İşlenebilirliği: Uygun takım ve soğutma ile oldukça iyi.
Soğuk şekil verilebilme: Zayıf.
Kaynak edilmesi : Çok zor.
Korozyon Dayanımı: Zayıf asitlere dayanımı iyidir. Özellikle oksitleyici ortamda klorüre karşı hassastır.
Sıcaklık Dayanımı: 700 derece sıcaklığa kadar paslanma görülmez.
Kullanım Alanları: Yüksek dayanım ve aşınmaya karşı mukavemet gereken yerlerde kullanılır, kırılgandır.
Bıçak ve tıbbi aletler, kalıp parçaları, fren diskleri.
Alternatif Kaliteler: AISI 420A/B/C.
Satılan Formları: Çubuk, Sac.
The compositional ranges of grade 420 stainless steels are given in following table:
Table 1 - Compositional ranges of grade 420 stainless steels
Grade |
C |
Mn |
Si |
P |
S |
Cr |
|
420 |
min. max. |
0.15 - |
- 1 |
- 1 |
- 0.040 |
- 0.03 |
12.0 14.0 |
The key mechanical properties of grade 420 stainless steels are tabulated below:
Table 2 - Mechanical properties of grade 420 stainless steels
Tempering Temperature (°C) |
Tensile Strength (MPa) |
Yield Strength |
Elongation (% in 50mm) |
Hardness Brinell (HB) |
Impact Charpy V (J) |
Annealed * |
655 |
345 |
25 |
241 max |
- |
204 |
1600 |
1360 |
12 |
444 |
20 |
316 |
1580 |
1365 |
14 |
444 |
19 |
427 |
1620 |
1420 |
10 |
461 |
# |
538 |
1305 |
1095 |
15 |
375 |
# |
593 |
1035 |
810 |
18 |
302 |
22 |
650 |
895 |
680 |
20 |
262 |
42 |
* Annealed tensile properties are typical for Condition A of ASTM A276; annealed hardness is the specified maximum. |
The table below provides the physical properties of grade 420 stainless steels in their annealed state:
Table 3 - Physical properties of annealed grade 420 stainless steels
Grade |
Density (kg/m3) |
Elastic Modulus (GPa) |
Mean Coefficient of Thermal Expansion |
Thermal Conductivity |
Specific Heat 0-100°C |
Electrical Resistivity (nΩ.m) |
|||
0-100°C |
0-315°C |
0-538°C |
at 100°C |
at 500°C |
|||||
420 |
7800 |
200 |
10.3 |
10.8 |
11.7 |
24.9 |
- |
460 |
550 |
The proximate grade specifications of 420 stainless steels are given in the table below: (These specifications are for functionally similar materials. Original specifications can be referred to for exact equivalents.)
Table 4 - Grade comparisons of grade 420 stainless steels
Grade |
UNS No |
Old British |
Euronorm |
Swedish SS |
Japanese JIS |
||
BS |
En |
No |
Name |
||||
420 |
S42000 |
420S37 |
56C |
1.4021 |
X20Cr13 |
2303 |
SUS 420J1 |
The following table gives the suitable alternative grades to grade 420 stainless steels:
Table 5 - Possible alternative grades of grade 420 stainless steels
Grade |
Reasons for choosing grade 420 |
410 |
Only a lower hardened strength is needed. |
416 |
High machinability is required, and the lower hardened strength and lower corrosion resistance of 416 is acceptable. |
440C |
A higher hardened strength or hardness than can be obtained from 420 is needed. |
"Specials" |
Variations of 420 are available to special order. These offer higher hardness, corrosion resistance and machinability for particular applications. |