On the Analysis of Die Wear in Wire Drawing Process

Tribology Transactions

ISSN: 1040-2004 (Print) 1547-397X (Online) Journal homepage: http://www.tandfonlin http://www.tandfonline.com/loi/utrb2 e.com/loi/utrb20 0

On the Analysis of o f Die Wear in Wire-Drawing Process Abdelkader Haddi , Abdellatif Imad & Guillaume Vega To cite this article:  Abdelkader Haddi , Abdellatif Imad & Guillaume Vega (2012) On the  Analysis of Die Die Wear in Wire-Drawing Wire-Drawing Process, Tribology Transactions, Transactions, 55:4, 466-472, DOI: 10.1080/10402004.2012.671451

To link to this article: http://dx.doi.org/10.1080/10402004.2012.671451

Published online: 30 Apr 2012.

Submit your article to this journal

Article views: 200

View related articles

Full Terms & Conditions of access and use can be found at http://www.tandfonline.com http://www.tandfonline.com/action/journalIn /action/journalInformation?journa formation?journalCode=utrb20 lCode=utrb20 Download by: [Indian by: [Indian Institute of Technology Kanpur]

Date: 03 Date: 03 April 2017, At: 21:54

Tribology Transactions, 55:  466-472, 2012 C Society of Tribologists and Lubrication Engineers Copyright  ISSN: 1040-2004 print / 1547-397X online DOI: 10.1080/10402004.2012.671451

On the Analysis of Die Wear in Wire-Drawing Process ABDELKADER HADDI,1,2 ABDELLATIF IMAD,1,3 and GUILLAUME VEGA4 1Universite ´  Lille Nord de France F-59000 Lille, France 2Laboratoire Genie ´  Civil et g´  eo-Environnement (LGCgE) Universit´  e d’Artois Facult´  e des Sciences Appliqu´  ees F-62400 B´  ethune, France 3 ´  Laboratoire de Mecanique de Lille CNRS UMR 8107 Universite´  de Lille 1 Avenue Paul Langevin F-59655 Villeneuve d’Ascq, France 4Nexans Research Centre Boulevard du Marais BP39, F-62301 Lens France

 In the present article, the wire-drawing process is investi-

(Saanouni (3); Norasethasopon and Yoshida (4)). Dominant factors influencing die wear are the wear coefficients between the die and the wire, the surface pressures of the die, and the relative length movement between the die and the wire (Archard (5)). Knowledge and control of wear often leads to successful metalforming operations. According to Wistreich (6), wear is most severe at the first contact point of the die. The author assumed that a “wear ring” occurs in the first contact point between the wire and the die. Ali, et al. (7)  indicated that the die wear is affected by the lubrication conditions and the contact time between the workpiece and the die. Various models of friction/lubrication have been developed for cold metal rolling, drawing (Le and Sutcliffe (8), (9)), and extrusion processes (Hsu, et al.  (10)) under different lubrication conditions. The active lubrication regime and appropriate friction factor were determined from the current local values of interface variables such as mean lubricant film thickness and workpiece and tooling roughness, in addition to the more traditional external variables such as interface pressure and strain rate of the workpiece. Kim, et al. (11) analyzed the die wear in cold wire drawing processes and compared the results of  simulations and tests. To understand the wear mechanisms, friction measurements between steel wire and tungsten carbide dies were performed by Hollinger, et al. (12). Their studies confirmed that die wear is related to the heat generated in the contact zone during the forming process and that changes in lubricants can significantly improve die life. The wear mechanisms of ceramic drawing dies were investigated by Jianxin, et al.   (13). They observed that the most common failure of ceramic drawing dies is wear at its approach zone. Christiansen and De Chiffre (14) analyzed progressive wear and other surface alteration processes that take place in deep-drawing dies. They found that the maximum wear takes place at angular positions of 20 and 70◦ along the die corner radius, with the minimum at 45◦ . Gillstr ¨  om and Jarl  (15)

 gated in order to estimate die wear using an experimental ap proach. Experiments were carried out on a drawing machine involving industrial conditions. Dies made from tungsten carbide were examined using macroscopic and microscopic observations to measure the wear ring located at thewire–die contact. Two types of wires were used in this work: aluminum and cop per materials. The results obtained show that the die wear rate has significant effects on the tolerances of the wire and on the die life. KEY WORDS

Wire Drawing; Wear Rate; Experiment

INTRODUCTION In the wire-drawing process, the cross section is reduced by forcing the wire through a series of dies. The drawing die is the most critical part, because it gives the final shape of the wire. In the wire-drawing process, the die angle, coefficient of  friction, and area reduction have a major influence on stress inhomogeneity and the wire quality as well as die wear (Bandar, et al.  ( 1); Vega, et al.  ( 2)). Die wear is the predominant factor affecting tool life in the drawing process by thermal load and wire–die contact during the deformation process. The prediction of die life is very important to achieve good quality of finished products. The die wear in a wire-drawing process has significant impacts on the wire industry (wire breaks, short die life, diameter of wire out of tolerance), and the replacement of dies takes time Manuscript received August 4, 2011 Manuscript accepted February 20, 2012 Review led by Al Segall

466

Analysis of Die Wear in Wire-Drawing Process

evaluated the difference in die wear using wire rods descaled by two different treatments, pickling and reversed bending. The results indicated that the die in the sixth draft had wear an order of  magnitude lower compared to the die in the first draft. Recently, thermomechanical analysis has been studied to characterize the interface conditions between the wire and die and to predict the temperature distribution at the die exit in a wire-drawing process (Celentano   (16); Haddi, et al.   (17)). The temperature increase was generated by both friction and plastic deformations, which have significant effects on die wear. The main goal of this article is to evaluate the die wear using experimental approach in order to estimate tool life and to predict the possibility of repairing or changing the die in wire-drawing processes. The remainder of this article is organized as follows. The following section presents the materials and experiments. The next section is devoted to the presentation of results and comments on two types of wires, aluminum and copper. Finally, the major conclusions are summarized in the final section.

467

MATERIALS AND EXPERIMENTS Experimental investigations of the wire-drawing process involved the measurement of die wear using an industrial multipass drawing machine for all of the drawing experiments mentioned in this article. It was not possible to study the die wear for a determined quantity of drawn material, in terms of tonnage or drawn length at similar drawing speed. Die wear can be divided into three zones. The first wear zone is around the first contact point between the wire and die. The second wear zone is the working cone and the third is the bearing at the die exit (Fig. 1). The industrial drawing machine consists of capstans around which wire is wound between two consecutive drawing operations. Winding creates enough friction between the wire and capstan to transmit the drawing force that pulls the wire through series of dies. For each pass, the wire diameter decreases and the drawing speed increases. For this purpose, aluminum alloy and copper materials were used. These materials correspond to geometries usually used in

Fig. 1—Multipass drawing machine: (1) first contact point zone, (2) working cone zone, and (3) bearing zone. (color figure available online.)

468

A. HADDI ET AL.

TABLE 1—WIRE AND DIE  MATERIALS

RESULTS AND DISCUSSION

Material Drawn

Die Material

Wire Diameter (mm)

Drawing of Aluminum Alloy

Aluminum alloy 1370 Al (97% Al) Copper Electrolytic Tough Pitch (ETP) (99% Cu)

Tungsten carbide

9.5–3.5

A multipass drawing machine (SAMP) was used to carry out tests involving industrial conditions. The wire was drawn from a 9.5- to 3.5-mm diameter with a velocity of 15 m/s. The whole drawing system (capstans, dies) was fully immersed in a pure oil lubricant. During the wire-drawing process, a cooling system was used to dissipate the heat generated by plastic deformation and friction at the die–material interface. The aim of this system is to keep the temperature between 40 and 50◦ C and consequently save properties of the lubricant. An excessive temperature increase during the wire-drawing process has a direct impact on the mechanical properties of the drawn wire and decreases the viscosity of lubricant. Therefore, the thickness of the oil film is reduced, leading to an increased coefficient of friction (Lee, et al. (19)). This phenomenon may cause severe die wear at the working cone and bearing zone. Experimental investigations of the die fall into two parts: first, measurement of the diameter of the dies and weight of the dies before and after drawing and, second, the microscopic observations obtained by SEM. Dies were taken from an industrial plant after drawing 3.840 tons of product. Table 3 presents the results obtained for seven different dies before and after aluminum wire drawing. From these results, it is shown that the evolution of diameter corresponds to a slight decrease in diameter due to a metallization of aluminum particles contained in the lubricant. Moreover, the die weight increased after 3.84 tons of aluminum alloy wire drawing. Results of the die diameter and weight measurements are given in Table 3 and Fig. 2. All surfaces on the die were polished before wire drawing for good plastic material flow and low friction values and cleaned after wire drawing for more accurate measurement of diameter and weight. The variation in diameter of die as a function of weight change is shown in Fig. 2. The variation in diameter at the fifth (A5) and seventh passes (A7) had different values compared to other dies. These dies showed a

3–1.8

the wire-drawing industry and the test proposed requires the manufacturd of dies (see Table 1). Table 2 shows the mechanical properties of the wire. The aluminum alloy wire was drawn from a 9.5 to 3.5 mm diameter using a drawing machine with a lubrication system by immersion (whole oil). The copper wire was drawn from a 3 to 1.8 mm diameter. The oil–water emulsion has been used as a lubricant and sprayed on dies and wires. The die geometry was characterized by angle α  and area reduction r  = 1  − (R f /Ri )2, where  R i and  R f  are the initial and final radii (Fig. 1). The die was composed of a die core made of tungsten carbide (WC) inserted in a metallic casing. The chemical composition of  the used die material is as follows: cobalt 8%, tungsten 87%, and carbon 5%. Tungsten carbide die is the essential part in the drawing machine to provide a final wire diameter whose geometry is defined with accurate requirements. A recent investigation has indicated promising friction and wear properties for WC-Ni and WC-Co cemented carbide in dry sliding contacts (Bonny, et al. (18)). The dimensions of die were measured on a profile recorder (Conoptica, Electro Optical Frame Cu10) before and after the wire-drawing process. The profile recorder provides readings of  die approach angle, diameter, ovality, and bearing length. After drawing, dies worn during the drawing process were analyzed by scanning electron microscopy (SEM). The wear process has been described by Archard’s wear model (Archard  (5)). This model, used to predict die wear in the wire-drawing process, is given by the equation

W  =

0.08

V  kF n = L 3H 

0.07

where  W  is the worn volume per unit sliding distance, V  is the volume of the material removed by wear from the surface, L  is the sliding distance, k   is a constant depending on the material combination and contact conditions,  F n  is the normal pressure, and  H   is the hardness of the die.

TABLE 2—MECHANICAL P ROPERTIES OF  WIRE

   )   m0.06   m    (   n 0.05   o    i    t   a    i   r   a 0.04   v   r   e    t   e 0.03   m   a    i    D0.02 0.01

Young’s Modulus (MPa)

Yield Stress (MPa)

Ultimate Strength (MPa)

Fracture Strain (%)

69,000

195

240

10

120,000

320

350

6

0 0

0.05

0.1

0.15

0.2

0.25

Die weight variation of (kg)

Aluminum alloy Copper

Fig. 2—Variationin diameter of die related to weight change after3.8 tons of aluminum alloy wire drawing.

Analysis of Die Wear in Wire-Drawing Process

469

TABLE 3—R ESULTS OF THE  WEAR  TESTS FOR  3.84 T ONS OF  ALUMINUM ALLOY WIRE  DRAWING Before drawing Die diameter (mm) Entry wire Die number Al A2 A3 A4 A5 A6 A7

Reduction rate r (%)

9.5 8.32 7.23 6.25 5.44 4.7 4.08 3.5

After drawing Die diameter (mm)

Reduction rate r (%)

Diameter variation

Before drawing Die weight (g)

After drawing Die weight (g)

Weight Variation

23.65 24.58 25.51 25.59 24.50 26.03 24.25

−0.019

307.16 263.59 280.49 274.02 241.86 279.66 253.79

307.30 263.76 280.66 274.20 242.00 279.85 253.95

0.1430 0.1710 0.1740 0.1800 0.1400 0.1920 0.1620

9.5 23.30 24.49 25.27 24.24 25.36 24.64 26.41

8.30 7.21 6.22 5.37 4.66 4.01 3.49

decreased variation in die diameter related to the increased sliding distance. This is because the lubricant was sprayed on die A7, whereas dies A1–A6 were immersed in lubricant. Furthermore, the reduction rate decreasedby about 1% between dies A3 and A4 and increased by about 1% between A4 and A5. A similar phenomenon was also observed between dies A5, A6, and A7. The results show a linear correlation between variation in diameter and variation in weight. Figure 3 shows the wear ring observed for die A4 with a diameter of 5.44 mm, which corresponds to the highest variation in diameter. It should be noted that the presence of a wear ring is clearly observable at the first point of the wire–die contact. Microscopic observations of die at the first wire–die contact are shown in Fig. 4. The defect is 640 µ m wide and 27  µ m deep. The tungsten carbide dies for this type of aluminum alloy wire and the diameter range are changed around 500 km of drawn wires.

Fig. 3—Wear ring located at the wire–die contact for die A4. (color figure available online.)

−0.021 −0.028 −0.073 −0.037 −0.069 −0.009

TABLE 4—DIE  WEAR  R ATE  R ESULTS Die numbers Al A2 A3 A4 A5 A6 A7

Diameter Variation −0.019 −0.021 −0.028 −0.073 −0.0365 −0.069 −0.009

Sliding distance (km)

Drawing speed (m/s)

Worn volume (mm3)

Wear (mm3/m)

26 35 46 61 82 109 148

2 .76 3 .6 4 .77 6 .4 8 .44 11 .3 15

0.25 0.24 0.27 0.62 0.27 0.44 0 .05

9.53E-06 6.80E-06 5.96E-06 1.02E-05 3.27E-06 4.02E-06 3.34E-07

The wear rate of seven dies after 3.840 tons of wire drawing is summarized in Table 4 and Fig. 5. The effect of the sliding distance on wear rate  W   is shown in Fig. 5 for aluminum material in the bearing zone. The results show that the wear rate decreased with increasing sliding distance and worn volume. This may be explained by the presence of a metallic transfer inside the dies. Indeed, aluminum is transferred to the die surface during wiredrawing process. A slight augmentation of wear was observed at fourth pass (A4). This can be explained by a 1% decrease in the reduction rate compared to die A3; that is, from 25.27 to 24.24%. A similar phenomenon was observed between die numbers A5 and A6. The lowest die wear occurred at the seventh pass (A7).

Fig. 4—SEM observations of die wear at the first wire–die contact for die A4: width  640 µm, depth  27 µm. (color figure available online.) =

=

470

A. HADDI ET AL.

-7

-6

(x 10 ) 10

(x 10 ) 12

Experimental data Linear regression

10

   )   m    /    3   m 8   m    (   e    t   a 6   r   r   a   e    W 4

9    )   m    /    3   m 8   m    (   e    t   a   r 7   r   a   e    W 6

2

5 200

0 0

20

40

60

80

100

120

300

140

400

500

600

Sliding distance (km)

Sliding distance (km) Fig. 5—Variation in die wear rate withslidingdistancefor aluminum wire.

This die was sprayed with lubricant, whereas the others were immersed in lubricant.

Drawing of Copper The copper wire was used, allowing a reduction in wire diameter from 3 to 1.8 mm using four tungsten carbide dies. Drawing speed was about 26 m/s and the whole drawing system was fully immersed in oil–water emulsion lubricant. Oil systems have cooling capabilities that reduce fluid temperature. However, if the contact area is significant, friction increases, creating an excessive temperature increase at the die–wire interface (average temperature up to 100◦ C at drawing speed of about 20 m/s). This increase in contact temperature can lead to a loss of viscosity of  the lubricant film. A similar observation of the wire–die contact related to the steel wire-drawing process has been reported previously (Hollinger, et al. (12)) where two emulsions, A and B, were used to examine the lubricant effect. In the present study, to improve lubricant efficiency, a cooling system was used in order to maintain the temperature of lubricant around 38◦ C. The experimental investigations of the die wear of copper wire involved the measurement of the diameter and weight of the dies

Fig. 7—Die wearrate versus slidingdistance forcopperwire. (color figure available online.)

before and after the drawing process. Dies were taken from an industrial plant after drawing 12 tons of products. In this part, the measurement results showed that variation in die diameter increased after each pass. In Table 5, in the first die C1, the diameter of the incoming wire was 3 mm. For the first pass, the diameter of the unused die was 2.6 mm and worn diameter was 2.65 mm. In this case, the change in die diameter increased by 0.05 mm. In the second die, C2, the incoming wire diameter was the same as the outgoing from die C1. The diameter of the unused die was 2.3 mm, the worn diameter was 2.38 mm, and the change in diameter increased by 0.08 mm. For dies C3 and C4, the variation in diameter increased by 0.12 and 0.16 mm, respectively. The variation in diameter ranged from 0.05 to 0.16 mm. From these results, it is shown that the final die diameter was out of tolerance due to die wear. It should be noted that for die C4, the desired diameter was 1.8 mm, whereas the obtained diameter after 12 tons of wire drawing is 1. 96 mm. This seems consistent with a slight decrease in die weight after drawing (cf. Table 5). Figure 6 confirms this finding, because a slight increase in the variation in diameter was measured after drawing 12 tons of wire to obtain a 12 µm wear at the first contact point. Once

Fig. 6—Observation of deformed bearing zone and die wear at the working cone. (color figure available online.)

Analysis of Die Wear in Wire-Drawing Process

471

TABLE 5—RESULTS OF THE  WEAR  TESTS FOR  12 T ONS OF  COPPER WIRE  DRAWING Before drawing Die diameter (mm) Entry wire Die number Cl C2 C3 C4

Reduction rate r (%)

3

After drawing Die diameter (mm)

Reduction rate r (%)

Diameter variation

Before drawing Die weight (g)

After drawing Die weight (g)

Weight Variation

21.97 19.34 20.66 14.52

0.05 0.08 0.12 0.16

515.76 520.03 514.69 518.86

515.05 519.97 514.69 518.81

−0.71

3

2.6 2.3 2 1.8

24.89 21.75 24.39 19.00

2.65 2.38 2.12 1.96

TABLE 6—DIE WEAR  RESULTS FOR  COPPER MATERIAL Die numbers Cl C2 C3 C4

   

Diameter variation

Sliding distance (km)

Drawing speed (m/s)

Worn volume (mm3)

Wear (mm3/m)

0.05 0.08 0.12 0.16

268 342 453 560

11.5 15.4 19.66 26

0.2060625 0.293904 0.388104 0.472256

7.69E-07 8.59E-07 8.57E-07 8.43E-07

   

   

−0.06

0 −0.05

A slight decrease in die diameter was observed for aluminum alloy due to metallization of the aluminum contained in the lubricant. For copper wire, a slight increase in the variation in diameter can be attributed to die wear in the bearing zone. Finally, the amount of aluminum or copper wire to be drawn is enormous, so the die wear rate must be maintained as low as possible in order to ensure that the final diameter of the wire is not out of tolerance.

REFERENCES the wear ring appeared at the entry of working zone, the wear rate increased rapidly in the bearing area. Therefore, wear in the bearing area has the direct effect of producing out-of-size wire. The wear rate of the dies after 12 tons of copper wire drawing is summarized in Table 6 and Fig. 7. The effect of sliding distance on the wear rate in the bearing zone is shown in Fig. 7 for the copper wire-drawing process. The wear rate increased with sliding distance and reached a slightly stable value. The change in wear per distance implies a change in the diameter of the die. This variation could be caused by a wear mechanism, defined as a slow degradation of the die surface caused by friction between the die and the copper wire. Die wear is related to the presence of copper transfer on the tool surface. These conditions led to cobalt binder consumption and then to decohesion wear of the die material characterized by grains, or grain clusters, stripping (Lepadatu, et al.(20); Pirso, et al. (21)). The quality of the copper surface is governed by the state of the WC die wear.

CONCLUSIONS Experimental studies were carried out to assess tungsten carbide die wear for aluminum alloy and copper wires. Die wear was analyzed using a profile recorder and SEM. The important points emerging from this study are as follows:

   

   

   

The most common failure of the drawing die is wear at the working and bearing zones. The morphology of dies shows the existence of a die wear whose importance depends on drawn wire length. Two sets of dies were analyzed. The first one corresponds to a few kilograms of aluminum wire drawn with pure oil lubricant, leading to very low wear of the final dies. The second case corresponds to several kilograms of copper wire drawn, but oil–water emulsion lubricant was used, causing significant die wear.

(1) Bandar, A. R., Gifford, R. B., Misiolek, W. Z., and Coulter, J. P. (2004), “Impact of Die Geometry on Microhardness and Grain Size of ColdDrawn Steel Wire,”   Materials and Manufacturing Processes , 19(3), pp 507–521. (2) Vega, G., Haddi, A., and Imad, A. (2009), “Investigation of Process Parameters Effect on the Copper-Wire Drawing,”  Materials & Design,  30, pp 3308–3312. (3) Saanouni, K. (2008), “On the Numerical Prediction of the Ductile Fracture in Metal Forming,”   Engineering Fracture Mechanics, 75, pp 3545– 3559. (4) Norasethasopon, S. and Yoshida, K. (2008), “Prediction of Chevron Crack Initiation in Inclusion Copper Shaped-Wire Drawing,”  Engineering Failure Analysis,  15, pp 378–393. (5)  Archard, J. F. (1953), “Contact and Rubbing of Flat Surfaces,”  Journal of   Applied Physics,  24, p 981–988. (6)  Wistreich, J. G. (1958), “The Fundamentals of Wire Drawing,”  International Materials Reviews,  3 , pp 97–142. (7)  Ali, S. M. J., Rooks, B. W., and Tobias, S. A. (1971), “The Effect of Dwell Time on Die Wear in High Speed Hot Forging,”  Proceedings of the Institution of Mechanical Engineers,  185, p 1171–1186. (8) Le, H. R. and Sutcliffe, M. P. F. (2000), “A Two-Wavelength Model of Surface Flattening in Cold Metal Rolling with Mixed Lubrication,”  Tribology Transactions,  43, pp 595–602. (9)   Le, H. R. and Sutcliffe, M. P. F. (2001), “A Semi-Empirical Friction Model for Cold Metal Rolling,”   Tribology Transactions, 44, pp 284– 290. (10) Hsu, T. C.,Li, Y. M.,and Hung,C. H. (2000), “A MixedLubricationModel for Computer Simulation of Extrusion Processes,”  Tribology Transactions, 43, pp 781–787. (11)  Kim, T. H., Kim, B. M., and Choi, J. C. (1997), “Prediction of Die Wear in the Wiredrawing Process,”  Journal of Materials Processing Technology, 65, pp 11–17. (12) Hollinger, S., Depraetere, E., and Giroux, O. (2003), “Wear Mechanism of  Tungsten Carbide Dies during Wet Drawing of Steel Tyre Cords,”  Wear , 255, pp 1291–1299. (13)  Jianxin, D., Xuefeng, Y., and Jinghai, W. (2006), “Wear Mechanisms of  Al2 O3 /TiC/Mo/Ni Ceramic Wire-Drawing Dies,”  Materials Science and Engineering A,  424, pp 347–354. (14)  Christiansen, S. and De Chiffre, L. (1997), “Topographic Characterization of Progressive Wear on Deep Drawing Dies,”  Tribology Transactions,  40 , pp 346–352. (15)   Gillstr ¨  om, P. and Jarl, M. (2007), “Wear of Die after Drawing of Pickled or Reverse Bent Wire Rod,”  Wear ,  262, pp 858–867. (16)  Celentano, D. J. (2010), “Thermomechanical Simulation and Experimental Validation of Wire Drawing Processes,”  Materials and Manufacturing Processes,  25 (7), pp 546–556.

472

A. HADDI ET AL.

(17) Haddi, A., Imad, A., and Vega, G. (2011), “Analysis of Temperature and Speed Effects on the Drawing Stress for Improving the Wire Drawing Process,”   Materials & Design, 32, pp 4310– 4315. (18)  Bonny, K., De Baets, P., Vleugels, J., Huang, S., and Lauwers, B. (2009), “Tribological Characteristics of WC-Ni and WC-Co Cemented Carbide in Dry Reciprocating Sliding Contact,”   Tribology Transactions, 52, pp 481–491.

(19)  Lee, S. K., Lee, S. B., and Kim, B. M. (2010), “Process Design of MultiStageWet Wire Drawing forImproving theDrawing Speed for0.72wt% C Steel Wire,” Journal of Materials Processing Technology,  210, pp 776–783. (20) Lepadatu,D., Hambli, R.,Kobi,A., andBarreau,A. (2006), “Statistical Investigation of Die Wear in Metal Extrusion Processes,”  International Journal of Advanced Manufacturing Technology ,  28, pp 272–278. (21)  Pirso, J., Letunovits, S., and Viljus, M. (2004), “Friction and Wear Behaviour of Cemented Carbides,”  Wear ,  257, pp 257–265.