Kobe Steel, Ltd.

Nhk Spring Co., Ltd.

Tohoku University

Mazda Motor Corporat Ion

Kabushiki Kaisha Kobe Seiko Sho

Kazuya Ikai

Takeshi Suzuki

Yoshiki Ono

Masaaki Tanaka

Akihiko Chiba

Ken Yamashita

Tohru Shiraishi

Tetsunao Ikeda

Mitsugi Fukahori

Hiroaki Matsumoto

Yasuyuki Yokota

Sang-Hak Lee

Hikaru Kinashi

Yuichiro Ono

Ryota Yamasaki

Kazuma Kumagai

An arc welding solid wire includes: a steel material; and a copper plating layer formed on a surface of the steel material, in which an amount of Cu in the steel material and the copper plating layer is 0.05 mass % to 0.30 mass % with respect to a total mass of the wire, a surface of the wire is coated with 0.05 g to 0.20 g of oil with respect to 1 kg of the wire, and on a surface of the copper plating layer, an arithmetic average roughness Rac in a circumferential direction is 0.25 μm to 1.00 μm, and an arithmetic average roughness Ral in a longitudinal direction is 0.07 μm to 0.50 μm.

Solid wire for arc welding use

A gas shielded arc welding wire contains, based on total mass of the wire in terms of mass %: C: 0.01% to 0.50%; Si: 0.01% to 1.50%; Mn: 0.10% to 2.50%; Cr: 5% to 15%; Ni: 0.05% to 1.50%; Mo: 0.1% to 2.0%; V: 0.1% to 1.0%; Nb: 0.01% to 0.20%; REM: 0.001% to 0.050%; S: 0.0010% to 0.0200%; and O: 0.025% or less (including 0%), which satisfies the following relationship: 3.0≤(Nb+10×REM)/(S+O)≤200.0.

Gas-shielded arc welding wire and gas-shielded arc welding method

A gas shielded arc welding method includes welding a steel sheet with a tensile strength of 780 MPa or more using a shielding gas containing Ar in an amount of 92 vol. % to 99.5 vol. %. In the gas shielded arc welding method, a value calculated from the following expression (1) is 0.20 or more: {&#x221a;v/(D/2)}&#xd7;10&#x2212;{(100&#x2212;C)&#xd7;I/v}&#xd7;0.1 . . . (1), where Crepresents an Ar content (vol. %) in the shielding gas, D represents an inner diameter (mm) of a nozzle from which the shielding gas is supplied, v represents a welding speed (cm/min), and I represents a welding current (A).

Gas shielded arc welding method

A wire for gas-shielded arc welding includes, based on a total mass of the wire: C: 0.01 mass % or more and 0.10 mass % or less, Si: 0.05 mass % or more and 0.55 mass % or less, Mn: 1.60 mass % or more and 2.40 mass % or less, Ti: 0.05 mass % or more and 0.25 mass % or less, Cu: 0.01 mass % or more and 0.30 mass % or less, S: 0.001 mass % or more and 0.020 mass % or less, N: 0.0045 mass % or more and 0.0150 mass % or less, Al: 0.10 mass % or less, and P: 0.025 mass % or less, with the remainder being Fe and inevitable impurities. In the wire, the following relationship is satisfied: 0.1&#x2264;[Ti]/[Si]&#x2264;3.0, where [Si] is the content of Si (mass %) and [Ti] is the content of Ti (mass %).

Wire for gas-shielded arc welding

A compression coil spring having high durability can be provided by using an inexpensive wire material. The present invention provides a compression coil spring formed by using a steel wire material, the steel wire material made of C: 0.45 to 0.85 mass %, Si: 0.15 to 2.5 mass %, Mn: 0.3 to 1.0 mass %, Fe and inevitable impurities as a remainder, and a circle-equivalent diameter of 1.5 to 9.0 mm, wherein hardness of a freely selected cross-section of the wire material is 570 to 700 HV, and at an inner diameter side of the coil spring, unloaded compressive residual stress at a depth of 0.2 mm from a surface in an approximate maximal main stress direction in a case in which compressive load is loaded on the spring is 200 MPa or more, and unloaded compressive residual stress at a depth of 0.4 mm from surface is 100 MPa or more.

Compression coil spring and method for producing same

A titanium alloy has high strength and superior workability and is preferably used for various structural materials for automobiles, etc. The titanium alloy is obtained by the following production method. An alloy having a structure of &#x3b1;' martensite phase is hot worked at conditions at which dynamic recrystallization occurs. The working is performed at a heating rate of 50 to 800&#xb0; C./second at a strain rate of 0.01 to 10/second when the temperature is 700 to 800&#xb0; C. or at a strain rate of 0.1 to 10/second when the temperature is more than 800&#xb0; C. and less than 1000&#xb0; C. so as to provide a strain of not less than 0.5. Thus, equiaxed crystals with an average grain size of less than 1000 nm are obtained.

Nanocrystal titanium alloy and production method for same

Growing community of inventors

Kanagawa, Japan

Kazuya Ikai