SU1527311A1 - Steel - Google Patents

Abstract

The invention relates to the field of metallurgy, in particular to structural steel of increased strength, which is welded, and is intended for use in construction and mechanical engineering in the form of rolled plates (thickness up to 80 mm) manufactured at ferrous metallurgy plants for welded metal structures designed to operate at temperatures up to (-60) ° C. The purpose of the invention is to increase the hardenability, strength characteristics while maintaining the level of plasticity and satisfactory impact toughness at temperatures down to (-60) ° C, reducing the tendency to reversible temper brittleness. Steel acquires the possibility of cooling in air after high tempering, which leads to a hardening of heat treatment. Steel additionally contains vanadium in the following ratio of components, wt.%: Carbon 0.06-0.12

chromium 2.3-3.0

manganese 2.5-3.4

titanium 0.02-0.1

aluminum 0.01-0.05

rare earth metals 0.02-0.05

vanadium 0.04-0.08

iron else. The use of the proposed steel will allow the use of welded structures at service temperatures up to (-60) ° C and cross sections up to 80 mm, reduce the weight of structures by 30%, and also eliminate the need to cool products after high-temperature tempering in water or in oil. 2 tab.

Description

The invention relates to metallurgy, in particular, structurally welded steel of increased strength, TVi, and is intended for use in construction and mechanical engineering in the form of thick plates (thickness up to BO mm) manufactured at ferrous metallurgy plants for welded metal structures intended for operation. at temperatures up to -60 C.

The purpose of the invention is to increase the hardenability, strength characteristics while maintaining the level of ductility and satisfactory impact strength, reducing the tendency to reversible temper brittleness at temperatures down to -60 ° C.

Steel acquires the possibility of cooling in air after high tempering, which leads to a simplified thermal treatment.

in an induction furnace, three melts weighing 25 kg were melted. The ingots cooled in the sand and forged on a square of 70 mm. Then, hot rolling was carried out to a section of 16x100 mm. The heat treatment of the plates was carried out according to the following scheme: normalization (air cooling from 950 -), then desalting at 650 ° C, 2 hours with cooling in water and air.

The chemical composition of the bottoms is given in table 1, the mechanical properties in table 2.

As impurities, the steel may contain, wt%:

Phosphorus Up to 0.02 Sulfur C-0, 02 Silicon 0.15-0.4

 The hardenability of the proposed steel is up to 80 mm, of known steel is up to 60 mm.

The weldability of the proposed steel is satisfactory, similar to that of the known steel, but it allows welding steel up to 80 mm thick.

The application of the proposed steel will allow the use of welded structures with & N / mm at a temperature

114

In order to reduce the weight of structures by 30%, eliminate the need for cooling products after high-temperature tempering in water or in oil.

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five

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five

Claims (1)

Invention Formula Steel containing carbon, chromium, manganese, titanium, aluminum, rare earth metals, iron, characterized in that, in order to increase hardenability, strength characteristics while maintaining the level of ductility and satisfactory toughness, reduce the tendency to reversible temper brittleness temperatures up to -60 ° C, it additionally contains wyadium in the following ratio of components, mc.%: Carbon Chromium Manganese Titanium Aluminum Rarely 3 emelnye metals Vanadium Iron 0.06-0.12 2.3-3.0 2.5-3.4 0.02-0.1 about 01-0.05 0.02-0.05 0.04-0.08 Else Table 1 table 2