This paper presents an experimental investigation of the mechanisms of pit elimination in strip drawing and rolling of stainless steel strips. Strip drawing tests with artificial indents confirm the role of micro-plasto-hydrodynamic lubrication (MPHL) in allowing pits to be reduced in size and depth. The similarity of results for two oils, which differ in viscosity by a factor of 10, is attributed to the fact that oil is drawn out of the pits rather easily, so that the behavior tends to the unlubricated case. Similar behavior is observed for strip drawing of shot blast white hot band. For much smoother bright anneal strip, it is suggested that the presence of an oil film in the unpitted region prevents generation of pressure differences between the pits and the unpitted regions. A comparison of strip-drawn and cold-rolled stainless steel samples show that the change in pit area and Rq roughness varies with overall reduction in a remarkably similar way. The reason for such similar behavior is attributed to the absence of hydrodynamic action in preventing pit elimination, albeit for opposite reasons. The similar rate of pit evolution in both cases confirms the usefulness of the strip drawing rig as a tool to model the change of surface topography during rolling, as long as care is taken in matching the regimes of lubrication.

Issue Section:
Technical Papers
Keywords:
Asperity, Metal Rolling, Strip Drawing, Friction, Lubrication, Surface Finish, Pit, Void, Stainless Steel, stainless steel, lubrication, drawing (mechanical), cold rolling, friction
Topics:
Lubrication, Strips, Surface roughness, Stainless steel, Lubricants
1.
Fudanoki, F., 1997, “Development and Evaluation of Model for Mechanism of Formation of Surface Properties of Cold-Rolled Stainless Steel,” First International Conference on Tribology in Manufacturing Processes, Gifu, Japan, pp. 378–383.
2.
Ahmed
,
R.
, and
Sutcliffe
,
M. P. F.
,
2000
, “
Identification of Surface Features on Cold Rolled Stainless Steel Strip
,”
Wear
,
244
, pp.
60
–
70
.
3.
Rizoulie`res, B., and Montmitonnet, P., 1999, “Couches de transfer et frottement en laminage a` froid des aciers inoxydables,” Journe´es d’automne, Paris, November 1999, (in French), p. 174.
4.
Sutcliffe
,
M. P. F.
,
1988
, “
Surface Asperity Deformation in Metal Forming Processes
,”
Int. J. Mech. Sci.
,
30
, pp.
847
–
868
.
5.
Sheu, S., and Wilson, W. R. D., 1983, “Flattening of Workpiece Surface Asperities in Metalforming,” Proc. NAMRC XI, pp. 172–178.
6.
Sutcliffe
,
M. P. F.
,
1999
, “
Flattening of Random Rough Surfaces in Metal Forming
,”
ASME J. Tribol.
,
12
, pp.
433
–
440
.
7.
Wilson, W. R. D., and Walowit, J. A., 1972, “An Isothermal Hydrodynamic Lubrication Theory for Strip With Front and Back Tension,” Tribology Convention, Institute of Mechanical Engineers, London, pp. 164–172.
8.
Sutcliffe
,
M. P. F.
, and
Johnson
,
K. L.
,
1990
, “
Lubrication in Cold Strip Rolling in the ‘Mixed’ Regime
,”
Proc. Instn Mech Engrs
,
204
, pp.
249
–
261
.
9.
Sheu
,
S.
, and
Wilson
,
W. R. D.
,
1994
, “
Mixed Lubrication of Strip Rolling
,”
Tribol. Trans.
,
37
, pp.
483
–
493
.
10.
Lo
,
S. W.
,
1994
, “
A Study on the Flow Phenomena in the Mixed Lubrication Regime by Porous Medium Model
,”
ASME J. Tribol.
,
116
, pp.
640
–
647
.
11.
Kudo
,
H.
,
1965
, “
A Note on the Role of Microscopically Trapped Lubricant at the Tool-Work Interface
,”
Int. J. Mech. Sci.
,
7
, pp.
383
–
388
.
12.
Mizuno
,
T.
, and
Okamoto
,
M.
,
1982
, “
Effects of Lubricant Viscosity at Pressure and Sliding Velocity on Lubricating Conditions in the Compression Friction Test on Sheet Metals
,”
J. Lubr. Technol.
,
104
, pp.
53
–
59
.
13.
Kudo, H., and Azushima, A., 1987, “Interaction of Surface Microstructure and Lubricant in Metal Forming Tribology,” Proc. 2nd Int. Conf. on Adv. Tech. of Plasticity, Stuttgart, pp. 373.
14.
Kihara
,
J.
,
Kataoka
,
S.
, and
Aizawat
,
T.
,
1992
, “
Quantitative Evaluation of Micro-Pool Lubrication Mechanism
,”
J. Jpn. Soc. Technol. Plasticity
,
33–376
, pp.
556
–
561
.
15.
Wang, Z., Dohda, K., Yokoi, N., and Haruyama, Y., 1997, “Outflow Behavior of Lubricant in Micro Pits in Metal Forming,” First International Conference on Tribology in Manufacturing Processes, Gifu, Japan, pp. 77–82.
16.
Lo, S., and Wilson, W. R. D., 1997, “A Theoretical Model of Micro-Pool Lubrication in Metal Forming,” First International Conference on Tribology in Manufacturing Processes, Gifu, Japan, pp. 83–90.
17.
Sheu, S., Hector, L. G., and Karabin, M. E., 1999, “Two-Scale Surface Topography Design Scheme for Friction and Wear Control in Forging: Theory and Experiment,” The Integration of Material, Process and Product Design, Zabaras, et al., eds., AA Balkema, Rotterdam, pp. 157–166.
18.
Lancaster
,
P. R.
, and
Rowe
,
G. W.
,
1958
, “
A Comparison of Boundary Lubricants Under Light and Heavy Loads
,”
Wear
,
2
, pp.
428
–
437
.
19.
Thomson, P. F., and Hoggart, J. S., 1967, “The Origin of Some Surface Defects on Rolled and Drawn Products,” 20th Annual Conference, Adelaide, pp. 189–198.
20.
Evans
,
C. R.
, and
Johnson
,
K. L.
,
1986
, “
The Rheological Properties of Elastohydrodynamic Lubricants
,”
Proc. Instn Mech Engrs
,
200C
, pp.
303
–
312
.
21.
Sutcliffe
,
M. P. F.
, ,
1991
, “
Measurements of the Rheological Properties of a Kerosene Metal-Rolling Lubricant
,”
Proc. Instn Mech Engrs
,
205B
, pp.
215
–
219
.
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