Welding and Joining Research Center

Futtsu, Japan

Welding and Joining Research Center

Futtsu, Japan
SEARCH FILTERS
Time filter
Source Type

Furusako S.,Welding and Joining Research Center | Murayama G.,Welding and Joining Research Center | Oikawa H.,Welding and Joining Research Center | Nose T.,Welding and Joining Research Center | And 3 more authors.
Nippon Steel Technical Report | Year: 2013

Application of high strength steel for the auto body has been increasing, because lightness is required in order to reduce CO2 emissions at the same time as the high collision safety. This paper focused on technology trend and research progress concerning welding techniques which are being used for the assembly of auto bodies. On the resistance spot welding, the following results were introduced: 1) stress analysis by FEM in case of cross tension test for joint using high strength steel sheet, 2) improvement technique of cross tension strength based upon the FEM analysis, 3) welding technique of three steel sheets with a combination of substantially different thicknesses and 4) welding tecnique of an open section component like a hydroformed one.


Uemori R.,Tube and Shape Research Laboratory | Hasegawa Y.,Tube and Shape Research Laboratory | Hara T.,Kimitsu R and D Laboratory | Inoue T.,Tube and Shape Research Laboratory | And 3 more authors.
Nippon Steel Technical Report | Year: 2012

Oil, coal and natural gas, which are fossil fuels, account for the great majority of energy resources. Therefore, it is extremely important to produce and transport them at reasonable cost. In particular, high-performance steels are indispensable for the production and transportation of crude oil and natural gas. They include the development of new steels with superior high-temperature strength, new corrosion-resistant steels for boilers that use heavy oil or biomass as their fuel, and the study of thicker heavy-section steels with greater strength and toughness which allow for an increase in the hydroelectric power generating capacity of dams. In industries such as thermal, nuclear and hydroelectric power generation, positive efforts have also been made to enhance the performance of steels. They include the development of new steels with superior high-temperature strength, new corrosion-resistant steels for boilers that use heavy oil or biomass as their fuel, and the study of thicker heavy-section steels with greater strength and toughness which allow for an increase in the hydroelectric power generating capacity of dams.


Mironov S.,Tohoku University | Sato Y.S.,Tohoku University | Kokawa H.,Tohoku University | Inoue H.,Welding and Joining Research Center | Tsuge S.,Nippon Steel & Sumitomo Metal Corporation
Acta Materialia | Year: 2011

Electron backscattering diffraction was employed to study grain structure development and texture evolution during friction stir welding (FSW) of a low stacking fault energy material, S31254 superaustenitic stainless steel. Formation of the final stir zone (SZ) microstructure was deduced to be primarily governed by discontinuous recrystallization occurring during the FSW cooling cycle. The textural pattern formed in the SZ was interpreted in the terms of {1 1 1}〈u v w〉 and {h k l}〈1 1 0〉 partial simple shear fiber textures. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


Okawa T.,Nippon Steel & Sumitomo Metal Corporation | Shimanuki H.,Tube and Shape Research Laboratory | Nose T.,Welding and Joining Research Center | Suzuki T.,Materials Characterization Research Laboratory
Nippon Steel Technical Report | Year: 2013

A fatigue life prediction system for welded structures has been developed based on crack growth analysis. In the developed system, the fatigue life can be predicted taking into account the effects of the residual stress and the load sequences by the crack opening and closure simulation. Furthermore, the effect of fatigue strength improvement techniques, such as UIT, can be accurately predicted by the developed system.


Nose T.,Welding and Joining Research Center | Okawa T.,Nippon Steel & Sumitomo Metal Corporation
Nippon Steel Technical Report | Year: 2012

Many steel structures are fabricated by welding steel materials together. When a fracture occurs in a welded steel structure, the origin is often a weld zone. The reason for this is that the weld zone is structurally susceptible to stress concentration and that there is the possibility of various defects. Nippon Steel Corporation has long engaged in the development of technology to improve the reliability of weld zones in steel structures. Among others, the company has been striving to establish and offer a total solution for fatigue fractures hoping to deliver high performance steel products which are safe and secure. Nippon Steel Corporation has long engaged in the development of technology to improve the reliability of weld zones in steel structures. Among others, the company has been striving to establish and offer a total solution for fatigue fractures hoping to deliver high performance steel products which are safe and secure.


Kodama S.,Welding and Joining Research Center | Furusako S.,Welding and Joining Research Center | Miyazaki Y.,Welding and Joining Research Center | Ishida Y.,Kimitsu R and D Laboratory | And 2 more authors.
Nippon Steel Technical Report | Year: 2013

Recent research progresses of arc welding techniques are described, focusing on the automotive chassis members or body members. As for welded joint performance, static strength and fatigue strength are improved with increasing of steel strength less than 780 MPa tensile strength. Additionally, galvanized steel sheets contribute to corrosion resistance of weld parts. Developed welding materials have made it possible to improve welding activities such as reducing spatters, gap allowance or weldability of galvanized steel sheets. In contrast, components of the steel sheet also effects on welding phenomenon, a flat bead geometry is obtained by increasing Si content of steel sheets. Low heat input welding such as CMT (Cold metal transfer) welding has begun to use for body welding and cross tension strength of advanced high tensile strength steel are improved by CMT applied arc spot welding.


Kubo Y.,Surface Treatment Research Laboratory | Hanya K.,Steel Structure R and nter | Kodama S.,Welding and Joining Research Center
Nippon Steel Technical Report | Year: 2012

The contribution to energy savings through reduced iron loss of non-oriented electrical steel sheet for motors and the development of stainless steels with good corrosion resistance and aesthetic appeal may be cited as cases in point. When steel sheet with lubricating film is used for the cartridge tank of an oil-powered fan heater, for example, since the film itself plays the same role as paint with good corrosion resistance, the prescribed corrosion resistance can be secured even if the painting process after press forming is omitted. As a base resin, a polyurethanebased resin has been adopted in view of the relationship between tensile strength and longation. The underlying concept is that the resin used for film is designed and developed based on an understanding of the properties of various base metals, plating types and resins, and that the lubricant and other functional materials are designed so as to develop various types of films with not only high lubricating performance, but also good corrosion resistance, formability, and electrical conductivity. This concept has also been applied to the development of various films for surface-treated steel sheets.


Takahashi M.,Steel Research Laboratorie | Suehiro M.,A-D Technologies | Ochi T.,Muroran R and D Laboratory | Miyazaki Y.,Welding and Joining Research Center
Nippon Steel Technical Report | Year: 2012

Steel production in Japan grew in tandem with the growth in domestic automobile production. Understandably, therefore, past development and expansion of the Japanese steel industry cannot be discussed without reference to the automotive industry of Japan. While the collision characteristics of a complete car body are ultimately evaluated through crash tests using real automobiles, to clarify the effects of individual improvement measures, it is necessary to examine the deformation behavior of the structure of the whole body prescribed parts and of the individual parts. While the crash energy absorbing property of frontal or rear collision by plastic deformation increases with increasing strength of the steel used, press formability improves with decreasing strength, and for this reason, steel sheets that are soft at the time of press forming and harden at the time of use, or those having strength highly dependent on strain rate, are desirable. However, the strain-rate dependence of steel strength decreases as the strength increases.


Sakiyama T.,Welding and Joining Research Center | Naito Y.,Welding and Joining Research Center | Miyazaki Y.,Welding and Joining Research Center | Nose T.,Welding and Joining Research Center | And 3 more authors.
Nippon Steel Technical Report | Year: 2013

Multi-material structure of auto body partially employing aluminum alloy sheets may be adopted in order to satisfy requests at the same time improving crash safety and lightweight. This paper described the dissimilar metal joining technologies required to achieve multimaterial structure. In resistance spot welding, high current & short time welding condition is conducted to avoid formation of brittle Fe-Al intermetallic compound layer at joint interface and joint strength is investigated. In mechanical joining, current application situation of SPR, Tog-L-Loc®, TOX® and FDS® methods are outlined and application examples of Blind rivet in automobile body are introduced. In addition to that, joint strengths in shear direction of SPR joints for cold rolled steel sheets and 6000 series aluminum alloy sheets are described. In adhesion bonding, it was shown that joint strength of TSS over 20 MPa is obtained by using of recent adhesive for automobile in sheet combinations of cold rolled mild steel sheets and 6000 series aluminum alloy sheets. In FSSW, effects of holding time, rotating speed and coating layer on joint strength were clarified in sheet combinations of Super Dyma® steel sheets and 6000 series aluminum alloy sheets. Also, in laser brazing, it was shown that joining of cold rolled or GA mild steel sheets and 6000 series aluminum alloy sheets are possible by using 4000 series aluminum alloy filler (A4043) with fluoride type NOCOLOK® flux. Finally, direction of development needed in the future in the field of dissimilar metal joining technologies of steel and aluminum alloy was described based on past development history.


Naito Y.,Welding and Joining Research Center | Sakiyama T.,Welding and Joining Research Center | Nose T.,Welding and Joining Research Center | Kodama S.,Welding and Joining Research Center | Miyazaki Y.,Welding and Joining Research Center
Nippon Steel Technical Report | Year: 2013

Research progress concerning laser welding and mechanical clinching which are being used for the assembly of auto bodies. On the laser welding, usage of remote welding is recently expanding, therefore, the next things were shown: 1) attenuation phenomenon of laser power, as an important point on the remote welding, caused by plume blowing out of workpiece, 2) hybrid spot welding technique applicable for the welding of three steel sheets highly differing in thickness and 3) laser welding method accompanied with filler vibration corresponding to the welding with a gap between steel sheets. Furthermore, as a non-melting joining technique, mechanical clinching was referred to and property of strength concerning one-side riveted joints were introduced.

Loading Welding and Joining Research Center collaborators
Loading Welding and Joining Research Center collaborators