Introduction to the use of 200, 300, 400 series stainless steel grades
200 series stainless steel
POSZPHT1
The 200 series austenitic stainless steel was developed by replacing Ni elements with Mn and N elements. This steel has good corrosion resistance and hot and cold processing properties, and it can replace 304 products used in indoor, inland cities and outdoor environments with low corrosiveness.
(1) Features and practical uses
| Steel type | POSZPHT1 |
| Characteristics | After solution treatment, it has high strength, toughness, and wear resistance; economical, low Ni composition ensures the cost advantage. |
| Application | Decorative tubes, industrial tubes, and some shallow-drawn products. Such as shallow processing pots, indoor staircase handrails, elevators, mirror surfaces, brushed surfaces, and other surface-processed products. |
(2) Main chemical composition: (unit: wt%)
| Grade | C | Mn | Cr | Ni | Cu | Other |
| POSZPHT1 | ≤0.10 | 7.0-10.5 | 13.0-17.0 | 0.5-3.0 | 1.0-3.0 | N：0.1-0.3 |
(3) Mechanical properties
| Grade | YS（Mpa） | TS（Mpa） | EL（%） | HV | Remark |
| POSZPHT1 | 426 | 880 | 52 | 224 | 1.0t |
| 304 | 285 | 710 | 58 | 165 | 1.0t |
(4) Use cases
POSZPHT4
The 200 series austenitic stainless steel was developed by replacing Ni elements with Mn and N elements. This steel has good corrosion resistance and hot and cold processing properties, and it can replace 304 products used in indoor, inland cities and outdoor environments with low corrosiveness.
(1) Features and practical uses
| Grade | POSZPHT4 |
| Characteristics | On the basis of POSZPHT1, increase the content of Cr and Ni, and improve the workability and corrosion resistance. |
| Application | Decorative tubes, industrial tubes, and some shallow-drawn products. Such as shallow processing pots, indoor staircase handrails, elevators, mirror surfaces, brushed surfaces, and other surface-processed products. |
(2) Main chemical composition: (unit: wt%)
| Specification | C | Mn | Cr | Ni | Cu | Other |
| POSZPHT4 | ≤0.08 | 5.5-7.2 | 16.0-17.7 | 3.5-4.4 | ≤2.0 | N： 0.06-0.18 |
(3) Mechanical properties
| Specification | YS（Mpa） | TS（Mpa） | EL（%） | HV | Remark |
| POSZPHT4 | 370 | 840 | 58 | 200 | 1.0t |
| 304 | 285 | 710 | 58 | 165 | 1.0t |
(4) Use cases
300 series stainless steel
301(L)
Contrast 304 contains low Ni, Cr, and high N components. According to the high strength that can be achieved by rough rolling, compared to Steel, Al has excellent high-temperature strength, fatigue strength, and corrosion resistance. It is used in trams to achieve lightweight and excellent stability. Performance and economy (301L)
Features and practical uses:
| Grade | 301(L) |
| Characteristics | –Compared with 301, excellent corrosion resistance |
| Application | –Insulation lunch box, thermos bottle, SINK BOWL, gas, BURNER parts for trams, internal and external installation of rail vehicles |
Chemical composition: (unit: wt%)
| Specification | C | Si | Mn | P | S | Cr | Ni | Other |
| TYPE 301 | ≤0.15 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | 16.0～18.0 | 6.0～8.0 | |
| TYPE 301L | ≤0.030 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | 18.0～20.0 | 8.0～10.5 | N≤0.02 |
Mechanical behavior:
| Specification | YS（Mpa） | TS（Mpa） | EL（%） | Hv |
| TYPE 301 | ≥205 | ≥520 | ≥40 | ≤218 |
| TYPE 301L | ≥215 | ≥550 | ≥45 | ≤218 |
Use case:
304(L)
As the basic steel of the AUSTENITE series, it has excellent corrosion resistance, heat resistance, low-temperature strength, and mechanical properties. It does not harden after heat treatment and has almost no magnetism.
Features and practical uses:
| Difference | 304 | 304L |
| Characteristics | –Austenitic basic steel, the most widely used; –Excellent corrosion resistance and heat resistance; –Excellent low-temperature strength and mechanical properties; –Single-phase austenite structure, no heat treatment hardening phenomenon | –Compared with 304, excellent corrosion resistance |
| Application | –1-2 categories of tableware, exterior materials, building materials, auto parts, –Medical equipment, chemistry, food technology, fiber industry, –Ship parts | – Equipment in the chemical, coal, and petroleum industries that require high resistance to intergranular corrosion, –Construction materials, heat-resistant parts, and parts that are difficult to heat treat |
Chemical composition: (unit: wt%)
| Specification | C | Si | Mn | P | S | Cr | Ni |
| TYPE 304 | ≤0.08 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | ≤18.0-20.0 | ≤8.0-10.5 |
| TYPE 304L | ≤0.030 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | ≤18.0-20.0 | ≤8.0-10.5 |
Mechanical behavior:
| Specification | YS（Mpa） | TS（Mpa） | EL（%） | Hv |
| TYPE 304 | ≥205 | ≥520 | ≥40 | ≤200 |
| TYPE 304L | ≥175 | ≥480 | ≥40 | ≤200 |
Use case:
304J1
Compared to 304, it ensures excellent moldability (composite moldability, deep processing, excellent processing lag performance, etc.), and excellent aging resistance to cracking
Features and practical uses:
| Grade | 304J1 |
| Characteristics | –Excellent formability and aging crack resistance |
| Application | –Insulation lunch box, thermos bottle, SINK BOWL, gas, BURNER parts |
Chemical composition: (unit: wt%)
| Specification | C | Si | Mn | P | S | Cr | Ni | Other |
| TYPE 304J1 | ≤0.08 | ≤1.70 | ≤3.00 | ≤0.045 | ≤0.030 | 15.0～18.0 | 6.0～9.0 | Cu：1～3 |
Mechanical characteristics:
| Specification | YS（Mpa） | TS（Mpa） | EL（%） | Hv |
| TYPE SUS304J1 | ≥155 | ≥450 | ≥40 | ≤200 |
Formability:
| Distinguish | Thickness(mm) | Er(mm) | LDR | CCV | Aging crack limit |
| TYPE 304J1 | 0.6 | 13.2 | 2.14 | 26.3 | 3.3 |
| TYPE 304 | — | 12.8 | 1.98 | 27.0 | 2.6 |
Use case:
321
The carbon stabilizing element Ti is added to the 304 steel grade to suppress the sharpening of the grain boundary. It was developed for the purpose of using in the sharpening range (450 ℃ ~ 850 ℃). After adding Ti, the defect (Ti-streak) is more common in the steel grade.
Features and practical uses:
| Grade | 321 |
| Characteristics | –Use in the sharpening range (450 ℃-850℃) |
| Application | –Boiler heat exchangers, pipes, expansion joints, and other welding parts/equipment that cannot be heat treated after assembly |
Chemical composition: (unit: wt%)
| Specification | C | Si | Mn | P | S | Cr | Ni | Other |
| TYPE 321 | ≤0.08 | ≤1.00 | ≤2.00 | ≤0.045 | ≤0.030 | 17.00～9.00 | 9.00～13.00 | Ti： ≥ 5 × C% |
Mechanical behavior:
| Specification | YS（ Mpa ） | TS（ Mpa ） | EL（%） | Hv |
| TYPE 321 | ≥205 | ≥520 | ≥40 | ≤200 |
Use case:
304N
It is made by adding 0.1%~0.25% nitrogen to 304 steel. Due to the addition of nitrogen, the strength of the steel is increased, but the plasticity is not reduced, so the thickness of the parts can be reduced. At the same time, the corrosion resistance of steel has also been improved.
Features and practical uses:
| Grade | 304N |
| Characteristics | –S is reduced and N is added to increase the strength; the addition of high N has excellent corrosion resistance |
| Application | –Construction materials, street lights, water pipes, cooling pipes for power plants |
Chemical composition: (unit: wt%)
| Specification | C | Si | Mn | Ni | Cr |
| TYPE 304N | ≤0.050 | ≤0.75 | ≤2.00 | 8.0～10.5 | 18.0～20.0 |
Mechanical behavior:
| Specification | YS（Mpa） | TS（Mpa） | EL（%） | Hv | Remark |
| TYPE 304N | 355 | 697 | 49 | 183 | Cold Rolled 1.5t |
Use case:
300SCC
The addition of Si, Cu, and W to 304 steel greatly improves the stress corrosion resistance and pitting corrosion resistance of the steel compared with 304, while the plasticity is not reduced, and its performance is basically equivalent to that of 316L. Therefore, it can replace 316L in environments such as heat exchangers and hot water boilers.
Features and practical uses:
| Grade | 300SCC |
| Characteristics | –SCC resistance compared to 304 is more than 2 times; pitting corrosion potential compared to 304 is more than 1.3 times |
| Application | –Heat exchanger, boiler |
Chemical composition: (unit: wt%)
| Specification | C | Si | Ni | Cr | Cu |
| TYPE POS300SCC | ≤0.070 | 1.5 | 8.5 | 18.5 | ≤2.0 |
Mechanical behavior:
| Specification | YS（Mpa） | TS（Mpa） | EL（%） | Hv | Remark |
| TYPE POS300SCC | 310 | 650 | 55 | 164 | Cold Rolled 0.6t |
Use case:
