Abstract: A method for manufacturing a crankshaft for an internal combustion engine with a plurality of journals having a hardened case with a first microstructure. The crankshaft is comprised of a steel comprising between about 0.3 wt % and 0.77 wt % Carbon. The first microstructure of the hardened case of the journals comprises between about 15% and 30% ferrite and a balance of martensite and the resultant subsurface residual stress between 310 MPa and 620 MPa.

Abstract: The invention relates to a furnace system and a method for the controlled heat treatment of sheet metal components in individual component zones. The invention proposes a furnace system that is suitable for partly heating components made of steel sheet to a temperature above the AC3 temperature. The furnace system has a production furnace for heating the steel sheet parts to a temperature that is close to but below the AC3 temperature, said furnace system further having a profiling furnace with at least one level. The at least one level has an upper and a lower part and a product-specific intermediate flange that is introduced into a corresponding receiving area. The product-specific intermediate flange is designed to impose a specified temperature profile on the component with temperatures over AC3 for regions to be hardened and below AC3 for softer regions. Furthermore, the invention relates to a corresponding method for partly heating steel sheet parts to a temperature above the AC3 temperature.

Abstract: The invention relates to a furnace system and a method for the controlled heat treatment of sheet metal components in individual component zones. The invention proposes a furnace system that is suitable for partly heating components made of steel sheet to a temperature above the AC3 temperature. The furnace system has a production furnace for heating the steel sheet parts to a temperature that is close to but below the AC3 temperature, said furnace system further having a profiling furnace with at least one level. The at least one level has an upper and a lower part and a product-specific intermediate flange that is introduced into a corresponding receiving area. The product-specific intermediate flange is designed to impose a specified temperature profile on the component with temperatures over AC3 for regions to be hardened and below AC3 for softer regions. Furthermore, the invention relates to a corresponding method for partly heating steel sheet parts to a temperature above the AC3 temperature.

Abstract: The present invention provides an Fe—Cr—Al-based alloy for catalyst carriers and a foil thereof having a thickness of 40 &mgr;m or less, the alloy and the foil improved in the oxidation resistance at high temperatures and having excellent deformation resistance. Specifically, the present invention provides an Fe—Cr—Al-based alloy foil and a manufacturing method thereof, comprising 16.0 to 25.0 mass % of Cr, 1 to 8 mass % of Al, La, Zr, and the balance being Fe and incidental impurities. The contents by mass % of La and Zr meet the following ranges when the foil thickness thereof is t &mgr;m: 1.4/t≦La≦6.0/t  (1) 0.6/t≦Zr≦4.0/t  (2) The Fe—Cr—Al-based alloy foil may further comprises Hf and the balance being Fe and incidental impurities, wherein the contents by mass % of La, Zr, and Hf meet the following ranges: 1.4/t≦La≦6.0/t  (1) 0.4/t≦Zr≦2.0/t  (3) 0.5/t≦Hf≦2.0/t  (4).

Abstract: A carbon steel screw has one or more portions which have been selectively hardened by selective heat treatment and quenching. In one embodiment, an upper portion of the screw head is selectively hardened to prevent or reduce damage when torque is applied using a driving tool. In another embodiment, the screw tip is selectively hardened for more effective penetration into a substrate. Preferably, the selectively heated portions are selectively quenched to reduce or avoid distortion.

Abstract: A selectively hardened nail includes a nail head, an elongated shank, and a tip. A portion of the nail shank is made harder than the remainder by selectively heat treating that portion, and cooling it. The nail has controlled bending properties. The selectively hardened portion does not significantly bend when the nail is fired at a surface using a power driving tool, or during use of the nailed object.

Abstract: An apparatus (10) for heat treat hardening multiple wear surfaces (24,26,28) of a metal workpart (14). Flame burners (38) and associated trailing quenches (36) travel along a linear and vertical path (13) across the workpart (14) to flame harden the wear surfaces (24,26,28) thereon. The workpart (14) is mounted on support studs (60) extending from a turntable (52), and clamping arms (66) securely engage the workpart (14) with the support studs (60). The turntable (52) rotates the workpart (14) relative to the travel path (13) of the flame burners (38) to move flame hardened surfaces (24,26,28) out of the travel path (13) and move unhardened surfaces (24,26,28) into the travel path (13) for flame hardening by the flame burners (38).

Abstract: A method for stress-relieving a flame-hardened component by vibrating the workpiece as it is being flame-hardened, and then vibrating the workpiece after it has been flame-hardened, measuring the workpiece to detect warpage, straightening the workpiece to remove the warpage, and then vibrating the workpiece to remove any stresses created by the straightening step.

Abstract: Remelting/hardening treatment is carried out for a work by a remelting/hardening treatment apparatus including a torch for heating the work. First, the work is firmly placed in position in the remelting/hardening treatment apparatus and a temperature of the work is then measured by a temperature detector. When the measured temperature is lower than a lower limit temperature of a predetermined or particular temperature range, a level of output from the torch is lowered and a part of the work other than a part thereof to be treated is then preheated by the torch. Thereafter, the part of the work to be treated is subjected to remelting and hardening with the aid of the torch. Consequently, production of unacceptable works can be prevented reliably, since remelting/hardening treatment is not carried out at all while the measured temperature is lower than the predetermined or particular temperature range.