FEEDING SYSTEM DESIGN OF DUCTILE IRON DI

FSD – Feeding System Design – DUCTILE IRON

INTRODUCTION

Computers are excellent instruments for storing and retrieving data, and for performing the

mathematical calculations with that data, or with other supplied information. The use of computer

in gating and risering design does not eliminate the need for someone to plan, provide

reasonable data and evaluate the output. However, we tried so hard to control the input data by

adding logical limitations for each input value.

THE OBJECTIVES:

Getting the optimal design of gating and risering system which provides high quality castings

without shrinkage defects (since the sand properties are controlled and the iron quality is

good).

Improving the yield by using the minimum riser size capable of feeding the casting properly.

That also improves the production economy by increasing the number of castings per one

batch of molten metal.

1.0 RISERING SYSTEM DESIGN

RISER DESIGN, or risering, deals with the development of suitable reservoirs of feed metal in

addition to the desired casting shape so that undesirable shrinkage cavities in the casting are

eliminated.

1.1 Ductile Iron Solidification

There are three stages of solidification volume change, and rational risering practice takes

account of them. They are:

A volume decrease of the liquid metal as soon as it has been poured, while it cools to the

temperature of eutectic solidification.

A volume increase during eutectic solidification, when graphite nodules grow and exert

considerable expansion pressure on the mold. The net volume increase can produce a liquid pressure of (2

MPa) in the mould. This pressure always exceeds the elastic limit of the mould, except for very rigid

moulds, leading to mould enlargement and swollen castings, often containing shrinkage defects.

Green sand moulds are not considered to be rigid.

A volume decrease during the last stage of solidification (secondary shrinkage).

Volume change pattern is not constant but varies according to cooling rate and liquid iron

processing route (superheat, charge composition, melting method, inoculation, etc.).

1.2 Cooling rate

Casting weight or wall thickness is not sufficiently accurate to describe cooling rate.

Simple shapes: cube, plate, bar, all 25 mm thick but all cool at different rates.

The volume-to-area ratio of the casting is termed the casting modulus, Mc ;

.

More complicated shapes should be broken down into simple shapes and the moduli of the

individual simple shapes, determined.

1.3 Optimum Riser Design

The role of the methods engineer in designing risers can be stated simply as making sure that

risers will provide the feed metal:

In the right amount

At the right place

At the right time

Riser – always “blind” (closed top). Riser contact (Neck) – generally is as short as possible.

Designed dimensions always measured at the notch.

Riser function is very sensitive to pouring temperature and pouring time.

1.4 Planning

Determine significant modulus of the castings (M c).

Select appropriate risering method.

Determine corresponding liquid transfer modulus (M N) and number of risers required for each

casting.

Select riser type and compute dimensions (M R).

Select riser contact (neck) type and compute dimensions.

Check that available feed volume in riser(s) is sufficient for casting’s requirements.

Select pouring temperature based on selected risering method.

1.5.0 Selection of Risering Method

Selection is based on mould strength and casting modulus.

Methods take advantage of the fact that graphitic irons expand during cooling.

There are three basic applied risering methods:

Pressure control risering (PCR).

Directly applied risering (DAR).

Riserless.

Application of each method:

When mould is weak (Green Sand) and casting modulus is greater than 4 mm we’ll use PCR.

When mould is strong (Furan Sand) and casting modulus is less than 25 mm or when mould is weak

(Green Sand) and casting modulus is less than 4 mm we’ll use DAR.

When mould is strong (Furan Sand) and casting modulus is greater than 25 mm use RISERLESS.

1.5.1 Pressure Control Risering (PCR)

Objective is to control the pressure generated

during cooling and solidification, between a

minimum pressure level, which will prevent the

occurrence of secondary contraction defects

and a maximum level, at which the mould will

enlarge.

Principles of PCR:

a) After pouring completed, liquid contracts.

b) Riser compensates for liquid contraction.

c) When expansion starts, mould deformation avoided by pressurized liquid from

casting, “bleeding back” to refill the (blind) riser.

Ideally riser should refill just before expansion ceases.

This puts all remaining liquid under slight positive pressure and prevents secondary shrinkage

defect.

1.5.1.1 Determine corresponding liquid transfer modulus (MN) and riser modulus (MR)

The transfer modulus (MN) is the modulus required of the riser neck to remain open as long as

liquid transfer is necessary. The next graph shows the relationship between the significant

modulus of the casting and the transfer modulus as influenced by iron quality. In our

program, we are calculating the transfer modulus as the iron quality is average.

Once the transfer modulus has been determined, the riser modulus is calculated

according to this ratio:

1.5.1.2 Riser Type and Riser Calculation

There are three standardized riser types:

Side Riser, Cope Connection (Neck in Cope)

Side Riser, Drag Connection (Neck in Drag)

Top Riser

All Riser dimensions are a function of the riser diameter (DR): Riser height (HR) = 1.5 x DR

Riser Contact (Neck):

The shape of riser neck must be selected as round, square or

rectangular and the dimensions of the riser neck are

calculated using the transfer modulus MN:

Round or Square Neck = 4 x MN

Rectangular Neck = 3 x MN (thickness) & 6 x MN (width)

Riser neck dimensions are measured at the bottom of the

radius between riser and casting. Additional notching of the

contact may be introduced providing the additional notch

depth is not more than one fifth contact thickness.

1.5.1.3 Liquid Feed Metal Requirements (FMR) and Effective Feed Metal of the Riser (EFM):

Thus far, the riser design has been based strictly on modulus or cooling rate. The riser dimensions

were calculated to ensure that the riser would remain active for as long as liquid transfer is

necessary. However, there has not been any consideration for the volume of liquid iron required

to compensate for the contraction of the liquid in the casting / riser complex.

To ensure that there is adequate feed metal in that portion of the riser which is higher than the

highest point of the casting, a volume check of the riser is required. The next graph shows the

relationship between the percent feed metal required by casting FMR and its modulus MC.

To Calculate the Effective Feed Metal of the riser:

If the effective riser volume exceeds the volume of the feed metal required by the casting, the rise

design based on modulus is satisfactory. If not; riser dimensions will be increased.

2.0 GATING SYSTEM DESIGN

2.1 Optimum Gating System Design

Fast pouring to: Minimize temperature loss during mould filling.

Clean pouring to: Avoid slag (dross) generation during pouring.

Economic Design: Maximize casting yield.

2.2 Planning

Generate a basic layout by considering:

optimum space utilization for castings

chosen risering method

place parting to minimize need for cores

castings located in cope

simple, symmetrical system

identical gating and risering for identical castings

use one riser for more than one casting if possible

Leave room on plate for adequate gating and risering system.

2.3 The Role of "CHOKE"

Choke is that cross sectional area in a gating system which

determines mould filling time. Choke located at junction of runner

and gate in a simple GATE-RUNNER (pressurized) system. The total

choke cross sectional area is the sum of individual gate cross

sectional areas: Total choke = Ac = A1 + A2 + ... An

2.4 Friction

Not all potential energy of liquid at top of sprue is converted to mechanical energy at casting

cavity.

Some potential energy lost to friction (heat) as liquid moves against mould wall and liquid

moves against liquid.

Energy loss due to friction extends mould filling time and must be taken into account when

calculating choke cross sectional area and pouring time.

2.5 Pouring time

As fast as possible consistent with human ability and production routine. very approximate guide,

√( ) (W = weight of castings + risers + Gating system).

2.6 Choke Cross Sectional Area (Ac.)

Velocity of iron stream at choke is √

√ [

√

√ √( )

]

Gate Dimensions; NG : Number of gates for each casting

Gate Thickness: √

& Gate width=4a

Runner bar Dimensions; Runner Sectional area

Width of runner = √

Height of runner =√

Sprue size:

√

3.0 SOFTWARE ALGORITHM

3.1 Introduction: Before building the algorithm, the basic options were specified:

Pattern Assembly options:

- One Casting per Mold

- Multiple Castings per Mold

- Different Castings per Mold

Risering options:

- One riser per casting

- Multiple risers per casting

- Shared riser

3.2 Input Data:

Weight of the casting WC – Modulus of the casting MC – Height of the casting in cope HC cope.

Directly calculating the total weight of the castings:

Volume of the casting:

3.3 Risering System Design: One or Multiple Castings Per mold with all Risering Options – Iron

Quality: Average – Risering Method: Pressure Control Risering (PCR)

By selecting the risering option, the volume of metal required from the riser will be determined as

shown in the previous flow chart.

3.3.1 Calculating FMR %: As mentioned before, the relationship - between the modulus of casting

and the feed metal required - is shown in the next graph as 2 curves according to metallurgical

quality: Poor and good quality.

In our program we will calculate the feed metal required for the average quality, so we have

drawn the middle curve as a reference for the average quality and then divided this curve into

small lines to find an approximation linear relation between casting modulus and the feed metal

required %. Five equations were found as the following:

𝐶 ≤ 0.3 𝑐𝑚: % 𝑅 = 1.6667 𝐶+4

0.3 < 𝐶 ≤ 0.8 𝑐𝑚: % 𝑅 = 𝐶+3.8

0.8 < 𝐶 ≤ 1.6 𝑐𝑚: % 𝑅 = 0.625 𝐶+3.5

1.6 < 𝐶 ≤ 2.4 𝑐𝑚: % 𝑅 = 0.375 𝐶+3.1

𝐶 > 2.4𝑐𝑚: % 𝑅 = 2.2

After determining the feed metal required (FMR %), we can calculate the volume of metal

required for one casting; 𝑅 . Then the user should select risering option (that means;

the user will select either separate riser/s or shared riser/s)to calculate number of risers and the

volume of metal required from each riser VMRR.

3.3.2 Calculating transfer modulus (MN) as a function to Modulus of casting (MC): As shown in

the next graph; we divided the curve into lines to find an approximation linear relation between

casting modulus and transfer modulus. Four equations were found as the following:

≤ 𝐶 ≤ 𝑐𝑚: = 0.28 𝐶 + 0.37

1 < 𝐶 ≤ 𝑐𝑚: = 0.3 𝐶 + 0.35

1.5 < 𝐶 ≤ 𝑐𝑚: = 0.4 𝐶 + 0.2

2 < 𝐶 ≤ 8 𝑐𝑚∶ = 0.5 𝐶

3.3.3 Calculating modulus of the riser (MR):

Modulus of the riser MR can be calculated using this equation: . Then, the user selects

the riser type and neck (Contact) shape to calculate riser dimensions. All riser dimensions are a

function of the riser diameter (DR).

3.3.4 Calculating riser dimensions:

Diameter of riser changes according to riser type:

Side riser – neck in cope: ,

Side Riser – Neck in drag: ,

Side Riser – Split Neck: ,

Top Riser: In PCR method which we use it in green sand only, and for our green sand

Automatic moulding machine (Match plate type), it’s not possible to use top riser within this

machine. So, we will use top risers with another risering method.

3.3.5 Calculate the Effective Feed Metal of the riser:

3.3.6 Riser Check:

EFM>VMRR

3.3.6.1 If EFM>VMRR:

The riser design has been based on modulus of the casting (cooling rate) taking into

account the volume of liquid iron required to compensate for the contraction. This design

should work properly.

3.3.6.2 If EFM<VMRR:

In this case, the Riser design with the initial calculations is not sufficient to compensate for

the contraction.

We should not increase the riser size randomly; we suggested new way to solve this

problem. We will calculate the riser diameter that makes the effective feed metal equals

the volume of metal required from the riser, this diameter was called critical diameter Dcr.

Then, we will determine modulus of the riser with the maximum limits. By determining

maximum modulus MRmax of the riser, we will calculate the maximum riser diameter Dmax

and then compare it with the critical diameter.

3.3.6.2.1 Calculating DR max

To calculate Dmax we have to find the maximum transfer modulus (MN max) which still

achieves the proper work of the riser, and for that we re-divided the curve with the

maximum limits into four lines to find an approximation linear between casting modulus and

transfer modulus. Four equations were found as the following:

≤ 𝐶 ≤ 𝑐𝑚: max = 0.8

1 < 𝐶 ≤ 𝑐𝑚: max = 0.4 𝐶 + 0.4

1.5 < 𝐶 ≤ 𝑐𝑚: max = 0.7 𝐶 – 0.05

2 < 𝐶 ≤ 8 𝑐𝑚∶ max = 0.5417 𝐶 + 0.2667

After that we can calculate MR max and DR max

3.3.6.2.2 Calculating Dcr:

( ) ( )

( )

(

) (

)

3.3.6.2.3 Roots of a cubic function:

The general cubic equation has the form

𝑐 & the coefficients a, b, c and d are generally assumed to

be real numbers.

The nature of the roots Every cubic equation with real coefficients has at least one solution x among the real

numbers. We can distinguish several possible cases using the discriminant,

𝑐 𝑐 𝑐

The following cases need to be considered:

If Δ > 0, then the equation has three distinct real roots.

If Δ = 0, then the equation has a multiple root and all its roots are real.

If Δ < 0, then the equation has one real root and two non-real complex roots.

General formula of roots For the general cubic equation (1) with real coefficients, the general formula for the roots,

in terms of the coefficients, is as follows. The expression under the square root sign in what

follows is ( 𝑐 ) ( 𝑐) , where Δ is the above-

mentioned discriminant.

3.3.6.2.4 Riser Check with maximum limits:

By using previous equations; the critical diameter can be calculated. Then we should

compare between the critical and maximum diameters:

Dmax>Dcr

If Dmax > Dcr:

We will calculate riser diameter as the average of critical and maximum diameters.

In some cases; the critical diameter can be so close to the first diameter DR, and when

we take the average between critical and maximum diameters, the riser will be

oversize. So, we will calculate the riser diameter by using:

( );

“ f ” is the approximation factor (0.1-0.9), that means; by changing the approximation

factor between 0.1 to 0.9, riser diameter will be changed, and as a result, the effective

feed metal will also be changed automatically. That helps the user in selecting the

riser diameter without getting oversize riser.

If Dmax < Dcr:

In that case, we will make and change the ratio between diameter and

height of the riser as:

“K” is the height factor, by increasing it between 1.6 to 2, riser height will be changed,

and as a result, the effective feed metal will also be changed automatically.

3.3.7 Neck Size:

The shape of riser neck must be selected as round, square or rectangular and the dimensions of

the riser neck are calculated using the transfer modulus MN:

Round or Square Neck = 4 x MN

Rectangular Neck = 3 x MN (thickness) & 6 x MN (width)

Important notice:

If the effective feed metal was less than the volume of feed metal required from the riser; the

software will calculate the maximum transfer modulus MN max to increase volume of the riser, but for

neck dimensions, the software will use first modulus of transfer MN

3.3.8 Volume of riser:

𝑚 𝐶 𝑐 𝑐 𝐶

(

)

(

) ;

D1: Diameter of the top & D2: Diameter of the base & h: height of the cone

Volume of riser in cope:

Volume of side riser – neck in cope, in drag or split (normal case and Dmax>Dcr):

(

( )

)

Volume of side riser – neck in cope, in drag or split (Dmax<Dcr):

(

( )

)

Volume of riser in Drag:

Side riser – Neck in cope:

Side riser – Neck in drag:

Side riser – Split neck:

3.3.9 Results Analysis:

This part can help the user in checking the results by presenting riser dimensions, feed metal

required and the effective feed metal of the riser. According to selected risering options during

the calculation, this part will give the user a conclusion of the selected options and the results, and

advise him either to continue or to change risering options.

1) If the normal results are good: The results are satisfactory.

The riser design has been based on modulus of the casting (cooling rate) taking into account the

volume of liquid iron required to compensate for the contraction. This design should work properly.

2) If not:

If DR max > Dcr and HR:DR = 1.5:1

The Riser design with the initial calculations is not sufficient to compensate for the contraction. You

have used the maximum limits of transfer modulus to increase riser volume,

o If F<0.5: and you’ve selected the riser diameter with a balance between the maximum limits

and the critical riser design. This design should work properly.

o If 0.8<F<0.5: and you’ve selected the riser diameter near to the maximum limits. This design

may work properly.

o If F>0.8: and you’ve selected the riser diameter close to the maximum limits. We advise you to

change the risering option.

o Dear /USER/; we advise to change the risering option:

IF: One Riser Per mold: Use multi risers per casting if possible

If: multi risers per casting: Increase the number of risers per casting

IF: Shared riser:

If CR=2; use one riser per casting

If CR>2; Decrease the number of castings per shared riser.

If DR max < Dcr and HR:DR = 2:1

The Riser design with the initial calculations is not sufficient to compensate for the

contraction. You have used the maximum limits of transfer modulus to increase riser

volume, but it was not enough, then you’ve changed the ratio HR:DR to 2:1. We advise

you to change the risering option.

3.4 Gating System Design: Gate-Runner System with all risering options

3.4.1 Calculating total pouring weight (kg):

3.4.1.1 Total Pouring weight for multi-risers per casting: ( ) ; f: Factor of

Gating weight, WC :the weight of the casting, WR : The weight of risers; 𝑅 ( )

R: Number of risers per casting, ρ; Iron Density, VRC: Volume of riser in cope, VRD: Volume of riser

in drag

Determining (f) factor of gating weight:

( ) ≤

( ) ≤

≤ ( ) ≤

3.4.1.2 Total pouring weight of Basic castings with one shared riser: ( ) ;

f: Factor of Gating weight, WC :the weight of the basic castings, WR : The weight of riser

( ) & 𝐶𝑅 CR: Number of castings per one shared riser ρ; Iron

Density, VRC: Volume of riser in cope, VRD: Volume of riser in drag.

Determining (f):

( ) ≤

( ) ≤

≤ ( ) ≤

3.4.1.3 Total pouring weight of Residual castings with one shared riser: ( ) ;

f: Factor of Gating weight, WC :the weight of the residual castings, WR : The weight of riser

( ) & i: Number of residual castings, ρ; Iron Density, VRC: Volume

of riser in cope, VRD: Volume of riser in drag.

Determining (f):

( ) ≤

( ) ≤

≤ ( ) ≤

3.4.2 Approximate Pouring Time (sec):

( 𝑐) √ ( ) ( ) ( )

3.4.3 Determining friction factor:

≤ ( ) ≤ ( )

≤ ( ) ≤ ( )

≤ ( ) ≤ ( )

≤ ( )

3.4.4 Total volume in Cope and Drag (cm3):

3.4.4.1 Total volume in cope and drag for multiple risers per one casting

V Total in cope=V C in cope + R *(V riser in cope) V Total in drag=V C in drag + R *(V riser in drag)

3.4.4.2 Total volume in cope and drag for Basic castings with one shared riser:

V Total in cope= (CR * V C in cope) + V riser in cope V Total in drag= (CR * V C in drag) + V riser in drag

3.4.4.3 Total volume in cope and drag for Residual castings with the shared riser:

V Total in cope= (i * V C in cope) + V riser in cope V Total in drag= (i * V C in drag) + V riser in drag

3.4.5 Choke Cross Sectional area (cm2):

√ [

√

√ √( )

]

3.4.6 Gate Dimensions (cm):

Gate Thickness: √

; & Gate width=4a; NG: Number of gates (entered value)

3.4.7 Gate Check: 𝑐𝑚 𝑐𝑚

1. If a < 0.48 cm: decrease the number of gates to (NG-1) & Recalculate √

and check

again (continue decreasing number of gates until 1). Here; If a > 0.79 cm: make a=0.6 cm and

calculate the width

2. If a > 0.79 cm: Increase the number of gates to (NG+1) & Recalculate √

and check

again. Here; If a < 0.48 cm: make a=0.6 cm and calculate the width

3.4.8 Runner Sectional Area (cm2):

3.4.8.1 Runner sectional area (AR) - one or multiple risers per one or multiple castings

Using Balanced feeding:

; N: number of castings per mold & NR: number of runners

Using Un-Balanced feeding: ; NCRi: number of castings take feeding from

runner ( i )

3.4.8.2 Runner sectional area (AR) – shared risers

Using shared Runner/s for basic and residual castings together:

One Runner: [ 𝑅 ]

Two Runners:

[ 𝑅 ]

Using one runner for basic castings and another one for residual castings

𝑅 &

3.4.9 Runner Dimensions (cm):

Width of runner = √

& Height of runner =√

3.5 Casting Yield

3.5.1 Total Pouring Weight

3.5.1.1 Total Pouring Weight for multi-risers per casting:

[ ( )] ;

N: number of castings per mold, WC :the weight of one casting, WR : The weight of risers, WG : The weight of Gating system.

WN : the weight of riser neck

𝑅 ( )

R: Number of risers per casting, ρ; Iron Density, VRC: Volume of riser in cope, VRD: Volume of riser in drag

( )

, ∑ √

√ , (

) [ ( )]

3.5.1.2 Total Pouring Weight for Shared Riser:

[𝑅 ((𝐶𝑅 ) )] [( ) ] ;

R: number of shared risers used, WC : the weight of one casting, CR: the number of casting per one shared riser, WR basic :

The weight of shared riser for basic castings, WR res : The weight of shared riser for residual castings, WG : The weight of

Gating system, WN : the weight of riser neck

3.5.2 Calculate the casting yield

𝐶 𝑐

3.6 Production Parameters

3.6.1 Recommended Pouring temperature

( )

𝑐 ( 𝑐 )

( )

[ ( ) ]

3.6.2 Treatment alloy weight

[ 𝑅

𝑅 𝑐 ]

𝑚

The recovery of magnesium alloy varies between 40% to 60% according to alloy composition,

content of magnesium in the alloy, and treatment process (sandwich).

%S: Initial Sulfur content in the metal should be as low as possible: 0.02%

Residual magnesium content % is related to the modulus of the casting as shown in the next

graph.

Total weight: the weight of the metal to be treated within the treatment ladle.

3.6.3 Nodule Count

Plot shows range of expected nodule counts for good metallurgical quality ductile irons in

dependence of modulus (cooling rate).

This plot was converted into data table according to modulus of the casting

Modulus (inch) Good Quality Average Quality Poor Quality

0.10 320-520 280-320 & 520-610 280>P>610

0.11 310-510 270-310 & 510-590 270>P>590

0.12 305-500 260-305 & 500-570 260>P>570

0.13 300-490 255-300 & 490-560 255>P>560

0.14 290-480 250-290 & 480-550 250>P>550

0.15 283-450 245-283 & 450-525 245>P>525

0.16 275-440 240-275 & 440-510 240>P>510

0.17 265-425 235-265 & 425-490 235>P>490

0.18 250-408 225-250 & 408-470 225>P>470

0.19 240-402 215-240 & 402-465 215>P>465

0.20 235-398 210-235 & 398-450 210>P>450

0.21 225-385 205-225 & 385-430 205>P>430

0.22 218-375 201-218 & 375-410 201>P>410

0.23 212-368 197-212 & 368-405 197>P>405

0.24 209-360 190-209 & 360-400 190>P>400

0.25 205-355 185-205 & 355-390 185>P>390

0.26 202-350 180-202 & 350-385 180>P>385

0.27 199-340 175-199 & 340-380 175>P>380

0.28 195-330 170-195 & 330-370 170>P>370

0.29 190-320 165-190 & 320-360 165>P>360

0.30 185-310 160-185 & 310-350 160>P>350

0.31 182-305 155-182 & 305-340 155>P>340

0.32 180-302 150-180 & 302-325 150>P>325

0.33 178-300 150-178 & 300-320 150>P>320

0.34 172-295 145-172 & 295-315 145>P>315

0.35 168-290 140-168 & 290-310 140>P>310

0.36 164-285 140-164 & 285-308 140>P>308

0.37 160-280 140-160 & 280-305 140>P>305

0.38 155-275 138-155 & 275-300 138>P>300

0.39 152-270 135-152 & 270-298 135>P>298

0.40 150-265 133-150 & 265-290 133>P>290

0.41 145-260 130-145 & 260-288 130>P>288

0.42 140-255 128-140 & 255-285 128>P>285

0.43 138-250 125-138 & 250-282 125>P>282

0.44 136-245 122-136 & 245-280 122>P>280

0.45 133-240 120-133 & 240-275 120>P>275

0.46 133-239 119-133 & 239-270 119>P>270

0.47 130-235 115-130 & 235-265 115>P>265

0.48 127-233 112-127 & 233-262 112>P>262

0.49 125-231 110-125 & 231-260 110>P>260

0.5 122-227 107-122 & 227-257 107>P>257

0.51 122-225 107-122 & 225-255 107>P>255

0.52 121-224 106-121 & 224-254 106>P>254

0.53 120-222 105-120 & 222-252 105>P>252

0.54 118-218 104-118 & 218-245 104>P>245

0.55 115-215 102-115 & 215-240 102>P>240

0.56 112-210 100-112 & 210-235 100>P>235

0.57 110-208 98-110 & 208-230 98>P>230

0.58 109-205 97-109 & 205-228 97>P>228

0.59 109-204 96-109 & 204-225 96>P>225

0.6 108-203 95-108 & 203-223 95>P>223

0.61 108-203 95-108 & 203-223 95>P>223

0.62 107-203 94-107 & 203-223 94>P>223

0.63 107-202 94-107 & 202-222 94>P>222

0.64 106-202 93-106 & 202-221 93>P>221

0.65 106-202 93-106 & 202-221 93>P>221

0.66 105-201 92-105 & 201-220 92>P>220

0.67 105-201 92-105 & 201-220 92>P>220

0.68 105-201 92-105 & 201-219 92>P>219

0.69 105-200 92-105 & 200-218 92>P>218

0.7 105-200 92-105 & 200-218 92>P>218