VF800AT

Cold work tool steel with excellent combination

of toughness and wear resistance for high

performance tools and dies

What is “VF800AT”?

“V” of Villares

“F” of Frio, cold in Portuguese.

800 refer to 8% of Cr content in the steel chemical composition.

“AT” of Alta Tenacidade, high toughness in Portuguese.

Chemical composition

Standard Reference Chemical Composition

Brief Description / ApplicationVillares Metals Grades

AISI ASTMSAE

DINC Mn Cr Mo V W Others

VF800AT 8%Cr grade - 0,85 0,40 8,50 2,10 0,50 - Nb = 0,15

VF800AT belongs to the family of 8% Cr cold work tool steel. The alloy

composition brings to VF800ATIM the capacity of attaining high toughness

combined with good abrasive and adhesive wear resistance.

VD2 D2 ~1.2379 1,50 0,40 12,00 0,78 0,80 - - VD2 is a high-carbon high-chromium cold work tool steel.

VC131 ~D6 1.2436 2.10 0,30 11,50 - 0,20 0,70VC131 is a high carbon and a high chromium cold work tool steel with an

exceptional resistance to abrasion and maximum cutting stability.

Typical Application

The applications of VF800AT steel are listed below:

Thread roller rolls; Screw-thread chasers; Punching tools; Dies for cutting and spinning; Slitters.

This grade is excellent for cold work applications which demand adhesive wear resistance and high toughness.

44

46

48

50

52

54

56

58

60

62

64

100 150 200 250 300 350 400 450 500 550 600 650

T em p era tu ra d e Reven im en to (°C )

Du

rez

a (

HR

C)

V F -800A T aust. 1070 ºC

V F -800A T aust. 1030 ºC

D 2 aust. 1020 ºC

D 2 aust. 1010 ºC

Tempering Temperature (°C)

Hard

ness (

HR

C)

Tempering Curve

CCT Curve – VF800AT

208HV

224HV

400HV

570HV

806HV

825HV

813HV 661HV

719HV

748HV

684HV781HV

723HV

0,01ºC/s

0,1ºC/s 0,02ºC/s

0,05ºC/s0,15ºC/s

0,5ºC/s

30ºC/s

15ºC/s

5ºC/s

3ºC/s

1ºC/s

0,2ºC/s

0,3ºC/s

-200

0

200

400

600

800

1000

1200

1 10 100 1000 10000 100000

Tempo (s)

T (

ºC)

Ms

Mf

P

FC

Ac1e=907

Ac1b=847

252

Time (s)

Microstructure comparision

AISI D2

VF800 AT

AISI D6

VF800AT has a very refined

microstructure and primary

carbides with better distribution

than other traditional cold work

tool steels

VF800AT – Primary carbides analysis

0

200

400

600

800

1000

1200

1400

0 1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00 9,00 10,00

Energia (KeV)

Inte

ns

idad

e

V

Cr

V

Mo

C

Fe

FeV

0

200

400

600

800

1000

1200

0 1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00 9,00 10,00

Energia (KeV)

Inte

ns

idad

e

Nb

CrVNb

C

Fe

Fe

One of the main reasons of the good combination

of high wear resistance and toughness is the

mixture of Nb-carbides and Cr-carbides in the

VF800AT microstructure.

Wear Resistance

0

0,5

1,0

1,5

2,0

2,5

3,0

AISI M2 VF800AT AISI D2

Sp

ec

ific

am

ou

nt

of

wea

r (m

m/N

. m

m-3

)

Final Load: 61,80NSlide distance: 200mSliding speed: 2,4m/sFriction wheel: SCM420 (86HRB)Sample hardness: 60-61HRC

x105

Main produced sizes

Round bars: diameter ranging from ½”up up 24”

Flat bars: Thickness of 4” and larger

All flat bars and rounds with diameter larger then 3” are produced through

ESR route.

VF800AT x AISI D2

Case Study

Punches applied in the manufacture of automotive steel wheels. Tool life was controlled in

number of produced parts.

Comparison between AISI D2 x VF800AT

The tools produced in VF800AT provided an improved performance exceeding the D2 by 5

times for applications in forming punches and 2.5 times for pre-cut bushings.