Research Papers

Effects of Workshop Fabrication Processes on the Deformation Capacity of S960 Ultra-high Strength Steel

[+] Author and Article Information
M. Amraei

School of Energy Systems,
Lappeenranta University of Technology,
P.O. Box 20,
Lappeenranta 53851, Finland
e-mail: mohsen.amraei@lut.fi

M. Dabiri, T. Björk, T. Skriko

School of Energy Systems,
Lappeenranta University of Technology,
P.O. Box 20,
Lappeenranta 53851, Finland

1Corresponding author.

Manuscript received February 23, 2016; final manuscript received June 10, 2016; published online July 25, 2016. Assoc. Editor: Gracious Ngaile.

J. Manuf. Sci. Eng 138(12), 121007 (Jul 25, 2016) (13 pages) Paper No: MANU-16-1123; doi: 10.1115/1.4033930 History: Received February 23, 2016; Revised June 10, 2016

Deformation of a direct quenched type of ultra-high strength steel (UHSS) with low-carbon content is studied in this work. Although this material, as manufactured, combines high strength and good ductility, it is highly sensitive to the workshop fabrication processes used. The presence of stress concentration due to structural discontinuity or notch effects can accentuate the effect of fabrication processes on the deformation capacity of the material. To evaluate the influence of fabrication methods on deformation capacity, a series of tensile tests are done on both pure base material (BM) and after the steel has been subjected to heat input (HI) or cold forming (CF). To study the effect of HI due to welding or other heat-based workshop fabrication processes, the surface of the material was dressed by laser beam at controlled speed and laser intensity. CF effects were studied by bending the specimens to a predetermined angle prior to subjecting the steel to tensile testing. Experimental results were compared with numerical simulation using ls-dyna simulation software. The generated results show acceptable agreement between experimental and numerical simulation outcomes.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 1

SEM of the BM, LB, martensite (M), and autotempered martensite (AM) [26]

Grahic Jump Location
Fig. 2

5 MN test machine with installed ARAMIS used for the experimental tests

Grahic Jump Location
Fig. 3

(a) Schematic of test specimen with hole-diameter of 40 mm. (b) Measured engineering stress–strain curve of BM without hole.

Grahic Jump Location
Fig. 4

BM under tensile loading at the fracture point. From left to right hole-size increases: (a) test specimens and (b) ARAMIS plastic deformation contour.

Grahic Jump Location
Fig. 5

Measured engineering stress–strain and force–displacement curves in gauge length of 80 mm for BM

Grahic Jump Location
Fig. 6

(a) Distribution of the heat and the considered areas for hardness measurement and (b) microhardness of the material at different zones

Grahic Jump Location
Fig. 7

Macroscopic view toward thickness and different zones at the material after experiencing heat

Grahic Jump Location
Fig. 8

Microstructure of the material experiencing heat from FZ to BM: (a) FZ, (b) CGHAZ, (c) FGHAZ, (d) ICHAZ, (e) SCHAZ, and (f) transient area

Grahic Jump Location
Fig. 9

Comparison of force–displacement curves after material experienced heat and BM

Grahic Jump Location
Fig. 10

HI results from ARAMIS for the specimen without hole: (a) plastic strain distribution at the failure point and (b) effective stress–strain curves till 16% strain of HAZ

Grahic Jump Location
Fig. 11

Distribution of strain on HI specimens right before fracture point (cracks are pointed with array). Sample with hole of (a) 8 mm, (b) 24 mm, and (c) 40 mm.

Grahic Jump Location
Fig. 12

(a) Three-point bending procedure to study the effect of CF on the behavior of the material and (b) CF specimen

Grahic Jump Location
Fig. 13

Load–displacement curves after CF effect and the BM

Grahic Jump Location
Fig. 14

The specimens right before the fracture point including ARAMIS results

Grahic Jump Location
Fig. 15

Effective stress–plastic strain curve used for the BM

Grahic Jump Location
Fig. 16

Comparison of test and FE load–displacement curves for BM

Grahic Jump Location
Fig. 17

Macroscopic fracture of the BM from both experimental and FE, hole-diameter (mm) from left to right: 40, 24, 8, and 0

Grahic Jump Location
Fig. 18

Macroscopic fracture of the material after experiencing HI from both experimental and FE

Grahic Jump Location
Fig. 19

Comparison of load–displacement curves from experimental tests and FEA after (a) HI- and (b) CF- process

Grahic Jump Location
Fig. 20

Fracture surfaces (hole-diameter of 0, 8, 24, and 40 mm from left to right): the first row is for BM and the lower one is after HI

Grahic Jump Location
Fig. 21

SEM view of the fracture surface of the material after experiencing heat with hole of 40 mm

Grahic Jump Location
Fig. 22

Aramis versus FE results after experiencing heat without hole

Grahic Jump Location
Fig. 23

Macroscopic fracture of BM and after CF




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In