Produtos -Metallic Fibers

As requested by PETROBRAS, ENGEMASA nationalized the manufacturing of metallic needles produced by the "Melt-Extrated" process in stainless steels. The needles are mostly used in the refractory materials industry, where they added as a structural reinforcement, both to the siderurgical concrete and petrochemical furnaces.The running principle of the metallic needles in stainless steel consists of being an "anchor" to cracks that occur naturally or by thermal cycle (gradient) that occur naturally in ceramic materials (refractory or concrete), preventing the propagation of cracks and increasing the useful life of the refractory.

In the siderurgical industry the metallic needles in stainless steel are added to refractory concrete for furnace lining and for structural reinforcement in lances for LD converters. The characteristics that the metallic fibers in stainless steel associate to the concretes are structural (providing a "skeleton" to the structure or piece), thermal strength (withstands thermal shocks and high temperatures without oxidizing) and high resistance to corrosion (input increased useful life to structure).

Chemical composition
Alloy
Designation
CHEMICAL COMPOSITION (%)
PROPERTIES
C
Mn
Si
P
S
Cr
NI
Mo
Others
Melting
Range
Thermal
Conduct.
at
540º C
Mod.
of Elast.
at
870º C
Tensile
Strength
at
870º C
Coeff. of
Thermal
Expans.
at
540º C
Oper.
Temp.
Usual
Fiber
Dimens.
(ºC)
(W/m k)
(GPa)
(MPa)
µm/mC
(ºC)
(mm)
  AISI 304
0,08
2,00
1,00
0,045
0,03
18,0
20,0
8,0
10,50
-
-
1400 - 1450
20,9
193
120
18,4
1030
25,4 x 0,51
  AISI 310
0,25
2,00
1,50
0,045
0,03
24,0
26,0
19,0
22,0
-
-
1400 - 1450
20,4
200
149
16,9
1232
25,4 x 0,51
  AISI 330
0,08
2,00
0,75
1,50
0,04
0,03
17,0
20,0
34,0
37,0
-
-
1400 - 1425
21,5
196
193
16,7
1232
25,4 x 0,51
  AISI 430
0,12
1,00
1,00
0,04
0,03
23,0
27,0
-
-
-
1425 - 1510
26,3
200
47
11,4
815
25,4 x 0,51
  AISI 446
0,20
1,50
1,00
0,04
0,03
23,0
27,0
-
-
0,25N
1425 - 1510
24,4
200
53
11,2
1204
25,4 x 0,51
  AISI 297
  GR HT
0,35
0,75
2,00
2,50
0,04
0,04
15,0
19,0
33,0
37,0
0,50
-
1480 - 1530
26,5
83
58
11,4
1093
25,4 x 0,51