| CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES |
|
|
|
|
Spall Strength of Resistance Spot Weld for QP Steel |
| Chun-Lei Fan1,2, Bo-Han Ma1, Da-Nian Chen1**, Huan-Ran Wang1, Dong-Fang Ma1 |
1Mechanics and Material Science Research Center, Ningbo University, Ningbo 315211
2Jiaxing Nanyang Polytechnic Institute, Jiaxing 314003
|
|
| Cite this article: |
|
Chun-Lei Fan, Bo-Han Ma, Da-Nian Chen et al 2016 Chin. Phys. Lett. 33 036201 |
|
|
|
|
Abstract The spall tests under the plane tensile pulses for resistance spot weld (RSW) of QP980 steel are performed by using a gun system. The velocity histories of free surfaces of the RSW are measured with the laser velocity interferometer system for any reflector. The recovered specimens are investigated with an Olympus GX71 metallographic microscope and a scanning electron microscope (SEM). The measured velocity histories are explained and used to evaluate the tension stresses in the RSW applying the characteristic theory and the assumption of Gathers. The spall strength (1977–2784 MPa) of the RSW for QP980 steel is determined based on the measured and simulated velocity histories. The spall mechanism of the RSW is brittle fracture in view of the SEM investigation of the recovered specimen. The micrographs of the as-received QP980 steel, the initial and recovered RSW of this steel for the spall test are compared to reveal the microstructure evolution during the welding and spall process. It is indicated that during the welding thermal cycle, the local martensitic phase transformation is dependent on the location within the fusion zone and the heat affected zone. It is presented that the transformation at high strain rate may be cancelled by other phenomenon while the evolution of weld defects is obvious during the spall process. It may be the stress triaxiality and strain rate effect of the RSW strength or the dynamic load-carrying capacity of the RSW structure that the spall strength of the RSW for QP980 steel is much higher than the uniaxial compression yield strength (1200 MPa) of the martensite phase in QP980 steel. Due to the weld defects in the center of the RSW, the spall strength of the RSW should be less than the conventional spall strength or the dynamic load-carrying capacity of condensed structure.
|
|
|
Received: 22 October 2015
Published: 31 March 2016
|
|
| PACS: |
62.50.Ef
|
(Shock wave effects in solids and liquids)
|
| |
62.50.-p
|
(High-pressure effects in solids and liquids)
|
| |
62.20.-x
|
(Mechanical properties of solids)
|
| |
62.30.+d
|
(Mechanical and elastic waves; vibrations)
|
|
|
|
|
|
| [1] | Wang L and Speer J G 2013 Metallogr. Microstruct. Anal. 2 268 | | [2] | Lin S H, Pan J, Wu S and Tyan T 2004 Exp. Mech. 44 147 | | [3] | Song J H, Ha J W, Huh H, Lim J H and Park S H 2008 Int. J. Mod. Phys. B 22 5527 | | [4] | Langrand B and Markiewicz E 2010 Int. J. Impact Eng. 37 792 | | [5] | Sun X and Khaleel M A 2007 Int. J. Impact Eng. 34 1668 | | [6] | Marya M, Wang K, Hector L G and Gayden X 2006 J. Manuf. Sci. Eng. 128 287 | | [7] | Porcaro R, Hanssen A G, Aalberg A and Langseth M 2004 Int. J. Crashworthiness 9 141 | | [8] | Xu Z and Li Y 2009 Mech. Mater. 41 121 | | [9] | Yang X, Jr L G and Wang J 2014 Exp. Mech. 54 775 | | [10] | Khan M I, Kuntz M L and Zhou Y 2008 Sci. Technol. Weld. Joining 13 294 | | [11] | Ma B H, Fan C L, Chen D N, Wang H R and Zhou F H 2014 J. Appl. Phys. 116 053503 | | [12] | Gathers G R 1990 J. Appl. Phys. 67 4090 | | [13] | Choi K S, Liu W N, Sun X and Khaleel M A 2009 Acta Mater. 57 2592 | | [14] | Delannay L, Jacques P and Pardoen T 2008 Int. J. Solids Struct. 45 1825 | | [15] | Al-Abbasi F M and Nemes J A 2003 Int. J. Mech. Sci. 45 1449 | | [16] | Srivastava A, Ghassemi-Armaki H, Sung H, Chen P, Kumar S and Bower A F 2015 J. Mech. Phys. Solids 78 46 | | [17] | Baltazar Hernandez V H, Panda S K, Kuntz M L and Zhou Y 2010 Mater. Lett. 64 207 | | [18] | Grady D E 1988 J. Mech. Phys. Solids 36 353 | | [19] | Dekel E, Eliezer S, Henis Z, Moshe E, Ludmirsky A and Goldberg I B 1998 J. Appl. Phys. 84 4851 | | [20] | Murray N H, Bourne N K, Rosenberg Z and Field J E 1998 J. Appl. Phys. 84 734 | | [21] | Diaz-Rubio F G, Perez J R and Galvez V S 2002 Int. J. Impact Eng. 27 161 | | [22] | Morozov N and Petrov Y 2000 Dynamic of fracture (Springer) | | [23] | Ou Z C, Duan Z P and Huang F L 2010 Int. J. Impact Eng. 37 942 | | [24] | Cotsovos D M and Pavlovic M N 2008 Int. J. Impact Eng. 35 319 | | [25] | Yu Y, He H L, Wang W Q and Lu T C 2014 Acta Phys. Sin. 63 246102 (in Chinese) |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
