What Is The Difference Between 300 And 400 Series Stainless Steel
the 300 series stainless steels are austenitic stainless steels with non-magnetic properties. They have have 17% to 19% chromium, 8-10% nickel, manganese, carbon, sulfur, phosphorus and silicon in the composition. These are corrosion resistant stainless steels and are one of the most widely used types of steels. The grades vary such as 302, 304 and 316. The 304 is the most used of all stainless steels and the 316 is the second most used of all stainless steels in various applications. The 400 series is ferritic stainless steels with 11% chromium, manganese, sulfur, phosphorus and other elements in smaller quantities. These materials contains little to no nickel in the composition. They have poor corrosion resistance compared to the 300 series but have high abrasion resistance and wear and tear resistance. The grades vary such as 403, 405, 409, 410 and so on.
Since the nickel content is low, the 400 series is cheaper than the 300 series of stainless steels. The 300 series is used in applications that require corrosion resistance where the 400 series is applied in applications that require high wear and tear resistance. However, the 300 series is most used because most of the applications consider corrosion resistance over the wear and tear capacities.
The chromium content in the 400 series provides some level of corrosion resistance but it is poor against steam, flowing water, chlorides, oxidizing agents and reducing agents. However, the 300 series provides better strength and corrosion resistance against most of these corrosive agents. Some particular grades such as the 316 grade have higher corrosion resistance against specific agents such as the chloride ion. So the 300 series of products are used in marine, oil and gas, petroleum, petrochemical, oil and gas and in other applications where the products are prone to corrosion risk. The 400 series is used applications such as transportation, platforms, handrails, automobile parts and other applications where the wear and tear is high but the corrosion resistance is not the primary concern.
The 300 series is good for welding compared to the 400 series. The 400 series can cause deformations and cracking during welding. Both these materials can be welded with most traditional methods, but the 300 series could be welded without causing any damages to the material. The 400 series can crack and is often welded with 304 grade of sheet metal from the 300 series to make sure that there is a more fluid weld puddle and the bridging of gaps can be better performed.
| VALUES COMPARISON CHART | DUPLEX STEEL | SS 304L AND 316L | SS 410 AND 416 |
|---|---|---|---|
| CORROSION RESISTANCE | Excellent | Good | Moderate |
| MACHINABILITY | Excellent | Poor/Gummy – will not hold bright finish | Good |
| WELDABILITY OF STEEL | Excellent | Good | Moderate¹ |
| SOUR SERVICE (SS) ENVIRONMENTS | Excellent | Poor | Acceptable |
| STRENGTH OF STEEL | Excellent | Poor / Not hardenable by heat treatment | Good |
| ANTI-GALLING | Good | Poor / Parts can seize and gall | Moderate / Parts can seize |
| WEAR RESISTANCE | Excellent | Moderate | Good/Further hardening diminishes |
| MAGNETIC | Yes | No | Yes |
| SHOCK RESISTANCE | Excellent | Excellent | Good |
| RETAINED STRESS | Less retained stress | Poor / High degree of memory | Moderate / High degree of memory |
| LONG LENGTHS AVAILABLE | Yes | No | Yes |
| FINISH OPTIONS | TGP Bearing-Fit, RTOS | Centerless TGP, Cold Drawn | Hot Roll, TGP |
| YIELD STRESS (TYP) | 65,000 PSI minimum | 304L = 25,000 PSI 316L = 30,000 PSI |
410 = 90,000 PSI 416 = 110,000 PSI |
| SERVICE TEMPERATURE RANGE | 750°F | 304L = 1100°F 316L = 1400°F |
410 = 1100°F 416 = 1100°F |
| TENSILE STRESS (TYP) | 94,000 PSI minimum | 304L = 70,000 PSI 316L = 75,000 PSI |
410 = 120,000 PSI 416 = 124,000 PSI |
| THERMAL HARDENABILITY | No | No² | Yes |
| 302 | bit higher strength and corrosion resistance is similar to 304 |
| 301 | Known for Better weldability and fatigue strength compared to SS 304 |
| 321 | Addition of titanium alloy |
| 304 | Most popular grade, also known as 18/8 stainless steel, A2, ISO 3506 |
| 316 | ANother most popular grade after 304, also known as marine grade, A4, ISO 3506 |
| 303 | Also known as "A1", ISO 3506 |
| 309 | temperature resistance is good compared to grade 304 |
| 409 | Its one of the cheap grade mainly used in automobile |
| 408 | Contains 8% Nickel. 11% Chromium |
| 416 | Contains additional sulfur |
| 430 | Have excellent formability |
| 440 | Contains additional carbon, comes different grades 440A, 440B, 440C and 440F |
| 410 | less corrosion resistant and Wear resistant grade |
| 420 | Also known as surgical steel, have good polishability |
