303 stainless steel plate

303 Stainless Steel Plate



Product Description

303 Stainless Steel Plate

303 stainless steel plate

Grade 303 stainless steel plate represents the optimum in machinability among the austenitic stainless steels. It is primarily used when production involves extensive machining in automatic screw machines. Machinability Rating (compared to B1212) is approximately 78%.303 is also available as a “Ugima” Improved Machinability grade, with machinability even higher than that of the standard 303.

 

The sulphur addition which is responsible for the improved machining and galling characteristics of Grade 303 lowers its corrosion resistance to below that of Grade 304. As for other austenitic grades the structure gives 303 excellent toughness, although the sulphur in 303 reduces its toughness slightly.Grade 303Se (UNS S30323) has a selenium rather than sulphur addition, improving the hot and cold forming characteristics over those of 303 and providing a smoother machined surface finish. The machinability rate is also slightly reduced. Grade 303Se is not readily available in Australia.

Applications of 303 Stainless Steel Plate:

Typical compositional ranges for grade 303 stainless steels are given in table 1.

Table 1. Composition ranges for 303 grade stainless steel

 

Grade

C

Mn

Si

P

S

Cr

Mo

Ni

Se

303

min.

max.

-

0.15

-

2.00

-

1.00

-

0.20

0.15

-

17.0

19.0

-

8.0

10.0

-

303Se

min.

max.

-

0.15

-

2.00

-

1.00

-

0.20

0.06

-

17.0

19.0

-

8.0

10.0

0.15

min

Typical mechanical properties for grade 303 stainless steels are given in table 2.

Table 2. Mechanical properties of 303 grade stainless steel

Grade

Tensile Strength (MPa)

Yield Strength 0.2% Proof (MPa)

Elongation (% in 50mm)

Hardness

Rockwell B (HR B)

Brinell (HB)

303

-

-

-

-

262 max

Typical physical properties for annealed grade 303 stainless steels are given in table 3.

Table 3. Physical properties of grade 303 stainless steel plate in the annealed condition

Grade

Density (kg/m3)

Elastic Modulus (GPa)

Mean Coefficient of Thermal Expansion (μm/m/°C)

Thermal Conductivity (W/m.K)

Specific Heat 0-100°C (J/kg.K)

Electrical Resistivity (nΩ.m)

0-100°C

0-315°C

0-538°C

at 100°C

at 500°C

303

8027

193

17.3

17.8

18.4

16.3

21.5

500

720

Approximate grade comparisons for 303 stainless steels are given in table 4.

Table 4. Grade specifications for grade 303 stainless steel plate

Grade

UNS No

Old British

Euronorm

Swedish SS

Japanese JIS

BS

En

No

Name

303

S30300

303S31

58M

1.4305

X8CrNiS18-9

2346

SUS 303

303Se

S30323

303S42

-

-

-

-

SUS 303Se

Possible alternative grades to grade 303 stainless steels are given in table 5.

Table 5. Possible alternative grades to 303 grade stainless steel

Grade

Why it might be chosen instead of 303

304

Better corrosion resistance, formability or weldability are needed, at the expense of lower machinability.

316

Higher resistance to pitting and crevice corrosion is required, in chloride environments. A lower machinability can be accepted.

416

Even higher machinability than 303 is needed, and a lower corrosion resistance can be tolerated.

Or hardening by thermal treatment is required, while maintaining a high machinability.