Intermediate Frequency Spot Welding Performance Investigation of Precision Ultra-high Strength Quenching Steel Plate

• Published in: ISIJ International Vol. 49; no. 9; pp. 1378 - 1383
• Main Authors: Gu, Z. W., Zhang, Z. L., Han, L. J., Xu, H.
• Format: Journal Article
• Language: English
• Published: Tokyo The Iron and Steel Institute of Japan 01-01-2009; Iron and Steel Institute of Japan
• Subjects: Applied sciences; EN 10 292 TL4225; Exact sciences and technology; IF spot welding; Joining, thermal cutting: metallurgical aspects; Metals. Metallurgy; precision ultra-high strength steel sheet; Welding; Heat treatment; IF spot welding; Sheet metal; High strength steel; Resistance spot welding; Spot welding; EN 10 292 TL4225; precision ultra-high strength steel sheet; Strength; Quenching
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.49.1378

In recent years the precision ultra-high strength quenching steel plates (PUHSQS) have been widely used in the automobile production to reduce weight and improve passive safety. This paper investigates the spot welding performance of PUHSQS EN 1029TL4225, a kind of advanced high strength steel, whose tension strength can attain 1500 MPa after being quenched. Using the intermediate frequency (IF) spot welding process, two kinds of welded joints are made: the joint of two PUHSQS plates and the joint between PUHSQS EN 10292TL4225 and the micro-alloy steel H340 LAD. The mechanical performances of welded joints, such as the tension strength, the hardness distribution, are tested. Besides, the macrostructure and microstructure are also analyzed. From the results, we can see that both of two kinds of welded joints have perfect properties and internal quality, and also the mechanical performances meet the actual production requirement completely. So we conclude that the steel EN 10 292 TL4225 has good spot welding performance.