SU1463788A1 - Die steel - Google Patents

Abstract

This invention relates to the field of metallurgy, in particular to nitriding. die steel and copper and copper alloys. The purpose of the invention is to increase the heat resistance of the nitrated layer at 600 ° C, resistance to the formation of high cracks after nitriding, toughness at 600 s and technological plasticity. The steel additionally contains barium in the following ratio of components, wt.%: Carbon 0.38–0.46, silicon 0.15–0.38, manganese 0.15–0.48, chromium 3.6–4, 4, molybdenum 0.9-1.2, vanadium 0.4-0.13, aluminum 0.12-0.42, titanium 0.005-0.1, boron 0.0008-0.008, calcium 0.005-0.05, barium 0.005-0.05, iron the rest. The content of calcium, barium, titanium and boron satisfies the ratios of calcium Q titanium. barium 0.9 ... 1.1,. 6.25 ... 12.5. The use of steel allows to increase the service life of the dies. 2 tab. i (Л С

Description

one

The invention relates to metallurgy, in particular, to an azotised, blunt steel for injection molds of aluminum and copper alloys, and can be used in metallurgy and engineering industry.

The aim of the invention is to increase the heat resistance of the nitrated layer at 600 ° C, to resist the formation of high-level cracks after nitriding, impact strength at 600 ° C and technological plasticity.

The chemical composition of the experiment melts are given in table.1.

The properties of steels are determined on samples; heat-treated in the following mode: quenching from 1040 ° C;

lo, tempering 69U ° C, 1, 5 h, second tempering 580 С, 1.5 h. Nitriding: 520 ° С, 16 h, the degree of dissociation of ammonia is 25-30%, 620 ° С, 0.5 h without; ammonia and 520 s, 4.5 hours without ammonia.

The resistance of formations of height cracks is estimated by the number of cycles before the appearance of the first crack when cycling through the 650 ° C mode: 20 ° C.

Technological plasticity is assessed by the number of revolutions until rupture samples with a working part diameter of 5 mm are destroyed before destruction at 1100 ° C.

Impact strength is determined by a standard procedure.

four

00 00

Heat resistance is evaluated by microhardness after heating up to, within 4 hours,

The results of the tests are given in table. 2

The test results indicate the advantage of the proposed steel with the best complex properties.

The smelting of iron-based direct reduction steel can significantly increase the efficiency of the mold — the number of cycles before the first cracks occur, which affects the quality of the products.

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Formulas

the invention

Stamped steel, mainly for nitriding, containing carbon, silicon, manganese, chromium, molybdenum, vanadium, aluminum, titanium, boron, calcium, iron, in order to increase the heat resistance of the nitrated layer

0

five

five

when, resisting the formation of cracks of the high peak after nitriding, of toughness under viscosity and technological plasticity, it additionally contains barium with the following content of components, wt.%:

Carbon

Silicon

Manganese

Chromium

Molybdenum

Vanadium

Aluminum

Titanium

Thief

Calcium

Vary

Iron

0.38-0.46 0.15-0.38 0.15-0.48 3.6-4.4 0.9-1, 2 0.4-0.8 0.12-0.42 Q , 005-0.10 0.0008-0.008 0.005-0.05 0.005-0.05 Else

moreover, the content of calcium, barium, titanium and boron satisfies the ratios m: Ca

On

0.9 ..., 1,

Ti

at

6.25 ... 12.5.

.:. s:: i.-ri-i-i7--; ±; lE Lgr

Table I

Claims (1)

Claim. At general content components, ma < Carbon 0.38-0.46 Silicon 0.15-0.38 Manganese 0.15-0.48 Chromium 3.6-4.4 Molybdenum 0.9-1, 2 Vanadium 0.4-0.8 Aluminum 0.12-0.42 Titanium 0. 005-0.10 Boron 0.0008-0.008 Calcium 0.005-0.05 Barium 0.005-0.05 Iron Rest predominantly containing carbon Stamp steel, for nitriding, rod, silicon, manganese, chromium, molybdenum, vanadium, aluminum, titanium, boron, calcium, iron, characterized in that, in order to increase the heat resistance of the nitrided layer