430 stainless steel is ferritic steel containing chromium as major alloying elements and belongs to the category of non-hardenable steel. This steel grade provides an excellent combination of corrosion resistance and practical mechanical properties. Common Applications of this steel are Automatic Screw machines, Dishwasher linings, and lashing wires.
430 Stainless Steel Composition
|Cr||14 - 18 %|
430 Steel Properties
|Melting Point||1425 - 1510 C|
|Maximum Service Temperature, Air||815 C|
|Yield Strength||310 MPa|
|Poisson ratio||0.27 - 0.3|
|Elastic Modulus||200 GPa|
|Elongation at Break||0.3|
|Hardness (Rockwell B)||82|
|430 steel||CTE Liner (µm/m - C)|
|Thermal Conductivity (W/m. K)||26.1 /m-K|
|Specific Heat Capacity||0.461 J/g - C|
|430 Steel||Electrical resistivity (ohm - cm)||Magnetic Permeability|
|20 C||6.0E-5||600 - 1100|
430 stainless steel Heat treatment
Ferritic Stainless steel, normally, is non-hardenable. It means their hardness will not increase during quenching. The only heat treatment applicable is annealing. It is carried out by heating at 815oC for 30 minutes and, furnace cool to 600oC and, from there, quick air cooling.
Slow cooling below 600oC results in embrittlement of this grade steel so it is normally avoided.
Elongation at break shared in mechanical properties describes the final length to initial length after breakage after the tensile test. This indicates the ability to resist shape change in a material without fracture and used for indication of the degree of bending of steel.
This steel grade has a large elongation at break i.e. 25% which indicates higher ductility and lower work hardening rate. So, this steel grade can readily be shaped without an increased risk of brittle cracks or fractures. Sub-critical annealing may be used for rigorous cold-working.
430 steel Welding
For welding this grade steel, it should be preheated to 150oC. After welding, post-weld annealing can be used to reduce brittleness in this steel grade. Recommended filler rods for this type of steel are 430, 308L, 309, and 310.
Find fillers for welding of 430 SS on Alibaba.
430 Stainless Steel Machining
430 stainless steel is considered easily machineable as compared to 300 series of Stainless steel. The reason for easy machining is high elastic modulus. High elastic modulus material does not stretch or bend easily, resulting in better machining.
Elastic modulus is a term that describes deformation in the material in response to force applied. If deformation is less than that means the material is less gummy and has a higher elastic modulus. So, in this case, the elastic modulus of 430 steel is 200 GPa which is considered high as compared to 300 series steel’s elastic modulus.
The best way to machine this steel grade is to process it in stain-hardened condition when a material is already stressed. In stressed conditions, deformation will be less and this steel grade will easily break off in pieces. In an annealed state, soften structure will tend to gall resulting in slightly difficulty machining.
This steel grade can resist high-temperature oxidation up to 820oC. However, it will become brittle on cooling. This problem can be alleviated using proper post-annealing.
Grade 430 steel belongs to the class of ferritic steels and all ferritic grades have excellent corrosion resistance (stress-corrosion). They are resistant to several chemicals, organic and nitric acids. Corrosion resistance further levels up if this steel is used in polished condition. In the case of pitting corrosion resistance, it is comparable to 304 steel.
430 Stainless Steel Applications
Steel 430 is used in lots of decorative applications where chances of stress corrosion cracking are high. Common applications are;
- Dish Washer Liners
- Refrigerator Cabinet Panels
- Stove Trim Rings
- Fuel Linings
430 stainless steel is non-hardenable, rich in chromium stainless steel. They possess excellent corrosion and heat resistance along with optimum formability and mechanical properties. They can be used in chemical applications along with fuel linings, fasteners, and many more.
Food grade means still must have high crossing resistance, resistance against stress corrosion cracking, organic and nitric acids. All these qualities are present in 430 steel due to very high chromium content making it one of the best food-grade steel in the market.
430 is the best food-grade material with magnetic characteristics. It has good corrosion resistance with practical sheet bending ability. This steel can be used in the presence of strong acids and also at high temperatures like 800oC.
Annealing of 430 steel is carried out by heating it at 820oC and soaking it there for 15 minutes. After homogenizing, it is slowly cooled up to 600oC and after that quickly air-cooled to avoid embrittlement.
Stainless steel 430 is made of 16% Chromium, 0.1% Carbon, 1% Manganese, 1% silicon and 0.03% sulfur.
430 stainless is ferritic steel while 316 steel is austenitic steel. The ferritic structure is magnetic while the austenitic structure is non-magnetic. Due to the ferritic structure of 430 steel, It is attracted to a magnet.
304 and 430 are different in terms of structure. 304 steel is austenitic while 430 steel is ferritic. Due to this 304 is non-magnetic while 430 is magnetic. Due to higher chromium content in 430 as compared to 304, it can be used in food processing applications.