SU996503A1 - Iron-based alloy - Google Patents

Description

furnace in a crucible with a capacity of 160 kg with acid lining.

The following materials are used as batch materials.

Intermediate product of the Chusovskoy metallurgical plant with the content,%: coal-, genus 4.7% ;: sulfur 0, phosphorus 0.018%; manganese 0.02%; chromium 0.09%; the rest of the iron TU14-15-42-77. Nickel brand Hi GOST 849-70. Copper brand Ml GOST 859-78. Ferromanganese carbon. , dist. GOST 4755-70 with the content,%: manganese 94.1, carbon 2.3, sulfur 0.007. Ferrosilicon FS75 GOST 1415-78 with a silicon content of 87.7%, carbon 0.01%. Low-carbon steel grade E-12 GOST 11036-75. Mischmetall 15 .cerium MTs40 TU48-4-280-79. Aluminum grade A98 GOST 11069-74.

Ferrosilicon is injected into the alloy in 2 steps: 30% by weight at the beginning of smelting, and 70% at the end. Misch metal is injected under the stream of alloy

To stabilize the sizes of the samples and castings due to the equilibrium distribution of carbon in the alloy structure, the parts undergo the following heat treatment: annealing for 1-1.5 hours at 1000 ° C and cooling with a furnace.

These materials, smelting and heat treatment techniques are used for all parts and samples.

In tab. 1 shows the chemical composition of the described alloy and known.

T a

faces

By comparison with a binary-alloyed lime-iron-nickel element introduced, it increases its thermal expansion coefficient to a predetermined value. The role of α-rare earth metals (CPMS) is in spheroidism. inclusions of graphite in the alloy necessary to increase the thermal expansion coefficient. Carbon and silicon provide good casting properties of the alloy. In addition, silicon acts as a graphitizer, which is important from the point of view of preventing the alloy from being deflected in the event of its rapid cooling.

The indicated limits for the content of elements in the alloy are chosen in connection with the following circumstances. An increase or decrease in nickel content leads to an increase in thermal expansion coefficient over the permissible limits. A decrease in the carbon content leads to a deterioration in the fluidity of the alloy and a decrease in its TCLE. Excess content

carbon creates a non-uniform distribution of inclusions of graphite over the height of the casting due to its rise to its upper parts and an increase in thermal expansion coefficient over the permissible limit. A decrease in the silicon content impairs the fluidity of the alloy and decreases its thermal expansion coefficient, and an increase in - leads to an excess of the acceptable thermal expansion coefficient and an increase in the carbon equivalent of the alloy to. hypereutectic meaning that causes float graphite. A decrease or increase in the content of manganese and copper leads respectively to a decrease or increase in the thermal expansion coefficient of the alloy beyond the allowable limits. A decrease in the SEM content does not ensure the complete spheroidization of graphite in the alloy structure. Excess SEM content causes the appearance of lamellar graphite in the alloy structure, due to the effect of remodification. The main components of the proposed alloy: iron; nickel; carbon; silicon) manganese; copper and rare-earth metals; the remaining elements are impurities. Obtained from smelting number 5 by charging, nickel in the furnace. Obtained from smelting No. 2 by refining nickel in the furnace. The developed alloy possesses high treadinostability and fluidity, has a nickel content interval sufficient for stable production of the alloy in low-tonnage furnaces of foundries and instrument-making devices. Known Probe 46N IPL Offered 1 Е 1st 1st Same Casting 1540 Known. Proposed Ditto - -1390 Ditto II - -1390 Casting1540 Known 4bN. № 2

To determine the crack resistance of smelted alloys, samples with a diameter of 140 mm are made, with a bulk wall of 8 mm and a height of 120 mm. In addition, experienced castings are poured: weight. 740 g, overall dimensions 130 x 60 x 60, minimal wall 4 mm, 2, weight 2650 g, overall dimensions 210 x 150 x 110, where the minimum wall is 5 mm. Sample and castings are made by casting on melted etojM model m.

The described alloy (Table 2) significantly exceeds the known alloy in crack resistance. I To estimate the second parameter characterizing the foundry properties of the liquids Table

spill resistance, use a spiral sample, made in sandy-clay form. The conditionally true fluidity is determined at the same amount of superheating of the metal above the liquidus temperature. According to the previously obtained temperature

the liquidus of the described alloy is, and the liquidus temperature of the 46H alloy is 1420 ° C. Thus, samples for fluidity are poured at an equal superheating temperature above the liquidus temperature of 120 ° C.

In tab. 3 shows the conditionally true fluidity of the proposed and known alloys.

65 companies. the composition of the alloy provides the required TCLE (7,, 75) 10-deg-L table. 2 shows the crack resistance of the proposed and extruded alloys. In all samples, cracks 10-28 mm long were found. No cracks were found. On 12 castings, cracks were found on a 4 mm thick wall section located between two massive assemblies. No cracks were found. Same On 2 castings found on one through crack, on 2 castings of two

Table 3

Claims (3)

Claim . Iron based alloy containing 40 nickel, carbon, silicon, manganese, characterized in that, in order to improve the casting properties and reduce the cost, it additionally contains copper and rare earth metals in the following ratio of components, wt.%: . The TECL of the proposed alloy averages (7.5 + 0.75) · 10 ~ ⁶ deg ^-1 which is necessary from the point of view of design considerations. Compared with the known alloy, the described is cheaper, due to the lower (10%) nickel content. The introduction of additional elements in spyava elements has a lower cost than nickel Nickel Carbon Silicon Copper Manganese Rare earth 35-37 2.1-2.5 1.0-1.5 3.0-3.6 3.0-3.6 metals 0.04-0.40 Iron Else