Abstract:
A cobalt-free steel alloy comprising: (a) from 2 to 3 wt.% carbon, (b) from 4 to 6 wt.% chromium, (c) from 0.1 to 0.5 wt.% manganese, (d) from 0.1 to 0.9 wt.% silicon, (e) from 9 to 11 wt.% molybdenum, (f) from 6 to 8 wt.% vanadium, (g) optionally one or more of the following elements, from 0 to 0.3 wt.% copper, from 0 to 0.2 wt.% nickel, from 0 to 0.1 wt.% aluminium, from 0 to 0.05 wt.% phosphorus, from 0 to 0.05 wt.% sulphur, from 0 to 0.1 wt.% titanium, from 0 to 0.1 wt.% niobium, from 0 to 0.1 wt.% tantalum, from 0 to 0.1 wt.% boron, from 0 to 0.1 wt.% nitrogen, from 0 to 0.1 wt.% oxygen, from 0 to 0.1 wt.% calcium, from 0 to 0.1 wt.% tungsten, (h) the balance iron, together with unavoidable impurities.
Abstract:
A bearing component formed from a steel composition comprising carbon, silicon, manganese, chromium, cobalt, vanadium, optionally one or more of the following elements from sulphur, phosphorous, molybdenum, aluminium, arsenic, tin, antimony, and the balance iron, together with unavoidable impurities.
Abstract:
A casting of a white cast iron alloy is disclosed. The casting comprises the following alloy composition, in weight%: chromium: 12 - 25%; carbon: 1.5 - 6%; manganese: 2 - 7%; silicon: up to 1.5%; molybdenum: up to 2; nickel: up to 4%; microalloying elements selected from the group consisting of titanium, zirconium, niobium, boron, vanadium, and tungsten: up to 2% of each of one or more of the elements; and iron: balance. The microstructure of the casting comprises 15 - 60 vol% eutectic carbides and primary carbides dispersed in a ferrous matrix that comprises martensite and is at least substantially free of pearlite.
Abstract:
The invention relates to foundry practice and metallurgy, in particular to inoculated cast iron technology and can be used for producing various casts. The inventive method consists in: melting batch in a melting facility, a preliminary inoculation of the melt by means of treating thereof with an addition alloy which contains rare-earth metal, silicium and aluminium and subsequent inoculation with the aid of the same addition alloy that was used for the preliminary inoculation. The preliminary inoculation can be performed in a bull ladle and the following-in a casting ladle. The inventive method prevents the overmodification effect and makes it possible to obtain a perlite or ferrite-perlite matrix and a favourable form of graphite in a cast state.
Abstract:
A material of outer layer of the roll for rolling containing the following elements at respective ratio: C: 1.5-3.5 %; Si: 1.5 % or under; Mn: 1.2 % or under; Cr: 5.5-12.0 %; Mo: 2.0-8.0 %; V; 3.0-10.0 %; and Nb: 0.6-7.0 %, on condition that the following formulas: V + 1.8 Nb
Abstract:
A bimetallic composite working cylinder has an external shell made of an alloy containing iron, carbon, vanadium, chromium and molybdenum. The range of composition of the alloy represented on a carbon-vanadium curve is delimited by a quadrilateral whose sides are: a) the constant ordinate line V=3 wt.%; b) the constant abscissa line C=3wt.%; c) the peritectic line separating the delta et gamma phase regions; and d) a straight line which determines the maximum permissible vanadium content passing through two points with co-ordinates C=1.8 %, V=6% and C=3%, V=4.5%, respectively. The core of the cylinder is made of nodular graphite iron.
Abstract:
Hitherto metal pieces made of alloy cast iron Fe/Cr and exposed to wear, of which the basic mass had a martensitic character, contained, without any exception, secondary carbide deposits; this was due to the fact that these pieces, once cast, were first cooled to room temperature and, only after, submitted to high temperature treatment for the hardening. On the other hand, the metal pieces intended for exposure to wear and obtained according to the invention are substantially free of secondary carbide deposits; this is achieved as follows: the unmoulding of the moulded cores is done immediately after solidification and without any cooling under the perlite point AC u ; then, in order to destabilize the austenite, it is kept during five hours at least at a temperature above the perlite point AC u; after, the temperature is gradually lowered until it reaches room temperature, while avoiding, nevertheless, the formation of perlite and bainite. There is substantially no elimination of secondary carbides which cause deterioration of the physical characteristics of the pieces in question. The pieces obtained according to the invention are of improved and more uniform quality and have a higher resistance to deformation, while having the same resistance to wear.