Abstract: A carburizing steel having the following chemical composition:C: 0.1 to 0.25%,Si: 0.2 to 0.4%,Mn: 0.3 to 0.9%,P: 0.02% or less,S: 0.001 to 0.15%,Cr: 0.5 to 0.9%,Mo: 0.15 to 1%,Al: 0.01 to 0.1%,B: 0.0005 to 0.009%,N: less than 0.006%, andthe balance of Fe and incidental impurities, wherein % is on a weight basis. Also disclosed are a method for the manufacture of the carburizing steel, parts of constant velocity universal joints for drive shafts made of the carburizing steel, as well as a method for the manufacture of such parts. The carburizing steel may further contain Ni: 0.3-4.0%, and one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each. The parts of constant velocity universal joints for drive shafts are manufactured using the carburizing steel of the present invention as a material. When they are carburized and quenched, they exhibit a surface hardness (Hv) of 650-800, core hardness (Hv) of 250-450, and carburized case depth of 0.2-1.2 mm.

Abstract: A carburizing steel having the following chemical composition:C: 0.1 to 0.25%,Si: 0.2 to 0.4%,Mn: 0.3 to 0.9%,P: 0.02% or less,S: 0.001 to 0.15%,Cr: 0.5 to 0.9%,Mo: 0.15 to 1%,Al: 0.01 to 0.1%,B: 0.0005 to 0.009%,N: less than 0.006%, andthe balance of Fe and incidental impurities, wherein % is on a weight basis. Also disclosed are a method for the manufacture of the carburizing steel, parts of constant velocity universal joints for drive shafts made of the carburizing steel, as well as a method for the manufacture of such parts. The carburizing steel may further contain Ni: 0.3-4.0%, and one or more elements selected from the group consisting of Ti, Nb, V and Zr: 0.01-0.3% for each.

Abstract: A method for producing a metallic material having an ultra-fine microstructure, the metallic material exhibiting a phase transformation of a low-temperature phase into a high-temperature phase is disclosed, the method comprising the steps of:preparing a metallic material which comprises at least a low-temperature phase;applying plastic deformation to the metallic material; andincreasing the temperature of the metallic material to a point beyond a transformation point while applying the plastic deformation to effect reverse transformation of the low-temperature phase into a high-temperature phase.

Abstract: Direct softening heat treatment of rolled wire rods comprises the steps of:providing wire rods by hot- or warm-rolling, and immediately following rolling, coiling the rolled wire rods in an annealing furnace. Apparatus therefor comprises an annealing furnace provided with an externally or internally built coiler for rolled wire rods disposed adjacent to a rolling line of said wire rods, the coiler being disposed so as to directly receive the rolled wire rods.

Abstract: Direct softening heat treatment of rolled wire rods comprises the steps:providing wire rods by hot- or warm-rolling, andimmediately following rolling, coiling the rolled wire rods in an annealing furnace. Apparatus therefor comprises an annealing furnace provided with an externally or internally built coiler for rolled wire rods disposed adjacent to a rolling line of said wire rods, the coiler being disposed so as to directly receive the rolled wire rods.

Abstract: Herein disclosed is a process for producing a steel bar or steel wire having an improved structure of spheroidal cementite. The process is characterized in that a finish rolling is conducted within a temperature range between Ar.sub.1 and Ar.sub.3 or Arcm with a reduction ratio of at least 20%.The cooling rate of the steel before the finish rolling should be controlled in the following manner:When the hardenability of the steel is not higher than that of 0.15% C plain carbon steel, it is preferable to cool the steel at a cooling rate higher than 250.degree. C./sec.When the hardenability of the steel is between those of 0.15% to 0.4% C plain carbon steel, it is preferable to cool the steel at a cooling rate higher than 10.degree. C./sec.When the hardenability of the steel is not lower than that of 0.4% C plain carbon steel, it is preferable to cool the steel at a cooling rate higher than 2.degree. C./sec.

Abstract: A process for manufacturing a high tensile steel wire, characterized by comprising the steps of pre-cooling a hot-rolled steel rod to a temperature between 750.degree.-900.degree. C. by means of a cooling apparatus provided between a group of intermediate rolling mills and a group of finishing rolling mills in a hot rolling line for steel rod, finishing rolling the thus pre-cooled steel rod, quenching the hot rolled steel rod to a temperature of 700.degree. C. or lower to provide a supercooled austenite phase, then finishing-cooling the thus quenched rod to provide martensite, and drawing the resulting steel rod with roller dies without descaling is disclosed.

Abstract: Herein disclosed are dry type continuous wire drawing process and machine which can enhance the productivity by conducting in-line a wire drawing operation including the steps of flaw detection and wire repair. The wire to be drawn is mechanically descaled and is then coated with a lubricant. The wire thus coated is drawn through a drawing die. At the coating step, the wire is first coated with lime powder and then with metallic soap. Thus, the wire is drawn under dry and continuous conditions. After the drawing operation, a flaw in surface of the wire is detected. The surface flaw is located from the running speed or distance of the wire and the detecting instant. The surface flaw located is removed. The resultant wire is wound up. The surface flaw which cannot be removed is marked. An internal defect in the drawn wire is also detected with ultrasonic waves. The internally detected portion is also marked. All of the steps thus far recited and others are conducted in-line.

Abstract: A galvanized high strength steel wire for use in stranded steel core of an aluminum conductor, steel reinforced is disclosed. The steel composition thereof consists, by weight, essentially of:C: 0.4-1.2%,Si: not more than 2.0%,Mn: not more than 2.0%,Al: not more than 0.1%,Cr: 0-5.0%,Cu: 0-1.0%,Ni: 0-1.0%,V: 0-0.5%,Nb: 0-0.2%,Ti: 0-0.2%,Zr: 0-0.2%,with the balance iron with incidental impurities of which the amounts of P, S, N and oxygen are:P: not more than 0.025%,S: not more than 0.015%,P+S: not more than 0.03%,N: not more than 0.010%,Oxygen: not more than 0.004%.

Abstract: A nonmagnetic alloy steel containing by weight 5 to 30% Mn and 0.005 to 0.5% N (nitrogen), satisfying the condition that 100/9(C%+N%)+2(Mn%+Cu%) is more than 25% and containing at least one element to improve the machinability of the steel. Since the steel contains no Ni, the steel is inexpensive and can be used for bars for reinforcing concrete and bolts for civil engineering works and buildings.