SU1447917A1 - Iron-base alloy - Google Patents

Abstract

The invention relates to the metallurgy of alloys for the manufacture of tools used in the deformation by extrusion of products from aluminum and its alloys. The purpose of the invention is to increase the tensile strength and hardness while reducing the fragile aluminized layer formed during the extrusion of aluminum and its alloys. The alloy contains, wt%: carbon 1.8-2.8 molybdenum 1.1-3.0; chromium 8.0-9.5; vanadium 6.0-7.5; silicon-1.8-3.5} manganese 0.5-2.5; Nickel 2.0-3.7; boron 0.01-0.2; iron else. The alloy has the following properties: i d 640- 685 Sha, XI 62-71 kJ / m, HRC 61-65, the depth of the aluminized layer is 0.005-0.01 mm. 1 tab. (ABOUT

Description

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The invention relates to metallurgy, in particular, to the development of alloys for the manufacture of tools used in the processing of metals from aluminum and its alloys.

The purpose of the invention is to increase the strength, hardness while reducing the fragile alitin layer.

The proposed iron-based alloy contains components c. The following ratio, wt.%:

Carbon 1.8-2.8

Silicon 1.8-3.5

Manganese 0.5-2.5:

Chrome8.0-9, T

. Molybdenum 1.1-3.0

Vanadium 6.0-7.5

Nickel 2.0-3.7

Bor0,01-0,2

Iron Else

The carbon content above the specified upper limit increases the amount of carbides in the sapava structure, which reduces viscosity, reduces the ability to withstand impact strikes and impairs machinability. When the carbon content is less than the lower limit, the amount of carbides decreases, their shape changes, and the strength of the metal base shines, which adversely affects the performance properties of the alloy.

Molybdenum in the specified limits suppresses the formation of perlite upon cooling the part, which increases the strength of the metal matrix and improves the hardenability of the alloy. Moisture effect; molybdenum on the properties of the alloy affects when it contains more than 1, -1%. An increase in the molybdenum content of more than 3% does not lead to a significant change in the properties and

microstructure of the alloy.

The presence in the composition of the chromium alloy within the specified limits provides the optimum amount of the carbide phase and increases its microhardness.

Vanadium. Contributes to the formation of 50 vanadium carbides. The vanadium content above the upper boundary leads to the formation of carbides of the type (Cr, V) in the alloy structure, which reduces wear resistance; With a decrease in the content of 55 vanadium below 6.0% during crystallization, the form of an avtaktiki is predominantly formed, which contains, in addition to vanadium carbides, Me7C, which leads to

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five

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reduction of impact toughness and operational properties of the alloy.

Silicon within the specified limits ensures the fluidity of the alloy, promotes the formation of carbides and the conversion of stable austenite to martensit after quenching.

The presence of manganese within the specified limits stabilizes the content of residual high-alloyed austenite after heat treatment in the optimal amount. When its content is less than 0.5% in the alloy structure, the proportion of metastable austenite decreases, which increases brittleness and reduces the resistance of the alloy. The manganese content above the upper limit leads to an increase in the amount of stable austenite and a decrease in wear resistance.

Nickel expands the r-region, suppresses pearlite transformation and contributes to the strength of the metal matrix. At the same time, the diffusion of aluminum is significantly reduced and the depth of the diffusion intermetallic layer formed by the friction of the alloy on aluminum decreases. When the nickel content is below the lower limit of a noticeable decrease in diffusion. no layer is observed. Exceeding the upper limit of the drive | t to the deterioration of workability, alloy cutting. -Bor contributes to the grinding of the carbide phase, its uniform distribution and the increase in microhardness,

The effect of boron on the microhardness of the carbide phase appears when its content is more than 0.01%. With the introduction of boron more than 0%, the content of borides increases, which leads to an embrittlement of the alloy and a decrease in operational durability.

The positive effect of nickel and boron is associated with an increase in the hardness and degree of grinding of carbides, an increase in the strength of the metal base, which prevents the brittle diffusion layer from being pressed under high working pressures and reduces the likelihood of surface cracks.

Example. In order to study the structure and properties of the proposed alloy, alloys of the proposed composition were melted with different content of ingredients and known composition with an average content of components.

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The smelting of alloys is carried out in an induction furnace with a capacity of 30 kg with the main crucible. The components are introduced into the melt at a temperature of 1450-1500 C in the form of ferroalloys. Filling in dry sandy - clay forms is carried out at 1380-1430 ° C, billets with a diameter of 55 mm were cast.

The billets are annealed according to the mode: heating up for a time of 1.5 h and cooling with a furnace. After annealing / hardness was no higher than HRC 30,

After turning, the test specimen is subjected to heat treatment according to the following conditions: quenching from 1170 in industrial oil and double tempering from 520–540 ° C with a holding time of 30–40 min.

A hardness of 61-65 HRC is achieved. Then the sample from the studied alloy is adjusted by grinding to the desired size.

According to the described technology, prototypes are manufactured from the proposed and known alloys and their comparative tests are carried out on the SMC-2 friction machine. The pad is made of. Aluminum alloy AL-4. A disk - from the studied alloy. The working surface of the disk is ground and then polished to a purity of no less than 63.

Test results on the friction machine, as well as chemical composition

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and the mechanical properties of samples from the proposed 1-3 and 4 known alloy compositions are given in the table,

The table shows that the proposed alloy with the remaining has higher values of the complex of mechanical properties that determine its operational durability - the limit

0 strength and hardness.

Claims (1)

Formula An iron based alloy is predominantly for a tool intended for the manufacture of aluminum and its alloys by stamping, containing carbon, silicon, manganese, chromium, molybdenum, vanadium, nickel 0, and boron, characterized in that hardness while reducing the fragile aluminized layer, it contains the components in the following ratio, 5 wt.%: 0 Carbon Silicon Manganese Chromium Molybdenum Vanadium Nickel Boron Iron 1.8-2.8 1.8-3.5 0.5-2.5 8.0-9.5 1.1-3.0 6.0-7.5 2, OGZ, 7 0.01-0.2 Rest Prev Gaesh .. .. i. Vortex 1, 8,006,00 t, 80 0,50 2,00 0,0t Hairpin 640 7t «t 0.01 - Voyot 1170, 1190 ° С 8 butter g Average 2.30 2.05, TZ 2.65 t.50 2.6S 0.105 - -2-klltl 66S 6863    . Holiday from - 520-540 С  .ti saaaa 2.80 3.00 9.50 7.50 3.50 2.50 3.70 0.92 - -30-40 mt 685 6265 0.005 ftsre- . ... etty 4 Average 3.3 t, 11 0.350.25 1.12 0.84 1.130.22. Zmsalkv 570 6252 С, 015 ..from 1170.; -. 1190 ° C  . .. butter  CtgMpcHiHii met 1.11JHtpaTtM    -.,. vacation from -. .530-5 "and with. 30-40 m