SU1633002A1 - Additive for alloying of steel - Google Patents

Description

The invention relates to a metaturgy, namely to master alloys for the odifpirovanie steels with enhanced characteristics of welding and technological properties.

The purpose of the invention is to improve the technological properties of steel and crack resistance during welding.

Experimental melts of ligatures were carried out in open induction furnaces. crucible with a capacity of 150 kg under fluorine flux by remelting. Calpium, sulfuric acid, sulfuric acid and ferroboron are introduced after melting the other components and refining the melt. The casting of ligatures is made into flat metal and granaries,

jInraTypy is tested when casting low-alloyed steel 32ГХ06Л, smelted in another furnace DS-5, when it is released from the furnace into the ladle. Cast ingots are forged into rods from which samples are made for mechanical and process testing and wire for surfacing and welding. The critical strain rate is determined by a known technique, and toughness is determined on samples of 10x10x55 mm with a V-notch.

and tab. Table 1 lists the compositions of the master alloys used to modify the steels of the experimental heats. 2 oe with co

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data and technological properties of the dispersed steels of the experimental heats. In the proposed ligature compared with the known manganese content is increased to 12-17 wt.%. The lower limit of the content of manganese is established from the need to increase the technological capacity, steel type, leveling of the structure and hardness. When the concentration of manganese is more than 12 wt.%, The tendency of steel to warping increases, white and the crack resistance decreases.

The lower limits of the concentration of carbon (0.2 wt.%) And silicon (6 wt.%) J are set to prevent the formation of hot cracks during welding, a high content of eutectic cementite in the structure, ensuring high resistance to distortion, crack resistance. The upper limits of the carbon content (1.0 wt.%) And silicon (10.0 wt.%) Are due to an increase in the heterogeneity of the structure, a decrease in the technological plasticity and welding-2 of the technological properties at higher concentrations.

Nickel in the amount of 12-27 wt.% Increases the crack resistance during casting, welding and surfacing and resistance to intercrystalline corrosion, reduces the tendency to warping and increases the resistance to grazing. When the nickel concentration is up to 12% by weight, the technological plasticity and endurance resistance are insufficient, and with an increase in the nickel concentration of more than 27% by weight, the resistance to hot cracks decreases and the tendency to distortion increases.

Cerium (3-7 wt.%) And titanium (2 to 5 wt.%) Increase the modifying capacity of the ligature, grind the grain in the modified steel and increase the technological plasticity at a cerium concentration of up to 3 wt.% And titanium to 2 wt.% . The modifying effect of the ligature and the technical properties of the steel are insufficient, and with an increase in their content above the upper limits, the crack resistance and the uniformity of the structure and properties of the steel and its hot plasticity decrease. Carbon reduces the technological plasticity and welding-technological properties; therefore, its content is limited by a concentration of 1.0 wt.%. The nitrogen content in the amount of 2-6 wt.% Increases the resistance of the stag. And to bulging, essentially

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but not reducing welding and technological swaps.

The additional introduction of copper crushes the structure of the steel in the casting and in the weld, contributes to the increase of hot plasticity and welding-technological properties. At a copper concentration of up to 8 wt.%, Resistance to the formation of hot cracks, scuffing under friction and hotness, plasticity is insufficient, and at a copper concentration of more than 12 wt.%, The uniformity of steel and its welding-technological properties decrease.

Calcium cleans the grain boundaries, has a deoxidizing effect and increases the welding-technological properties. The upper limit of calcium concentration (7 wt.%) Is due to its insufficient dissolution in steel and a decrease in resistance to intergranular corrosion, and the lower limit (3 wt.%) Is due to a decrease in deoxidation and pair-technological properties.

The introduction of boron due to its high modifying and chemical activity, increases the homogeneity of the structure and properties of steel. When it is contained in a ligature of up to 2 wt.%, The effect is insufficiently affected, and at a concentration of more than 6 wt.%, Crack resistance, impact toughness and hot plasticity are reduced.

As can be seen from the data presented in table. 2, the use of the proposed ligature for the modification of steels provides for an increase in the technological properties and the crack resistance during welding more than the known ligature.

Claims (1)

Invention Formula The ligature for steel containing chromium, nickel, silicon, manganese, titanium, nitrogen, carbon, cerium and iron, characterized in that, in order to improve the technological properties of steel and crack resistance during welding, it additionally contains copper, calcium and boron in the following the ratio of components, wt.%: Chrome 12-22 Nickel12-27 Silicon6-10 Manganese12-1-7 Titan2-5 Nitrogen 2-6 0.2-1 3-7 8-12 3-7 2-6 Else Table f 9 1211 s table 2 1130 1320 1380 830 13.5 14.8 14.6 11.4 9.5 10.7 10.5 7,8