SU908924A1 - Foundary martensite steel - Google Patents

Description

t

The invention relates to metallurgy, and in particular to martensitic stainless steels for shaped castings with a high level of casting, mechanical and operational properties.

Closest to the present invention is foundry martensitic steel 09X16H4BL1, containing wt.%:

0.05-0.13

Carbon

0.20-0.60

Silicon

0.30-0.60 "

Manganese

15.0-17.0

Chromium

3.50-4.50

Nickel

0.05-0.20

Niobium

No more than 0, PZ

Copper

Not more than 0.025

Sulfur

No more than 0.03

Phosphorus

Rest

Iron

The disadvantages of the known steel are relatively low casting and mechanical properties.

The purpose of the invention is to increase the complex of foundry and mechanical properties.

The goal is achieved by the fact that cast martensitic steel containing carbon, silicon, manganese, chromium, nickel, niobium, copper and iron, additionally contains aluminum, titanium, calcium and rare earth metals in the following ratio of components, wt.%:

0.05H), 13

Carbon 0.20-0.60

Silicon 0.30-0.60

Manganese 15.0-17.0

Chrome 3.50-4.50

Nickel 0.05-0.20

Niobium 0.10-0.30

Copper 0.01-0.05

Aluminum 0.01-0.08

Titanium

Kalsh1y 0,005-0,05

Rare earth

0.005-0.08

Metals Else

Iron

The additional introduction of aluminum, titanium, calcium, and rare-earth metals into the composition is explained by their exceptionally complex beneficial effect on its casting and mechanical properties. Being strong deoxidizing agents and modifiers, these elements improve the fluidity and crack resistance of castings, clean the grain boundaries from harmful impurities, provide a globular shape of non-metallic inclusions. The total content of inclusions and sulfur in steel is reduced by almost 2 times. These factors ultimately contribute to the improvement of the casting properties, and especially the ductility and toughness of steel. At the same time, aluminum and titanium neutralize the harmful effects of free nitrogen on the properties of the steel, linking it to refractory nitrides. To determine the optimum composition of the steel, experimental melting was carried out and its casting and mechanical properties were investigated depending on the different content of the components. The steel is melted into 160 kg of an induction furnace by remelting. In the case of fractional casting, the steel is modified. additives 0.1-0.5% ligatures containing calcium, rare-earth metals, niobium, aluminum, titanium and nickel. 4 The chemical compositions of the experimental steels are given in table. one; in tab. 2 - casting and mechanical properties of steel. From the above results it follows that the steel of compositions N ° 2-6 exceeds the known steel in the whole complex of the properties studied. Experienced steel compounds No. 7 and 8 does not have an advantage over the famous steel. This allows us to conclude that the proposed steel No. 2-6 has an optimal composition and is recommended for industrial use in the aviation, chemical and other industries in the manufacture of parts with increased strength, ductility and toughness. The steelmaking technology of the proposed steel does not differ from the known steel 09X16H4BL. Some difference lies in the modification of steel with a nonsiloxane complex ligature containing calcium, rare-earth metals, aluminum, titanium, niobium, and nickel. Modification is carried out with the release of steel from the melting unit into the casting ladle, which does not require additional devices.

Table 1

Table 2

Claims (1)

Claim Foundry martensitic steel containing carbon, silicon, manganese, chromium, nickel, niobium, copper and iron, characterized in that, in order to improve the complex of casting and mechanical properties, it additionally contains aluminum, titanium, calcium and rare earth metals in the following ratio of components , weight.%: Carbon 0.05—0.13 Silicon 0.20—0.60 Manganese 0.30-0.60 Chrome ’ 15.0-17.0 Nickel 3.50-4.50 Niobium 0.05-0.20 Copper 0.10-030 Aluminum 0.01-0.05 Titanium 0.01-0.08 Calcium Rare earth 0,005-0,05 ' metals 0.005—0.08 Iron Rest 40