ALLOYED CAST STEEL AND ARTICLE MADE THEREFROM

Abstract

Disclosed is structural low-alloy manganese cast steel having increased hardness and wear resistance, and an article made therefrom. In particular, after carrying out conventional bulk hardening followed by tempering, the disclosed steel has hardness of approximately 418 to 512 HB and is suitable for use in railway engineering, in particular for manufacturing parts of freight car trucks such as a friction wedge. Due to improved hardness and wear resistance of the parts made of the steel according to the present invention, an increase in inter-repair service life, in particular, of the friction wedge/friction plate friction pair is provided without a significant increase in cost for the parts.

Claims

1. Alloyed case steel characterized by the following content of elements (wt. %): TABLE-US-00003 Carbon (C) 0.27 to 0.35 Manganese (Mn) 1.20 to 1.40 Silicon (Si) 0.60 to 0.80 Chromium (Cr) 0.10 to 0.25 Aluminium (Al) 0.02 to 0.05 Vanadium (V) 0.015 to 0.040 Phosphorus (P) no more than 0.030 Sulfur (S) no more than 0.030 Nickel (Ni) no more than 0.30 Copper (Cu) no more than 0.30 Molybdenum (Mo) no more than 0.08 Iron (Fe) the remainder wherein the complex alloying coefficient CE for said steel calculated as
CE=C+(Mn+Si)/6+(Cr+Mo+V)/5+(Ni+Cu)/15 is no less than 0.68% wt.

2. Alloyed cast steel according to claim 1, characterized in that its hardness after bulk hardening followed by tempering ranges from 418 to 512 HB.

3. An article made of the steel according to claim 1 by casting.

4. The article according to claim 3, characterized in that the article made of the alloyed cast steel is a friction wedge of a freight car truck.

5. An article made of steel according to claim 2 by casting.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 shows surface hardness of a part (a friction wedge made of steel according to the present invention) obtained after heat treatment (bulk hardening with tempering) as a function of the complex alloying coefficient CE of said steel calculated as

CE=C+(Mn+Si)/6+(Cr+Mo+V)/5+(Ni+Cu)/15.

DETAILED DESCRIPTION OF THE INVENTION

[0010] Comparative tests were carried out in order to determine hardness values for samples made of the steel according to the present invention as compared to the prior art materials used for manufacturing friction wedges: grey cast iron class 25 and steel grade 20GL. The test results are shown in Table 1 below.

TABLE-US-00002 TABLE 1 Hardness, HB Steel according to the invention 418-512 Grey cast iron class 25 197-260 Steel 20GL 140-180

[0011] Brinell hardness measurements for the samples were carried out in accordance with the following procedure.

[0012] GOST 9012-59: Metals. Brinell method for measuring hardness.