An ultra-high-strength spring steel for an engine valve spring steel comprises, by weight: 0.5-0.7% of carbon (C), 1.3-2.3% of silicon (Si), 0.6-1.2% of manganese (Mn), 0.6-1.2% of chrome (Cr), 0.1-0.5% of molybdenum (Mo), 0.05-0.8% of nickel (Ni), 0.05-0.5% of vanadium (V), 0.05-0.5% of niobium (Nb), 0.05-0.3% of titanium (Ti), 0.001-0.01% of boron (B), 0.01-0.52% of tungsten (W), 0.3% or less (0% exclusive) of copper (Cu), 0.3% or less (0% exclusive) of aluminum (Al), 0.03% or less (0% exclusive) of nitrogen (N), 0.003% or less (0% exclusive) of oxygen (O), and a remainder of Fe and other inevitable impurities, based on 100% by weight of the ultra-high-strength spring steel.

A brake disk includes a basic material formed of gray cast iron, a decarburized layer formed on the basic material and formed via decarburizing, and a nitride compound layer formed on the decarburized layer and formed via nitriding of a nitride. A method of manufacturing a brake disk includes preparing a disk formed of gray cast iron, performing heat treatment of the disk to form a pre-decarburized layer and a base layer of gray cast iron over which the pre-decarburized layer is formed, and nitriding a portion of the pre-decarburized layer to form a nitride compound layer including a nitride and a decarburized layer over which the nitride compound layer is formed.

A brake disk includes a basic material formed of gray cast iron, a decarburized layer formed on the basic material and formed via decarburizing, and a nitride compound layer formed on the decarburized layer and formed via nitriding of a nitride. A method of manufacturing a brake disk includes preparing a disk formed of gray cast iron, performing heat treatment of the disk to form a pre-decarburized layer and a base layer of gray cast iron over which the pre-decarburized layer is formed, and nitriding a portion of the pre-decarburized layer to form a nitride compound layer including a nitride and a decarburized layer over which the nitride compound layer is formed.

Provided is a black heart malleable cast iron and a method for manufacturing the same which can significantly shorten the time required for graphitization, as compared with the prior art. The black heart malleable cast iron includes a matrix of ferrite and lump graphite included in the matrix, and includes at least one selected from the group consisting of (i) 0.0050% by mass or more and 0.15% by mass or less of bismuth and 0.020% by mass or more of manganese, and (ii) 0.0050% by mass or more and 1.0% by mass or less of aluminum and 0.0050% by mass or more of nitrogen. In addition, the grain size of the matrix is 8.0 or more and 10.0 or less in terms of grain size number, numerically determined by comparison between a metallographic photograph of the matrix and a standard grain size chart.

The present invention refers to a vermicular cast iron alloy specially designed for internal combustion engine blocks and heads having special requirements of mechanical strength and fatigue strength. Vermicular iron alloy with high mechanical strength and high fatigue strength for the production of internal combustion engines blocks and heads characterized by having a microstructure of pearlitic matrix and predominantly vermicular graphite (>70%) and presence of graphite nodules in up to 30%, wherein its graphite microstructure is described by the Microstructure Factor (FM), as defined below, with Microstructure Factor values higher than 0.94.

The present invention refers to a vermicular cast iron alloy specially designed for internal combustion engine blocks and heads having special requirements of mechanical strength and fatigue strength. Vermicular iron alloy with high mechanical strength and high fatigue strength for the production of internal combustion engines blocks and heads characterized by having a microstructure of pearlitic matrix and predominantly vermicular graphite (>70%) and presence of graphite nodules in up to 30%, wherein its graphite microstructure is described by the Microstructure Factor (FM), as defined below, with Microstructure Factor values higher than 0.94.

A friction brake body for a friction brake of a motor vehicle, in particular a brake disk, includes a base body made in particular from gray cast iron and having at least one wear resistant layer formed on a friction contact surface of the base body. The wear resistant layer is made from ferritic-austenitic steel and includes an incorporated hard material particle, in particular finely distributed hard material particle.

A cast for producing end plates for a pump assembly, the cast comprising a base portion and a pair of projections, the pair of projections providing material to machine bearing assembly housings for accommodating drive and idler shafts in the pump assembly. Also provided is an inner plate bushing for an end plate in a pump assembly, the inner plate bushing comprising a collar extending from a flange, the collar to be inserted into a mounting recess in the end plate with the flange seating flush with a surface of the end plate, the surface area of an end of the collar being larger than an inner surface of the flange.

A cast for producing end plates for a pump assembly, the cast comprising a base portion and a pair of projections, the pair of projections providing material to machine bearing assembly housings for accommodating drive and idler shafts in the pump assembly. Also provided is an inner plate bushing for an end plate in a pump assembly, the inner plate bushing comprising a collar extending from a flange, the collar to be inserted into a mounting recess in the end plate with the flange seating flush with a surface of the end plate, the surface area of an end of the collar being larger than an inner surface of the flange.

A robot includes a first member, a second member provided to be capable of turning with respect to the first member, and a gear device configured to transmit a driving force from one side to the other side of the first member and the second member. The gear device includes internal teeth and external teeth provided halfway in a transmission path of the driving force and configured to mesh with each other and lubricant disposed between the internal teeth and the external teeth. An average grain size of a constituent material of the external teeth is smaller than an average grain size of a constituent material of the internal teeth.