SE547320C2 - Big block of hot work tool steel and large mould for mega- and giga-casting - Google Patents

Abstract

The invention relates to a big block of hot work tool steel and/or a large mould of hot work tool steel for casting large structural parts, wherein the block and/or mould has a thickness of at least 200 mm, a length of at least 1000 mm and a width of at least 400 mm and/or the sum of the thickness, length and width of the block and/or of the mould is at least 2000 mm and wherein the hot work tool steel is obtainable by ESR and comprises the following main elements in weight %:C 0.28 - 0.39Si 0.05 - 0.35Mn 0.1 - 0.8Cr 5.4 - 6.0Mo 1.8 - 2.5V 0.6 - 1.1balance iron and impurities.

Claims (2)

A big block of hot Work tool steel and/or a large mould of hot Work tool steel for casting large structural parts, Wherein the block and/ or mould has a thickness of at least 200 mm, a length of at least 1000 mm and a Width of at least 400 mm and/or the sum of the thickness, length and Width of the block and/or of the mould is at least 2000 mm and Wherein the hot Work tool steel is obtainable by ESR and comprises the following elements in Weight %: C 0.28 - 0.39 Si 0.05 - 0.35 Mn 0.1 - 0.8 Cr 5.šš~¿g§-__- 6.0 Ni " Mo V AN P Cu CO E W iNb í 0.balance Fe apart from impurities. The big block and/or the large mould for casting large structural parts as defined in claim 1, Wherein the hot Work tool steel comprises one or more of the following elements in Weight %: C 0.33 - 0.37 Si 0.15 - 0.Mn 0.4 - 0.Cr 5.5 - 5.7 Ni E 0.25 M0 2.0 - 2.2 V 0.75 - 0.85 A1 0.001 - 0.03 N E 0.E 0.001 P E 0.010 Cu E 0.12 Co E 0.1 W E 0.1 Nb E 0.balance Fe apart from impurities. . The big block and/or the large mould for casting large structural parts as defined in claim 1 or 2, Wherein the sum of the thickness, length and Width of the block and the mould is at least 2500 mm, least 3000 mm or at least 3500 mm and/or, Wherein the mould has a Weight of at least 5 tons, or at least 10 tons, or at least 15 tons or at least 20 tons. . The big block and/or the large mould for casting large structural parts as defined in any of the preceding claims, Wherein the hot Work tool steel comprises one or more of the following elements in Weight %: C 0.34 - 0.36 Si 0.20 - 0.Mn 0.45 - 0.Mo 2.05 - 2.Ni E 0.V 0.77 - 0.N 0.001 - 0.P E 0.008 S E 0.0007 Cu E 0.The big block and/or the large mould for Casting large structural parts as defined in claim any of the preceding claims, Wherein the content of Mo and V in the hot Work tool steel is adjusted to fulf1l the requirement Mo/V = 2.3-3.0, preferably 2.5-2. The big block and/or the large mould for casting large structural parts as defined in claim any of the preceding claims, Wherein the cleanliness fulf1ls the following maximum requirements With respect to micro-slag according to ASTM E45 -97, Method A: A B B C C D D H T H T H T H

1. 0 1.5 1.0 0 0 1.5 1. The big block and/or the large mould for casting large structural parts as defined in any of the preceding claims, Wherein the steel is in the soft annealed condition, has a mean hardness of i 230 HBWm/aooo, has a thickness of at least 100 mm and Wherein the maximum deviation from the mean Brinell hardness Value in the thickness direction measured in accordance With ASTM E10-01 is less than 10 %, preferably less than 5 %, and Wherein the minimum distance of the centre of the indentation from the edge of the specimen or the edge of another indentation shall be at least two and a half times the diameter of the indentation and the maximum distance shall be no more than 4 times the diameter of the indentation. A steel according to any of claims 1-4, Wherein the mean impact energy measured in the LT direction of 6 samples using a standard Charpy-V test in accordance With SS-EN ISO148-1/ASTM E23 is at least 15 J, Wherein the cooling time in the temperature interval of 800 °C- 500 °C (t8/5) is 1000 s.