Metallographic investigations showed that holding in a nitrogen--hydrogen--ammonia atmosphere at elevated temperature led to significant grain growth in the structure of the specimens and to the appearance of variations in grain size, confirming that recrystallization occurred. The change of the structure of the specimens was in good agreement with the change of their strength properties. The results of evaluation of the durability of specimens of copper M3 in moist nitrogen-hydrogen-ammonia atmospheres showed that the copper was corrosion-resistant under the given conditions. The rate of corrosion of the specimens throughout the tests was 0.00138 g/(m2.h). Taking into account that the operating time of industrial ammonia-synthesis columns is 5 years without catalyst reloadings and that reduction of the catalyst takes little time, we can say that copper is corrosion-resistant under the given conditions. Thus, the manufacture of unloaded parts of ammonia-synthesis columns from higher quality grades of copper is fully justified because in this case the rate of electrochemical corrosion will be still lower. LITERATURE CITED i. 2. 3. 4. 5.

A. N. Morozov, Hydrogen and Nitrogen in Steel [in Russian], Metallurglzdat~ Moscow (1963). V. B. Avarin, A. V. Revyakin, V. I. Fedorchenko, and L. N. Kovin, Nitrogen in Metals [in Russian], Metallurgiya, Moscow (1976). Ya, N. Vorob'ev, Corrosion Resistance of Materials in Corrosive Media of Chemical Processes [in Russian], Metallurgiya, Moscow (1975). A. P. Smiryagin, N. A. Smiryagina, and A. V. Belova, Industrial Nonferrous Metals and Alloys [in Russian], Metallurgiya, Moscow (1974). I. I. Novikov, Theory of Heat Treatment of Metals [in Russian], Metallurgiya, Moscow (1978).

THE TECHNOLOGY OF EQUIPMENT PRODUCTION A PRISMATIC FORM CUTTER FOR MACHINING A NEEDLE VALVE GATE B. Sh. Gasanov

U D C 621.9.025.11 621.646.9

For machining the outer-shaped surfaces of mass-production parts prismatic form cutters, which provide high productivity, stable accuracy, and uniformity in the shape and dimensions of the machined parts, satisfy requirements of interchangeability, simplify and ease the production of parts of complex form and fine profile, and make it possible to easily accomplish the operation of grinding and a large number of repair regrinds, are used~ In the All-Union Scientific-Research and Design Technology Institute for Petroleum Machinery Building there have been developed a prismatic face cutter equipped with a cutting prism of hard alloy and a new design of controllable tool holder, which have been introduced into the operation of form machining of the outer generatrix surface of the gate of a needle valve with D n = 6 mm produced in the Buniyat Sardarov Machine Building Plant. It is known [i] that in machining with a form cutter the specified form and dimensions of the machined part are provided by the profile of the cutting prism, the dimensions of which are calculated analytically in the tool design stage and are improved during its production. Based on the necessity of broadening the production and technological possibilites in preparation of the cutter and simplifying and easing the method of formation of the profile of the cutting prism, which has the contour portion of the profile with an undercut for machining the outer generatrix surfaces of the gate (Fig. i) of the needle valve, a compound design of prismatic form cutter was designed. It should be noted that the composition of the profile of the cutter of two cutting prisms with significantly simplified contour portions increases the production effectiveness of the cutting portion design and makes it possible to machine the profile of the cutting prism with nonshaped abrasive tools on simple production equipment (a universal surface grinder and a tool grinder) with the use of universal measuring instruments and production tools.

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 4, pp. 20-22, April, 1983.

162

0009-2355/83/0304-0162507.50

9 1983 Plenum Publishing Corporation

Plan of the needle valve gate.

Fig. i.

8~-$0 ' 10~f "~ _jB I

A ,~. ~ /

C

Fig. the

2.

25 5

Prismatic

outer

B-B (~urned,magnified)

~

o

75 +20

s

_/,oLf;,~ l.oo 9%~'

,

A-A

~

form cutter

generatrix

surfaces

.

for

machining

of a gate.

The prismatic form cutter (Fig. 2) is formed of two cutting prisms 1 and 2 brazed to the shanks 3 and 4, which are fastened with the help of the two cylindrical pins 5 and 6, The plane joining (abutment) of the cutting prisms and the shanks is located at an angle of 5 ~ , imparting an undercut to the cutting edge forming the face surface on area 2-3 of the gate (Fig. i). Overlapping of the plane of the face by the cutting edge is provided simultaneously with this. The calculated value of the overlap is 0.1515, which provides sufficient removal of the joint transition of the cutting edges on the face of the corner and thereby eliminates entry of the corner of joining of the cutting prisms into the cutting zone. The hard alloy plates were brazed on in such a manner that their KI and K2 (Fig. 2) projected by 0.5-1 mm beyond the limits of the planes Tz and T2 of joining of the shanks and then these projections were ground to blending (flush) with the planes TI and T2 at the same angle of the side undercut ~ T = 5~ and after this the shanks were assembled with the help of the pins. To provide free removal of the grinding wheel during grinding of the cutting prism profile the surface C--C of the shank was made 0,5-1 mm below the surface of the form profile of the cutting prism. The grooves GI and G= under the hard alloy plates, the supporting surface C--C located at an angle of 75 ~ , and the rectangular channeling with a spacing of 6 m~

163

turned

a

Fig. 3. Controllable tool holder with the prismatic form cutter used in machining the gate of a valve on a model IN318: a) design; b) external view. on the connecting portion of the cutter were ground after fastening the shanks with the pins. The leading surface of the cutter on the shank must be ground at an angle of ~c=~0+4~ ~, which prevents contact of the abrasive (diamond) wheel with the shank during grinding and finishing of the hard alloy cutting prism. It should be noted that grinding and regrinding of the cutter must be done only on the leading surface at an angle of 8 ~ and consequently in placing the cutter on the machine in the tool holder at an angle of ~o = 8 ~ the tool rake of Yo = 0 will be maintained automatically. At present in the operation of form machining of a gate of 20Kh13 steel for the cutting prism VK60M hard alloy with a titanium carbide coating supplied in the form of form $20 plates to Council for Mutual Economic Aid ST 118-74 has been introduced. The form profile P of the cutting prism is made by grinding on an optical profile grinder [i] with a mirror. As the cutting tool for grinding the profile of the hard alloy cutting prism AIT- and A2P 125•215 type ASP 50/40 100% B2 (GOST 16179-70) diamond wheels were used~ The grinding conditions were rate of rotation of the grinding wheel n w = 3500 rpm, number of double passes of the grinding spindle per minute ndp = 45, and transverse feed to the grinding wheel s t = 0.01 mm/double pass. The surface finish of the profile obtained corresponds to Class 8. The controllable tool holder (Fig. 3) for placement, control, and fastening of the prismatic form cutter consists of the housing 4, made with a groove sloped at an angle of 8 ~ , in which is located the cutter i on the 75 ~ dihedral angle of the shank (section A--A). On the back edge of the cutter are formed rectangular grooves (teeth) with a spacing of 6 mm engaged with the same teeth of the control lug 3, which permits stepped control of the height of placement of the cutting portion of the cutter relative to the line C--C of the center of machining. Micrometric regulation and accurate adjustment of the cutting edge of the cutter is done with the control screw 2 into the body of the control lug and at the same time resting against the flat of the pin 5, which is placed immoveably in the hole of the housing. In the adjusted position the cutter is fastened by the clamping screw 6, which is screwed into the

164

housing and r e s t s b y its tapered end on the V-shaped pyramidal section [3] of the control lug (Fig. 3~ section B--B). At four points the tool holder housing is fastened to the cross slide of the machine by sets of nuts 7, washers 8, and bolts 9, with the heads of the bolts located in T-shaped grooves. The gate blank being machined i0, a i2-mm diameter bar, is clamped in the collect chuck of the machine by its end after advancing 17 mm to the stop. The outer formed surface of the gate is turned with radial feed Sr of the cutter as the result of movement of the saddle, In reverse movement of the saddle the gate is cut off with a cutter located in the rear tool holder with the following cutting conditions: radial feed s r = 0.05 mm/rev; rate of rotation of the part np = 500 rpmo The cutting fluid was a 5% soluble oil solution. Long service of this tool set-up under production conditions has shown its high effectiveness. The tool holder design developed eases control and accelerates adjustment of the tool on the machine and provides highly productive machining of an average of i000 parts per shift and stable accuracy and quality of the machined parts, the gates. The finish of the machined gate surfaces is Class 6. LITERATURE CITED i. 2. 3~

G. I. Grabovskii and K. P. Panchenko, Form Cutters [in Russian], Mashinostroenie, Moscow (1975). I. I. Dashevskii, I. M. Burtsev, and A. M. Zakrevskii, Profile Grinding of M~chine and Instrument Parts [in Russian], Mashinostroenie, Moscow (1977). B. Sh. Gasanov, Inventor's Certificate No. 846119, "A prismatic built-up controllable cutter," Byull. Izobret., No. 26 (1981).

A NEW WASHING SOLUTION FOR DEGREASING PARTS AND ASSEMBLIES OF OIL-FILLED ELECTRIC MOTORS R. A. Dmitrieva, G. K. Kamalov, G. P. Malkina, and M. M. Tsepenyuk

UDC 621.7.024o67~4 621~

In the production and repair of submersible oil-filled electric motors, which are the drives of pumps for petroleum recovery, an organic solvent, white spirits, is widely used for degreasing the electric motor parts and assemblies. Although it is a good degreaser, white spirits has a number of significant disadvantages. Among the primary of these must be mentioned inflammability, which makes it necessary to conduct degreasing operations in special areas, toxicity, requiring the use of special measures for the protection of workers from the generally toxic and narcotic action of the solvent, the formation after degreasing of corrosion sources on the unprotected surfaces of parts and assemblies of ferrous and nonferrous (copper and its alloys) metals in between-operation storage as the result of the high hygroscopic properties of white spirits, and incomplete removal of mechanical contaminants as the result of the absence in white spirits of the capacity to hold them in the suspended concition. In addition, in operation a most important condition is elimination of the influence of residual films of the washing compound on the parts and assemblies after their degreasing and drying on the dielectric strength of transformer oil, with which the internal space of the electric motor is filled in testing and service~ As the result of the failure of action ofwashingsolutions on the protective coatings of parts and on nonferrous metals as the result of the high alkalinity of the solutions, the high temperature of the degreasing process (70-90~ the strong and stable foam formation, making possible mechanization and automation of the process difficult, and also the complexity of rendering harmless the used solutions before discharging into the sewer system, the use of known washing solutions is impossible.

Translated from Khimicheskoe i Neftyanoe ~shinostroenie,

0009-2355/83/0304-0165507.50

Noo 4, pp. 22-23, April, 1983.

~D [983 Plenum Publishing Corporation

165