Abstract: A method is proposed for the production of high-strength low-expansion cast iron enabled to acquire improved strength, hardness, and cutting workability while retaining the property of low expansion intact. The product is a low-expansion cast iron having a high nickel content and exhibiting a coefficient of thermal expansion of not more than 8.times.10.sup.-6 /.degree. C. at temperatures in the range of from room temperature to 100.degree. C. By causing a carbide to be finely precipitated in an area ratio in the range of from 0.3% to 20% in the metal structure of the cast iron and lowering the C content in the cast iron, there is produced a high-strength low-expansion cast iron. The deposition of the carbide mentioned above is accomplished by incorporating in the material for cast iron at least one element selected from the group consisting of the transition metal elements of IVa, Va, and VIa Groups in the Periodic Table of the Elements.

Abstract: This invention provides a metal-bonded tool in which iron-base alloy powder and abrasive grains are bonded to each other. The quantity of the carbon or graphite in the bond being between 2.5 wt % or more and 4.5 wt % or less of the bond, and the diameter of the precipitated carbon or graphite being 5 .mu.m or less in the bond.

Abstract: Disclosed is a process for producing a magnetic core, comprising the first step of bringing magnetic powder of a metal into contact with a polymer dispersion, followed by drying, to form an insulating layer on the surface of the magnetic powder and the second step of compression molding the magnetic powder. Also, disclosed is a magnetic core produced by the above process.A magnetic core according to this invention has, since good insulation between magnetic powder particles can be ensured with a small amount of an insulating material, high magnetic flux density, small core loss and excellent frequency characteristics of magnetic permeability and is particularly suitable for use in high frequency range of some 10 KHz or higher.

Abstract: There is disclosed a wear-resistant alloy which comprises, in terms of weight ratio, 10 to 45% of chromium, 3 to 15% of niobium, 4 to 20% of molybdenum, 0.01 to 2.0% of boron, and nickel as the remainder.The wear-resistant alloy having a novel composition of the present invention is suitable for face portions of valves used in various plants such as a chemical plant and an atomic power plant, parts of jet pumps and sliding parts for various machines.

Abstract: A wear-resistant alloy for an atomic power plant which is essentially formed of 10 to 45% by weight of chromium; 1.5 to 6% by weight of at least one metal component selected from the group consisting of aluminium and titanium; 0 to 20% by weight of molybdenum; and nickel as the remainder, and atomic power plant parts prepared from the alloy having said composition.