A method of manufacturing an outer joint member of a constant velocity universal joint includes forming cup and shaft members of medium carbon steel, forging the cup member to have integrally formed cylindrical and bottom portions, and machining a joining end surface on an outer surface of the bottom portion after the forging. The method also includes preparing the shaft member to have a joining end surface to be joined to the bottom portion of the cup member, which is formed by machining, bringing the joining end surfaces of the cup and shaft members into abutment against each other and welding the cup and shaft members by radiating a beam from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member.

A method of manufacturing an outer joint member of a constant velocity universal joint includes forming cup and shaft members of medium carbon steel, forging the cup member to have integrally formed cylindrical and bottom portions, and machining a joining end surface on an outer surface of the bottom portion after the forging. The method also includes preparing the shaft member to have a joining end surface to be joined to the bottom portion of the cup member, which is formed by machining, bringing the joining end surfaces of the cup and shaft members into abutment against each other and welding the cup and shaft members by radiating a beam from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member.

An apparatus for backward flow forming a material may comprise a mandrel having a headstock at a proximate end of the mandrel, the mandrel configured to rotate about an axis, a plurality of rollers disposed radially outward of the mandrel configured to exert force on the material to form a work piece at a plastic deformation zone, wherein the work piece flows from the plastic deformation zone between the plurality of rollers and the mandrel toward a distal end of the mandrel, and a catcher, coaxial to the mandrel, and removably coupled to the work piece at a traveling end of the work piece.

Provided is a method for fabricating a stepped forged material that can realize a uniform microscopic structure in both the large diameter flange portion and the small diameter shaft portion. This method for fabricating a stepped forged material comprises the following steps: a step for obtaining a primary forged material in which an austenite stainless steel billet is heated to 1000-1080 C., and, without any further heating, the material is forged by means of reciprocal forging into a round rod having along the entire length thereof a forging ratio of 1.5 or greater; a step for obtaining a secondary forged material, that forms the large diameter flange portion and the small diameter shaft portion, in which without reheating, the small diameter shaft portion is formed by means of reciprocal forging at a temperature where the surface temperature of the primary forged material never falls more than 200 C. lower than the abovementioned material heating temperature and the forging is completed before the surface temperature of the final forged portion falls more than 300 C. lower than the abovementioned heating temperature; and a step for performing a solution heat treatment in which the secondary forged material is heated to 1040-1100 C. for 30 minutes or longer.

Provided is a method for fabricating a stepped forged material that can realize a uniform microscopic structure in both the large diameter flange portion and the small diameter shaft portion. This method for fabricating a stepped forged material comprises the following steps: a step for obtaining a primary forged material in which an austenite stainless steel billet is heated to 1000-1080 C., and, without any further heating, the material is forged by means of reciprocal forging into a round rod having along the entire length thereof a forging ratio of 1.5 or greater; a step for obtaining a secondary forged material, that forms the large diameter flange portion and the small diameter shaft portion, in which without reheating, the small diameter shaft portion is formed by means of reciprocal forging at a temperature where the surface temperature of the primary forged material never falls more than 200 C. lower than the abovementioned material heating temperature and the forging is completed before the surface temperature of the final forged portion falls more than 300 C. lower than the abovementioned heating temperature; and a step for performing a solution heat treatment in which the secondary forged material is heated to 1040-1100 C. for 30 minutes or longer.

Steel for which the composition is, in weight percentages: 0.35%C0.50%; 0.30%Mn1.50%; trace amounts Cr1.50%; 0.05%Mo0.50%; 0.15Si1.20%; trace amounts Ni1.0%; trace amounts Cu1.0%; trace amounts V0.35%; trace amounts Al0.10%; trace amounts B0.005%; trace amounts Ti0.10%; trace amounts Nb0.10%; trace amounts S0.15%; trace amounts Ca0.010%; trace amounts Te0.030%; trace amounts Se0.050%; trace amounts Bi0.050%; trace amounts Pb0.100%; trace amounts N0.020%; the remainder being iron and impurities resulting from the elaboration, and the C, Mn and Cr contents being such that 830-270 C %-90 Mn %-70 Cr %)620.

An embodiment includes a method, comprising: applying an overlay material to a portion of a rotatable shaft; directing a pulse of laser energy to contact the overlay material to produce a shock wave; and re-positioning one or more of the portion of the rotatable shaft and the pulse of laser energy to contact the overlay material at different positions to create a laser peened surface on the portion of the rotatable shaft; the pulse of laser energy comprising a pulse sufficient to create the laser peened surface having residual compressive stress to a depth exceeding about 3 mm. Other aspects are described and claimed.

in a heat treatment method for a tubular shaft for a drive shaft having a ball spline structure for a plunging and an undercut region with a reduced diameter, a carburizing-austempering is performed such that a deep portion hardness of the undercut region is a value between HRC 35 to HRC 50.

in a heat treatment method for a tubular shaft for a drive shaft having a ball spline structure for a plunging and an undercut region with a reduced diameter, a carburizing-austempering is performed such that a deep portion hardness of the undercut region is a value between HRC 35 to HRC 50.

It is provided a mechanical structural part and a method of manufacturing the same. The mechanical structural part comprises a chemical composition containing C: 0.45% to 0.51%, Si: 0.15% to 0.35%, Mn: 0.60% to 0.90%, P: 0.030% or less, S: 0.025% or less, Al: 0.040% to 0.059%, Cr: 0.10% to 0.50%, and N: 0.0060% to 0.0100%, with the balance being Fe and inevitable impurities, and a hardened layer by induction hardening and tempering treatment, wherein an area ratio of crystal grains each having a prior austenite grain size of 80 m or less in the hardened layer is 80% or more, and a number ratio of grains each having a grain size twice or more than a mode of grain size in the hardened layer is 5% or less.