SU1177379A1 - Two-phase ferritic-martensitic steel - Google Patents

Abstract

TWO-PHASE FERRITE-MARTEN SITNAYA STEEL, containing carbon, manganese, silicon, chromium, aluminum, sulfur and iron, characterized in that, in order to increase the hardenability after heating in. The intercritical temperature range of 740-830 ° C, increased technological plasticity and isotropy after cold hardening, it additionally contains one or more elements from the group containing titanium, zirconium and rare-earth metals i in the following ratio of components, wt.%: Carbon 0.04-0.12 Manganese 0.7-2.3 Silicon 0.05-0.9 Chrom0.3-1.5 Aluminum 0.03-0.08 Sulfur, 0.003-0.015 one or more elements from the group, containing I Titanium 0.03-0.12 Zirconium 6.0 3-0.12 (L Rare-earth metals 0.005-0.1 Iron Rest and the total content argantsa, silicon and chromium is 2,2-4,7% by weight, and the ratio of the content of one or more elements from the group comprising titanium, tsirkoCh Nij and rare earth metals to COCO holding sulfur is 4-15;. of

Description

1 The invention relates to ferrous metallurgy, in particular to two-phase ferritic-martensitic steels, intended for cold forming, extruding and unloading. The purpose of the invention is the increase in the caliber of steel after heating in the intercritical temperature range of 740-830 ° C, the decrease in technological plasticity and isotropy after cold strengthening. Example. In an induction furnace with a capacity of 60 kg, melts of steel with a weight of 50 kg are melted, ingots are forged into billets of square section with a side of 48 mm, and then rolled to a size with a diameter. 23 mm, after which a drawing is drawn to a predetermined size. Heat treatment is carried out in a chamber electric furnace and in a roller gas oven through passage in the mode: heating to 92 740-830 ° C, holding 10-30, min, cooling in water, The mechanical properties of the steel are determined on samples of cylindrical section with a diameter of 5 mm and 50 mm working part cut from rods with a diameter of 16 mm and on a wire with a diameter of less than 10 mm. To determine the level of technological properties during cold forging, heat-treated samples are subjected to cold elastic deformation (calibration) with a reduction of 10 and 30%. ivaemosti determined by the end face quenching, Table 1 shows the compositions of the proposed steel, steel compositions, departing from the limits of the proposed contents of the components and composition of the known steel, while Table 2 shows the properties of these steels. Table 1

Table 2

Continuation of table 2

Claims (1)

TWO-PHASE FERRITE-MARTEN 'MESTER STEEL containing carbon: manganese, silicon, chromium, aluminum, sulfur and iron, characterized in that, in order to increase hardenability after heating in the intercritical temperature range of 740-830 ° C, to increase the technological ductility and isotropy after cold hardening, it additionally contains one or more elements from the group consisting of titanium, zirconium and rare earth metals ₍ in the following ratio of components, wt.%: Carbon 0.04-0.12 Manganese 0.7-2.3 Silicon 0.05-0.9 Chromium 0.3-1.5 Aluminum 0.03-0.08 Sulfur 0.003-0.015 one or more items from group containing Titanium 0.03-0.12 Zirconium 0.03-0.12 Rare earth metals 0.005-0.1 Iron Rest • moreover, the total content of manganese, silicon and chromium is 2.2-4.7 wt.%, And the ratio of the content of one or more elements from the group containing titanium, zirconium and rare-earth metals to the sulfur content is 4-15. SU .. „1177379 1 1177379 2