle) S. TYPE OF REPORT I PERIOD COVEREDFinal Report

EVALUATION AND DEMONSTRATION OF THE VIABILITY OF 2/83 - 1/84SALT BATH SOLUTION HEAT TREATMENT FOR D.U. 6. PERFORMING ORG. REPORT NUMUERPENETRATORS

7. AUTNOR(q) S. CONTRACT OR GRANT NUMBER( )

J. F. MullerR. L. Nead DAAKIO-83-C-0005

S. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASKAerojet Ordnance Company AREA & WORK UNIT NUMBERS

P. 0. Box 399 MMT5824563Jonesborough, TN 37659

Tp OFFICE NAME AND ADDRESS 12. REPORT DATE

. OFCNAEADDRMarch 1984STINFO Div (DRSMC-TSS(D)) 1. NUMBER OF PAGESDover, NJ 07801 30

14. MONITORING AGENCY NAME A ADDRESS(It differant from Controling Office) IS. SECURITY CLASS. (of INS report)

UnclassifiedIsa. DECL ASSI FICATION/DOWNGRADINGSCHEDULE

14. DISTRIBUTION STATEMENT (of thle Report)

Approved for public release; distribution unlimited.

17. DISTRIBUTION STATEMENT (of the obettet ontered In Block 20, I dlfferft from Report)

AI-SUPPLEMENTARY NIOTESis project vas accomplished as part of the U.S. Army's Manufacturing Methods

and Technology Program. The primary objective of this program is to develop,on a timely basis, manufacturing processes, techniques, and equipment for usein production of Army materiel.

IS. K5Y WORDS (Cantlnue ati revero ael If aeceeear? std ldentl7/ Sby bloc~k omber)epleted uranium

alt bath solutionizing1eat treatment-DU process improvement

2 AN A (r-II I'efet'ae am N naaMid7 ldfam fy by Wleek ambee)ACT program to evaluate and demonstrate the viability of a salt bath solu-

ionizing heat treatment for large caliber DU penetrators (0.75% by weightitanium)was conducted. %One hundred M774 core blanks were evaluated to developnd verify the various process stages (e.g., outgassing salt residence times,

(.\ tc) of salt heat treatment. A viable salt bath heat treatment process was

Do , re"I 1473 mTow I oibv 1m is 06oLErr UNCLASSIFIED

seCUITY CL.A*IPrCATqON OP T'HS PA4C(Vm PR AW

SECURITY CLASWICAIION or THIIS PAGE(Whsn Doaet gr

20. ABSTRACT (contd)

developed through this program. A pilot lot of 40 finished machined M4774 pene- I

trators was fabricated under the guidelines of this program and is availablefor ballistic testing. Included in this report is a genera] analysis of facil-ity requirements to implement salt solutionizing heat treatment into theAerojet production stream.

UNCLASSIFIED

4 SECURITY CLASSIFPICATION OF THIS PA~GfKWhen Data thlete.

TABLE OF CONTENTS

PAGE

List of Figures i

List of Tables ii

, Introduction I

Scope I

Material 2

Process Description 2

Resul ts 3

Conclusions and Recommendations 5

Figures 7

Tables 12

Distribution List 30

-4! i

LIST OF FIGURES

Figure 1. Logic diagram of salt solutionizing study process.

Figure 2. Photograph of solutionizing rack and basket fixture.

Figure 3. The equipment used in the salt solutionizing process.

Figure 4. Diagram illustrating thermocoupled core blank.

Figure 5. Heat-up rate of a M774 core blank..

Figure 6. Cooling rate of a core blank when removed from thesalt bath. Thermocouples were located at mid-radiusand near surface of a M774 core blank.

LIST OF TABLES

Table 1 Program Material Selection

Table 2 Salt Solutionizing Study Sample Schedule

Table 3 Program Core Blank - Process Correlation

Table 4 Control Group (Step 1) Results

Table 5 Outgassing Study (Step 2) Results

Table 6 Salt Solutionizing - 1st Iteration (Step 3) Results

Table 7 Salt Solutionizing - 2nd Iteration (Step 4) Results

Table 8 Comparison of TIR Data of Solutionized M774 CoreBlanks - Vacuum Solutionizing vs. Salt Solutionizing.

Table 9 Verification Tests (Step 5) Results

Table 10 Verification Tests (Step 6) Results

Table 11 Pilot Lot Cores

Table 12 Chemical Analysis ot Heat Lots Tested

ii

INTRODUCTION

The objective of the program was to evaluate and demonstratethe viability of salt solutionizing heat treatment as analternative heat treatment process to vacuum solutionizing. Theslow cycle times of the existing process and the high frequencyof maintenance required on the expensive capital equipmentassociated with vacuum solutionizing provided the incentive toAerojet and the U.S. Army to identify an alternate solutionizingprocess. Salt solutionizing was investigated as a method foralleviating these problems. In spite of the fact that a vacuumoutgassing operation must be performed prior to the saltsolutionizing process itself, the quantities of blanks that wouldconceivably be outgassed during any one production-type cycle,greatly exceed those currently vacuum solutionized at one time.This is because the combination outgassing/solutionizing processis limited by the thermal efficiency of the quench operationwhich, in turn, seriously impacts quantities. Therefore, a largenumber of blanks could be outgassed at one time and then sentthrough the salt solutionizing process in smaller solutionizinglots without adversely affecting overall throughput. The smallerlots, in turn, also have the associated benefit of potentiallyproviding a more uniform cooling condition and less distortionthan the combination batch process.

SCOPE

This investigation was conducted in three phases consistingof a total of six development steps at the TNS facility inJonesborough, Tennessee. Each of these steps, excluding thefirst two, used the information obtained in the preceding steps.The program logic diagram is shown in Figure 1.

The first phase, Phase A (Step 1), was the production of acontrol group using current M774 production practices. Thismaterial was used to compare vacuum solutionizing with saltsolutionizing by analyzing the mechanical properties of therespectively heat treated material. The second phase, Phase B,consisting of Steps 2 through 6, developed the most economicaland applicable salt solutionizing heat treatment processconsistent with Aerojet's current mode of large caliber coreproduction. The final phase, Phase C, of the program was theproduction of 40 finish machined and inspected M774 penetratorcores, the blanks of which were salt solutionized using theguidelines determined in Phase B. These cores are available forsubmittal to the Armament Research and Development Center (ARDC)for further evaluation and testing.

-1-

MATERIAL

A total of 141-33mm diameter by 384mm long U-.75 wt. % Ticore blanks were required for this study. The processing stages,reduction of JF4 (green salt) through blanking, used to producethe core blanks for this program were those used in standard M774

operating practices and procedures. The core blanks wereselected from remelt heats with three different titanium levels.Re-melt heat, billet identification, core blanks selected p -billet, and billet titanium content are listed in Table 1. .esethree titanium levels were selected to identify any possilrelationship between titanium level, process variations armechanical properties.

All material was traceable per the applicable sectio.,MIL-C-63308A. Complete traceability was maintained back t(. chegreen salt (UF 4 ) used. The core blanks were identified accordingto titanium level and remelt billet. The blanks from each billetwere consecutively numbered with respect to extrusion order(first material out of extrusion die numbered one and so forth).

PROCESS DESCRIPTION

The government-furnished Sunbeam vacuum solutionizingfurnace was used for the solutionizing of Control Group (Step 1)material. The core blanks for Phases B and C were vacuumoutgassed at Battelle Columbus Laboratories. The Battelle

furnace used was a top loading, 450mm diameter ABAR cold wallfurnace. This piece of equipment was chosen to provideconsistent outgassing conditions. The core blanks were placedhorizontally in the furnace on a sheet of copper, supported by astainless steel stand. At the completion of the outgassingcycle, the blanks were allowed to furnace cool to roomtemperature in an argon atmosphere.

The salt heat treatment was conducted in a NaC1-KCI neutral

salt heated to 850 0 C in the 226 liter steel pot of a gas firedfurnace. The melting point and working range of this salt was665 0 C and 700 0 -890*C, respectively. The blanks were hung incopper-coated, Inconel baskets from a stainless steel rack. Therack had the capability of supporting eight baskets with 160millimeters between core blank centers. The rack and basketfixture is shown in Figure 2. The core blanks were quenched intoa 340 liter, unagitated tank of ambient temperature water. Theimmersion rate was controlled by a mechanically driven verticalshaft. The immersion rate was set at 46 cm/min. for allquenching cycles. The salt solutionizing equipment set-up usedby Aerojet for this program is shown in Figure 3.

All aging was conducted in the Upton lead pot currently used

-2-

in AOC large caliber core production. The aging heat treatment

was performed at 370'C for 6 hours.

RESULTS

The salt solutionizing study sample schedule is shown inTable 2. The core blanks utilized by Aerojet in each step are

listed in Table 3.

The Control Group blanks, Step 1, were solutionized in thegovernment-furnished Sunbeam furnace. The results of hydrogenand mechanical property analyses and tests are listed in Table 4.It was confirmed by this data that the material selected for thisprogram would meet M774 mechanical property specifications whenprocessed according to the applicable production procedures.

The second phase, Phase B, of this program was thedevelopment of a salt solutionizing process. This investigationwas divided into five steps. The first developmental step, Step2, was to deotormino the outgassing characteristics andrequirements of the material selected for this program. Thehydrogen analysis results of this investigation are listed inTable 5. - w determined in Step 2 that outgassing the coreflanks at 850u'" tr two or four hours would result in materialwith acceptable hydrogen levels, (<l.Oppm H 2 ), with the four hour

outgas producing the lowest hydrogen levels. At this stage ofthe program, it was felt that 600 0 C for four hours was a marginaltime-temperaturt outgassing combination (H2 levels near the 1.0ppm limit) and this outgassing condition was eliminated fromfurther consideration.

Utilizing the four hour outgas at 850'C, 36 core blanks wereoutgassed foL Step 3, Salt Solutionizing - ist Iteration. Theoutgassed blanks were heated in the salt, six blanks at a time,for the specified times. The transfer times between removing theblanks from the salt and the initiation of the immersion cyclewere changed from 10 and 20 seconds to 15 and 25 seconds

respectively. The rationale for this change from that originallyproposed was simply the fact that the fastest transfer time whichcould be safely obtained was 15 seconds. An originally intendedincrement of 10 seconds was maintained and the second transfertime was set at 25 seconds.

The results for Step 3 are listed in Table 6. Comparing the

charpy test and microstructure results, it appeared that a saltresidence time of 10 minutes was marginal and that 20 minuteswould be sufficient. To determine the required residence time, acore blank was thermocoupled as shown in Figure 4. Thethermocoupled blank was then lowered into the 850 0 C molten saltbath to determine the material heat-up rate and thus, therequired salt residence time. The signal from the thermocouple

-3-

was recorded on a strip chart and the resulting information isshown in Figure 5. As can be seen, the center of the core blankapproached the bath temperature in five to eight minutes, butseveral additional minutes were required for the salt bathtemperature to recover to the set point. As 10 minute incrementshad been proposed for the program, 20 minutes was chosen as thebest salt residence time. It was determined that by the use of alarger bath or by an increase in the furnace heating capability,a shorter salt residence time could conceivably be used toincrease throughput. The Step 3 data also indicates that thereis no detectable amount of hydrogen pickup by the DU from theexposure to NaCl-KCI salt. This eliminated hydrogen pickup as aconsideration in determining the salt residence time, within therange of time required to uniformly heat core blanks, in thissalt.

In Step 4, the second best outgassing process was combinedwith the two most applicable salt residence-transfer timesolutionizing processes. Table 7 shows the process used and theresulting data. It can be seen from the data that theseprocessing combinations produced material with acceptableproperties. Comparing the results from the two transfer timesused, there appears to be no identifiable effect from theadditional delay. The material cooling rate was analyzed byattaching thermocouples to the surface and sub-surface of a coreblank which was salt solutionized. The results of thisinvestigation are shown in Figure 6. As can be seen, the blanktemperature at the surface does air-cool to below thetransformation temperature of 745*C in approximately 60 seconds.Microstructural examinations did not identify substantial amountsof undesirable microstructure, but it is recommended that a shorttransfer time be used or some type of insulating fixture beemployed to reduce the cooling of the material. Minimizingtransfer time is especially important as the tail ends of theblanks are exposed to the air for a longer period of time thanare the nose areas, prior to immerision into the quench media.

Also investigated under this step of the program was thedistortion of the core blank resulting from the quenching stageof the salt solutionizing heat treatment. Table 8 shows totalindicated runout (TIR) data of Step 4 material. This informationcan be compared to TIR data obtained from M774 blanks processedthrough the Sunbeam vacuum solutionizing furnace, also includedin Table 8. It can be seen from this data that due to theconfiguration of the blanks in the quenching rack, the saltsolutionized blanks were exposed to a more even coolingenvironment, thus resulting in less distortion from thesolutionizing heat treatment.

Steps 5 and 6 were conducted as verification tests on lowand high titanium levels. The resulting data from these testsare shown in Tables 9 and 10. The verification test data, aswell as the control group data, does show that lower Ti contents

-4-

did result in higher slow bend pre-cracked charpy (KQ) andelongation (% E) values. All of the material for this programwas aged for six hours at 3700 C. Tt was not totally unexpectedthat lower Ti content material would exhibit somewhat higherfracture toughness and tensile ductility by virtue of titaniumcontent alone. However, one would have also expected to see acorrespondingly lower hardness associated with these results.This was not found. This correlation, or the lack thereof, hasno specific significance for evaluation of the salt solutionizingprocess.

The final phase of this study was the production of 40finish machined M774 penetrators. From the previous fivedevelopment steps, it was concluded that the optimum process forthis pilot operation was a two hour outgassing cycle at 850 0Ccombined with a 20 minute salt residence time and a 15 secondtransfer delay. Forty three core blanks were selected from thenominal titanium level remelt heat (#3357) and heat treatedaccording to this optimum process. Once solutionized, the coreblanks were all aged together for six hours at 370 0 C. The agedblanks were then O.D. turned and submitted for ultrasonic andO.D. hardness evaluations. Two blanks, NA10 and NAI4, wereselected as representative blanks and submitted for mechanicalproperty evaluations. As shown on the data sheet for thismaterial, Table 11, O.D. hardness testing indicated that 10 ofthe 41 remaining blanks had O.D. hardness values greater than theRc 44 specification limit. The collective hardness range andaverage values for these 10 were Rc 44.2 - 45.8 and Rc 44.7respectively.

In the interests of completing this program, all of the 41remaining pilot lot cores were machined. Of these, 40dimensionally acceptable cores were produced, nine of whichrepresented cores having the out-of-specification O.D. hardness.

CONCLUSIONS AND RECOMMENDATIONS

The salt solutionizing heat treat process established bythis program for M774 core blanks was a two hour outgassing cycleat 850'C combined with a salt residence time of 20 minutes and atransfer delay time of 15 seconds. It should be noted that arecommendation for a 10 minute residence time can be made basedupon a thermocoupled core blank test run. This recommendedresidence time is dependent on utilizing an appropriately sizedsalt bath with better temperature recovery capabilities than thatused for conducting this study.

It was also determined that exposure to the NaCl-KCl neutralsalt used in the solutionizing process did not affect the finalhydrogen level measured in the D.U.-.75 wt. %Ti material. Thisprogram has demonstrated the technical viability of utilizing a

-5-

salt solutionizing heat treatment in conjunction with Aerojetisprocessing of M774 large caliber cores. Some questions do ariseabout the possible utilization of this heat treatment techniquefor other cores (M833, XM829). This is based on the fact thatthese latter cores require higher ductility values than thatspecified for M774 penetrators. The ductility (% E) valuesobtained in this program, in some cases, are lower than the 16%elongation required for both M833 and XM829 cores. In addition,economic, safety and other factors must be fully identified andanalyzed.

-6

iSa It So It ioni z i i .,t W'r.. ,,.rWol Lar(4 Ce i r Ib-r rP. rt w t I r , i :

Phase A Phaso B ;

Step IControl Group - Out-gissinil . i 4 n I ,,*t' . O.. r, t b ltkS

I ' m)fl I z l'V

S.- ic f ini.

V: t Ir t , '

Vr if i, at ion I]'-s

a )-w i I , o]1

4.,r iFr ica7 ion T,.-t

-7-h T f.vo -

I

U

g *U

FIGURE 2: Photograph of solutionizing rack and basket fixture.

* IIIIIIIIII

I ;~'~L

IIIIII1

j ~ TO RECORDER

II .6. COPPER SLEEVE

Figure 4. Diagram illustrating thermocoupled core blank

1 -18 00'

600

-Blank temp.

FA A-Bath temp.200

0 4 6 8 10 12

Figure 5. Heat up rate of an M774 core blank

10

I900S0- Surface

*-Mid-radius

800 ....

I

700

TIME (seconds)

I

I Figure 6. The cooling rate of a core blank when removed from thesalt bath is plotted. Thermocouples were located at

-Imid-radius and near surface of an M774 core blank.II!

I,Table 1. Program material selection

BilletRemelt Billet Number of titaniumheat identification core blanks range

3295 E *14 Low (0.69-0.72% Ti)

I 3357 A,C,D,E,K 113 Nominal (0.73-0.75% Ti)

3303 E *14 High (0.76-0.79% Ti)

I*all blanks from same billet

I

II

I

IIII

II 1

I

L

Table 2. Salt solutionizing study sample schedule

Cores H2Salt Trans- Cores H2 charpy and

Titanium Outgas residence fer Total tested tensilelevel condition time time cores before testedcode code (min.) (sec.) processed age after age

Step 1I LR 6 24

Phase A N R 6 2 4H R 6 2 4

tep 2N 1 6 6N 2 6 6N 3 6 6

Step 3N Xl 10 15 6 2 4N Xl 10 25 6 2 4N Xl 20 15 6 2 4N Xl 20 25 6 2 4

Phase B N Xl 30 15 5 2 4N Xl 30 25 5 2 4

Step 4N X2 S-Q1 6 2 4

N X2 S-Q2 6 2 4

L X-S-Q 8 4 4Step 6

Phase C ilot lot

N *X-S-Q 43 2I Total 141

Codes used:

I Titanium lots (wt. %) Vacuum outqasL = low (0.69-0.72% Ti) R = current solution procedureN = nominal (0.73-0.75% Ti) 1 = 600°C 4 hours

* H - high (0.76-0.79% Ti) 2 = 850 0C 4 hours3 = 850 0C 2 hours

Xl = best outgasOther X2 = second best outgasS-Ql = best residence-transfer combinationS-Q2 = second best residence-transfer combination

X-S-Q = best overall heat treat combination*X-S-Q = best overall heat treat combination for AOC large caliber

core production

II

II ,

Table 3. Program core blank - process correlation

Core blankidentification Program step

EL1 1EL6 1EL7 1EL8 1EL9 1EL10 1ELI1 5EL12 5EL13 5EL14 5EL15 5ELI6 5ELI7 5ELI8 5

EH 1 1EH6 1EH7 1EH8 1EH9 1EH10 1EH11 6EH12 6EH13 6EH14 6EH15 6EH16 6EH17 6EH18 6

NAl through NA20 Pilot lotNA21 1NA22 1

NCl 2NC2 2NC3 2NC4 2NC5 2NC6 2NC7 2NC8 2NC9 2NC12 3NC13 3NC14 3NC16 3

14

Core blank Program step

ident ificat ion

( NC17 3NC183NC19 3NC20 3

NC23 1NC24 1NC25 3NC26 3

ND1 3NC2 3ND3 3ND4 3ND5 3ND6 3ND7 3ND8 3ND9 3ND10 3ND11 3ND12 3ND13 3ND14 3ND16 3ND17 3ND18 3ND19 3ND20 3ND21 3ND22 3ND23 3ND24 3ND25 1ND26 1ND27 3

NEl 2NE2 2NE3 2NE4 2NE5 2NE6 2NE7 2NE8 2NE13 2

NE14 4NE15 4NE16 4NE17 4NE18 4NE19 4NE20 4

NE21 4

Core blankident ification Program step

NE 224NE234NE 24NE 254

NKI through NK23 Pilot lot

16

IclI

.,I a%4 0' r-ODNUC>w D14 CD m fl

U2 mm mmM 0 m3

En4

4) C;4U '0 4J

w4~ C(q -q '4r-1 - - -4 4 r-- 4 C'r--

w, (T ZJ.5. 00 O En eoe

a) 03 - NNr-4 r-4~- -NC4 (N 1

41

En ., 44- 0 4C4r r 4r N3Uq cn-

4J4

C4

:3 4

-4

0

0y 0 Q)310 ~4-4 - ..

1-4

03 --1 0 0

C14J

'--4

ko 00 ~ -

4-) . O "C> ( , -4 -W Zr'0 C

0 034 4 0 u to Lf0 0

f_).0. -4 zJ4z ZWZ 14W1 zzz ww

1 7

Table 5. Outgassing study (step 2) results

Coreblank Outgassing condition* Hydrogen results (ppm)ident. (2 x 10-5 Torr) avg.

NCI 600 0C (1100 0 F) 4 hrs. 1.0NC2 0.9NC3 0.8 0.87NC4 0.6NC5 1.0NC6 0.9

NE4 850 0C (1560 0 F) 2 hrs. 0.4NE5 0.3NE6 0.3 0.32NE7 0.2NE8 0.5NE13 0.2

NC7 850 0 C (1560 0F) 4 hrs. 0.1NC8 0.1NC9 0.2 0.15NEI 0.1NE2 0.2NE3 0.2

*vacuum outgassed at BCL, furnace cooled in argon

atmosphere

18

Table 6. Salt solutionizing - 1st iteration (step 3) results

outgassed: 4 hrs. at 850 0C (15600 F) <10-5 Torrsolutionized: 850 0C (15600 F) NaCl - KC1 salt

immersion rate: 46 cm/min.aged: 6 hrs at 370 0C (700 0F) lead pot

Trans- CenterCore Salt fer T e n s i 1 e Charpy lineblank residence time UTS Y.S. % KO hydrogenident. time (min) (sec.) (ksi) (ksi) elong. ksii-1n. (ppm)

ND10 10 15 - - - <0.lb

ND11 212.4 114.6 24.2 23.7a 0.5ND12 210.7 120.2 21.0 25.0a 0.3ND13 211.3 126.0 18.8 20.7a 0.4ND14 - - - 0 . 2 bND16 215.0 123.8 22.6 22.9a 0.5

NC12 10 25 210.7 122.4 25.0 32.5 0.6NC13 211.9 124.3 17.5 34.1 0.2NC14 212.7 124.7 22.3 31.0 0.2NC16 210.5 127.1 17.7 30.0 0.4NC17 -... 0.2 b

NC19 - - - - 0.2b

NC18 20 15 212.5 122.1 22.2 32.9 0.1NC20 - - - - O.IbNC25 - - - - 0 . 2 bND1 210.8 121.1 21.0 32.9 <0.1ND2 211.7 120.2 23.1 33.4 0.1ND3 210.8 127.0 16.9 32.2 <0.1

NC26 20 25 -... 0.9 b

ND17 208.3 122.7 15.7 30.1 0.1ND18 208.8 120.1 15.4 34.2 0.3ND18 -... 0.9 b

ND19 210.2 117.8 22.5 31.8 0.1ND20 205.4 120.8 15.2 33.8 0.3

ND4 30 15 210.8 123.2 24.2 26.1 0.3ND5 - - - -i b

ND6 - - - - O.ibND7 208.3 121.8 13.8 32.8 0.3ND8 214.1 124.7 20.6 2 5 .8 a 0.2ND9 211.5 125.3 17.8 31.2 0.7

ND21 30 25 213.0 122.8 20.6 31.9 0.3ND22 211.7 119.5 24.2 32.8 0.5ND23 209.8 121.4 23.8 33.7 0.2ND24 206.9 116.5 14.3 32.5 0.4ND24 - - - - 0.5b

ND27 .... 0.5 b

amaterial had poor microstructurebhydrogen sample obtained before aging the material

19

Table 7. Salt solutionizing - 2nd iteration (step 4) results

outgassed: 2 hrs. at 850 0C (1560 0 F) <10-5 Torrsolutionized: 850 0C (1560 0F) NaCI - KC1 salt

immersion rate: 46 cm/min.aged: 6 hrs. at 370 0C (700 0 F) lead pot

Trans- CenterCore Salt fer T e n s i 1 e Charpy lineblank residence time UTS Y.S. % K . hydrogenident. time (min) (sec) (ksi) (ksi) elong. ksxv"TW. (ppm)

NE14 20 15 210.6 117.3 18.6 31.3 0.4NE15 20 15 212.7 120.5 20.8 31.2 <0.1NE16 20 15 - - - - 0.4*NE17 20 15 - - - - 0.4*NE18 20 15 213.9 121.0 17.7 32.6 0.2NE19 20 15 209.5 120.1 17.3 31.9 0.2

NE20 20 25 208.2 119.6 20.5 35.2 0.2NE21 20 25 211.2 119.0 15.4 33.2 0.3NE22 20 25 - - - - 0.1*NE23 20 25 - - - - 0.3*NE24 20 25 213.7 124.1 17.4 33.8 0.2NE25 20 25 206.0 126.1 14.0 29.8 0.3

*hydrogen sample obtained before aging the material

20

Table 8. Comparison of total indicator reading (TIR)*data of solutionized M774 core blanks

Vacuum solutionizing vs. salt solutionizing

Vacuum (Sunbeam) SaltSample size 95 core blanks 12 core blanks

(random sample) (step 4 material)

Maximum TIR 0.82 0.16

Minimum TIR 0.03 0.03

Average TIR 0.27 0.11

Note: TIR was measured from tail end (numbered end).2nd V-block was located 14 inches from the ist V-blockstop, where tail end of core blank is positioned.

*all units in inches

21

Table 9. Verification tests (step 5) results

outgassed: 4 hrs. at 850 0 C (1560 0 F) <10-5 Torrsolutionized: 850 0C (15600 F) NaCI - KC1 salt

immersion rate: 46 cm/min.aged: 6 hrs. at 370 0C (700 0 F) lead pot

Trans- CenterCore Salt fer T e n s i 1 e Charpy lineblank residence time UTS Y.S. % K hydrogenident. time (min.) (sec.) (ksi) (ksi) elonq. ksiin (ppm)

ELI1 20 15 202.8 109.1 22.9 38.5 0.1EL12 20 15 200.7 109.4 22.5 36.2 0.1EL13 20 15 200.6 108.9 21.4 36.8 0.2EL14 20 15 202.3 108.6 22.3 37.4 0.1EL15 20 15 - - - - 0.laEL16 20 15 - - - - 0.laEL17 20 15 - - - - 0.1bEL18 20 15 - - - - 0.2b

aas-outgassed conditionbas-solutionized condition

22

' /

Table 10. Verification tests (step 6) results

outgassed: 4 hrs. at 8500 C (1560 0 F) <10-5 Torrsolutionized: 850°C (15600 F) NaCI - KCl Salt

immersion rate: 46 cm/min.aged: 6 hrs. at 370 0C (700 0 F) lead pot

Trans- CenterCore Salt fer T e n s i 1 e Charpy lineblank residence time UTS Y.S. %K hydrogenident. time (min.) (sec.) (ksi) (ksi) elong. ksi? . (ppm)

EH11 20 15 213.6 128.1 18.2 31.6 0.2EH12 20 15 211.5 124.2 16.8 31.1 0.1EH13 20 15 214.2 122.4 20.1 32.7 0.2EH14 20 15 213.1 121.3 14.4 31.6 0.1EH15 20 15 - - - - 0.2aEH16 20 15 - - - - 0.2aEH17 20 15 - - - - 0.lbEH18 20 15 - - - - 0.2b

aas-outgassed conditionbas-solutionized condition

A

23

f .... . .. I ' ' . .. - .. . . . .. .

Table 11. Pilot lot cores

outgassed: 2 hrs. at 850 0C (1560 0 F) <10-5

solutionized: 8500C (1560 0 F) NaCl - KCI saltfor 20 minutes

transfer time: 15 secondsimmersion rate: 46 cm/min.

aged: 6 hrs. at 370°C (700*F) lead pot

Pilot lot Core blank Hardnessblank no. identification Comment (Rc )

1 NAl2 NA23 NA3 High O.D. HRc 44.24 NA4 High O.D. HRc 44.55 NA56 NA67 NA7 High O.D. HRc 44.58 NA8 High O.D. HRc 45.89 NA9

10 NA1011 NAll12 NA13 High O.D. HRc 45.513 NA15 High O.D. HRc 44.514 NA16 High O.D. HRc 44.315 NA18 High O.D. HRc 44.416 NA1917 NA2018 NKI High O.D. HRc 44.819 NK220 NK321 NK422 NK523 NK624 NK725 NK826 NK927 NK1028 NK1129 NK1230 NK1331 NK1432 NKI533 NK1634 NK1735 NK1836 NK1937 NK2038 NK2139 NK2240 NK23

24

Pilot lot Core blank Hardnessblank number identification Comment (R

NA17 Machining rejectand high O.D. HRc 44.3

Mechanical property samples

CenterT e n s i 1 e Charpy lineUTS Y.S. % KO hydrogen

(ksi) (ksi) elong, ksil (ppm)

NA10 218.1 131.1 19.2 31.1 0.3NA14 216.3 127.3 20.3 30.7 0.7

25

I ' i - ' I1iII -. . .. -. ... .

FACILITIZATION FOR SALT SOLUTIONIZING HEAT TREATMENT

To incorporate salt solutionizing into the process stream oflarge caliber core heat treatment, several capital items would berequired. Essentially, this new stage of heat treatment wouldreplace the heat treatment now conducted by the AVS and Sunbeamsolutionizing furnaces. If salt solutionizing is implementedinto the production stream, the AVS and Sunbeam could be utilizedas outgassing furnaces to support this process. Whether or notthese pieces of equipment would be converted is not known andsubsequently not considered in this evaluation. The process andequipment specified is done so with the considerations that theinput to this new process would be as-blanked core blanks. Theoutput of this designed process would be solutionized coreblanks, free of salt, ready for the aging or straighteningprocess. Thus, the salt solutionizing process would require anew outgassing furnace, salt bath, quench tank and wash station.

The potential labor savings from the salt solutionizingprocess are estimated at approximately .057 hr./core. Associateddollar values are not presented here because of the sensitivityof that information. In addition, the dollar value is onlyapplicable to a specific manufacturing operation and would bemisleading if applied to another manufacturer.

The production rates used as design criteria are consistentwith the FY '83 mobilization option quantities of 10,000 M833 and4,000 XM829 cores per month each. These rates are achievedutilizing 70% of maximum equipment capability per 500 hours on a3/8/5 shift basis. At these rates and shift basis, the actualheat treating requirements for M833 and XM829 core blanks wouldbe 13,000 and 5,200 cores per month, respectively.

Outlined on the following pages are the required equipmentand general specifications. The specifications are those asdetermined by this study. Included with these specifications areequipment sources and cost figures obtained from quotationsreceived in forth quarter 1983.

-26-

Salt Solutionizing Process Equipment

Outgassing Furnace

Equipment Specification

Capacity: 17600 Kg (8000 lbs.)Vacuum Level: [10-4 TorrSoak Temp: 850 C (1560 F)Soak Time: 2 hrs.Total Cycle Time (load-unload): 5.5 hrs.

Source: AVS

Base system, diffusion'pumping $242Ksystem, cool down heat exchangersystem

Outgassing baskets IlK

2 baskets/furnace

Installation 40K

$293K

Salt Solutionizing Process

Process Specifications

Capacity: 80 blanks per hour (20 blanks perload)

Bath Temp: 850 CSalt Residence Time: 10 minutesImmersion Rate: 40-60 cm per minuteCycle Time: 15 minutes

Source: Upton

Complete system includingfixtures, quench tank, hoistsuperstructure, canopy,platforms, and installation $280K

$280K

Water Spray Area for Salt Removal $ 10K

Total $583K

-27-

.. . .( ... .... ,

Production Area

Erection of a 700 sq. meter $375K(7500 sq. ft.) facility includingelectric, plumbing and ventilationservice

Total Cost $958K

-28-

TABLE 12

SALT SOLUTIONIZING

CHEMICAL ANALYSIS

OF

HEATS TESTED

ELEMENTS HEAT

3357 3303 3295

Al <5 (:__l 5 5BA <5 < 5 < 5

Co <0. 6 (-' .b <0. 6Cr 5 5 5C 118 8 5

Fe 20 20 20

Mg <4 < 4 <4

Mn 6 7 7

Ni 6 5 8

Si 49 29 65

Ti .74 .78 .71

v < 5 < 5 <5Zn 00 <0C 45 23 44

29

DISTRIBUTION LIST

CommanderArmament Research and Development CenterU.S. Army Armament, Munitions and Chemical Command

ATTN: DRSMC-TSS(D) (5)DRSMC-LCU-M(D) (20)

Dover, NJ 07801

AdministratorDefense Technical Information Center

ATTN: Accessions Division (12)

Cameron Station

Alexandria, VA 22314

Director

U.S. Army Materiel Systems Analysis Activity

ATTN: DRXSY-MP

Aberdeen Proving Ground, MD 21005

Commander/DirectorChemical Research and Development Center

U.S. Army Armament, Munitions and Chemical Command

ATTN: DRSMC-CLJ-L(A)

DRSMC-CLB-PA( A)APG, Edgewood Area, MD 21010

Director

Ballistics Research Laboratory

Armament Research and Development CenterU.S. Army Armament, Munitions and Chemical Command

ATTN: DRSMC-BLA-S(A)Aberdeen Proving Ground, MD 21005

Ch i etBenet Weapons Laboratory, LCWSL

Armament Research and Development Center

U.S. Army Armament, Mur tions and Chemical CommandATTN: DRSMC-LCB- TLWatervliet, NY 12189

Commander

U.S. Army Armament, Munitions and Chemical Command

ATTN: DRSMC-LEP-L(R)Rock Island, IL 61299

30

Director

U.S. Army TRADOC Systems Analysis ActivityAttn: ATAA-SLWhite Sands Missile Range, NM 88002

Director

Industrial Base Engineering Activity

ATTN: DRXIB-MT (2)

Rock Island, IL, 61299

Project Manager

Tank Main Armament SystemATTN: DRCPM-TMA-Tf%Dover, NJ 07801

Commander

U.S. Army Munitions Production BaseModernization Agency

ATTN: DRSMC-PBM(D) (2)Dover, NJ 07801