Introduction of Stainless Steel Castings
Simply put, stainless steel castings are steel that is not easy to rust. In fact, some stainless steels have both rust resistance and acid resistance (corrosion resistance). The rust resistance and corrosion resistance of stainless steel castings are due to the formation of a chromium-rich oxide film (passivation film) on the surface. This rust resistance and corrosion resistance are relative.
Tests have shown that the corrosion resistance of steel in weak media such as the atmosphere and water and oxidizing media such as nitric acid increases with the increase of the chromium content in the steel. When the chromium content reaches a certain percentage, the corrosion resistance of the steel changes suddenly. That is, from easy to rust to not easy to rust, from no corrosion resistance to corrosion resistance.
In many industrial applications, stainless steel can provide satisfactory corrosion resistance. According to the experience of use, the corrosion of stainless steel is mainly manifested in: a serious form of corrosion of stainless steel is localized corrosion (that is, stress corrosion cracking, pitting corrosion, intergranular corrosion, corrosion fatigue and crevice corrosion). The failure cases caused by this local corrosion accounted for almost half of the failure cases. In fact, many failure accidents can be avoided through reasonable selection of materials.
Types and Grades of Stainless Steel Castings
- 1. Austenitic Stainless Steel Castings
- 2. Ferritic Stainless Steel Castings
- 3. Martensitic Stainless Steel Castings
- 4. Duplex Stainless Steel Castings
- 5. Precipitation Hardening Stainless Steel Castings
After years of research and development, stainless steel has been classified into many categories. Among them, according to the different matrix structure of stainless steel materials, it is mainly divided into:
1. Austenitic Stainless Steel Castings
Austenitic stainless steel is stainless steel material with a stable austenitic structure inside. In addition to containing 18% chromium and about 8% nickel, it also contains a small amount of molybdenum, titanium, nitrogen and other elements. This kind of stainless steel material is a product with good comprehensive performance and can withstand the corrosion of multiple media. Moreover, the toughness and ductility of austenitic stainless steel are better, and at the same time, its free cutting performance is also very good. At present, austenitic stainless steel materials are widely used in various industries.
At the same time, we can talk about the 304 and 304L, 316 and 316L, where the "L" stands for low carbon, making each grade of material softer but more resistant to corrosion. Generally, casting products used at the seaside or at high frequency at sea will have a longer life with 316L, even though 316 has been known for its excellent corrosion resistance.
Austenitic stainless steel is the most common material used in our silica sol investment casting plant, and basically half of the output is austenitic stainless steel. Regardless of the American standard, such as SUS304, the German standard, such as 1.4301, 1.4308, 1.4408, and the Japanese standard, such as SCS13, except for the slight difference in the range of individual elements, there is little difference in general chemical composition. We are committed to providing the production of non-standard parts, strictly in accordance with the material standards provided by the customer, to ensure that every element can meet the standard requirements, so that customers can ensure the integrity of the function and the safety of use during the long-term use of the product.
| Austenitic Stainless Steel Casting Grades | |||||
| Grades | C | Mn | Cr | Ni | Mo |
|
CF-16Fa (303) |
0.16 Max | 1.5 Max | 18.0 -21.0 | 9.0-12.0 | 0.40-0.80 |
| CF-8-304 | 0.08 Max | 1.5 Max | 18.0-21.0 | 8.0-11.0 | |
| CF-3(304L) | 0.03 Max | 1.5 Max | 17.0-21.0 | 8.0-12.0 | |
| CF-8M-316 | 0.08 Max | 1.5 Max | 18.0-21.0 | 9.0-12.0 | 2.0-3.0 |
| CF-3M(316L) | 0.03 Max | 1.5 Max | 17.0-21.0 | 9.0-13.0 | 2.0-3.0 |
| CF-8C-347 | 0.08 Max | 1.5 Max | 18.0-21.0 | 9.0-12.0 | |
| CG-8M-317 | 0.08 Max | 1.5 Max | 18.0-21.0 | 9.0-13.0 | 3.0-4.0 |
2. Ferritic Stainless Steel Castings
Ferritic stainless steel is the most common type of stainless steel material. It is a kind of stainless steel whose main structure is ferritic in use. The chromium content of this kind of stainless steel is between 11% and 30%. In addition, it also contains a small amount of elements such as molybdenum, titanium and niobium. In addition to good corrosion resistance, ferritic stainless steel is characterized by good oxidation resistance, excellent stress resistance, and it also has good thermal conductivity and a very small expansion coefficient. However, the plasticity of ferritic stainless steel is poor, therefore, this kind of stainless steel material is mainly used to make corrosion-resistant parts.
409 stainless steel is a relatively cheap stainless steel, usually used as a car exhaust pipe.
| Ferritic Stainless Steel Casting Grades | ||||||
| Grades | C | Mn | Si | Cr | Ni | Mo |
| Max | Max | Max | Min-Max | Max | Max | |
| 409 | 0.16 | 1.5 | 2 | 10.5-11.75 | 0.5 | |
| /Nb | ||||||
| 442 | 0.3 | 1 | 1.5 | 18.0-22.0 | 2 | |
| (CB-30) | ||||||
| 446 | 0.5 | 1 | 1.5 | 26.0-30.0 | 4 | |
| (CC-50) | ||||||
3. Martensitic Stainless Steel Castings
Martensitic stainless steel is a hardenable stainless steel material. The biggest feature of this kind of stainless steel material is that the mechanical properties of this kind of stainless steel material can be changed by heat treatment. At present, this kind of stainless steel material is mainly used in the processing of steam turbine blades, surgical instruments and other products.
This conventional stainless steel material has been widely used in automobile power and exhaust systems. Especially in recent years, Japan has increased the use of stainless steel material. Its performance is close to that of austenitic stainless steel. The price is more competitive than austenitic stainless steel.
However, most domestic foundries do not have enough strength and experience to make stainless iron materials with similar austenitic properties. The most obvious defect is that the castings will crack at high temperatures, which is a major taboo in the industry. At the same time, stainless iron cannot be simply pickled to achieve bright white, generally gray-black. Therefore, in this area, domestic foundry factories and auto parts factories need to invest energy and financial resources to study carefully.
| Martensitic Stainless Steel Casting Grades | ||||||
| Grades | C | Mn | Si | Cr | Ni | Mo |
| Min-Max | Max | Min-Max | Min-Max | Min-Max | Min-Max | |
| 410 | 0.05-0.15 | 1 | 1.5 Max | 11.5-14.0 | 1.0 Max | 0.5 Max |
| 416 | 0.15 Max | 1.25 | 1.50 Max | 11.5-14.0 | 0.50 Max | 0.50 Max |
| 420 | 0.15 Max | 1 | 1.0 Max | 12.0-14.0 | ||
| 15-5 PH | 0.05 Max | 0.6 | 0.50-1.00 | 14.00-15.50 | 4.20-5.00 | |
| 17-4 PH | 0.06 Max | 0.7 | 0.50-1.00 | 15.5-16.7 | 3.60-4.60 | |
4. Duplex Stainless Steel Castings
Duplex stainless steel is stainless steel in which the ferrite and austenite phases in the solid solution structure each account for about 50%. It not only has good toughness, high strength and excellent resistance to chloride corrosion, but also resistance to pitting corrosion and intergranular corrosion. Corrosion, especially stress corrosion resistance in chloride environment.
The cost of duplex stainless steel is relatively the highest, generally 1.5 to 2.5 times the price of austenitic stainless steel. But its performance is also excellent. Usually used in the chemical industry, it needs to withstand the dual pressure of high corrosiveness and high temperature, it can still have a better life performance.
As a stainless steel foundry, there are still some concerns when encountering the customized business of duplex stainless steel. The main reason is that the business volume of duplex stainless steel in the market is small throughout the year. As a factory, it is really difficult to balance the interests of customers and the minimum order cost.
| Duplex Stainless Steel Casting Grades | ||||||
| Grades | C | Mn | Si | Cr | Ni | Mo |
| Max | Max | Max | Min-Max | Min-Max | Min-Max | |
|
ASTM A890 Grade 1A (CD4MCu) |
0.04 | 1 | 1 | 24.5-26.5 | 4.75-6.00 | 1.75-2.25 |
|
ASTM A890 Grade 4A (CD3MN) |
0.03 | 1.5 | 1 | 21.0-23.0 | 4.5- 6.5 | 2.5-3.5 |
5. Precipitation Hardening Stainless Steel Castings
Precipitation hardening stainless steels have corrosion resistance comparable to austenitic varieties, but can be precipitation hardened to even higher strengths than other martensitic grades.
The 17-4PH material is an American grade, a martensitic precipitation hardening stainless steel, which is equivalent to a Chinese grade: 0Cr17Ni4Cu4Nb.
17-4PH alloy is a precipitation, hardening, martensitic stainless steel composed of copper and niobium/columb.
This grade has high strength, hardness and corrosion resistance.
After heat treatment, the mechanical properties of the product are more perfect, and can reach a compressive strength of up to 1100-1300 mpa (160-190 ksi). It has good corrosion resistance to the atmosphere and diluted acid or salt. Its corrosion resistance is the same as 304 and 430.
| Precipitation Hardening Stainless Steel Casting Grades | |||||||
| Grades | C | Mn | P | S | Si | Cr | Ni |
| 17-4 PH | 0.07 max. | 1.0 max. | 0.04 max. | 0.03 max. | 1.0 max. | 15.0–17.5 | 3.0–5.0 |
| A286 | 0.08 max. | 2.0 max | 0.02 max. | 0.025 max. | 1.0 max. | 13.5-16 | 24-27 |
Key Considerations for Selecting Stainless Steel Grades
When selecting a stainless steel grade for your project, several factors need careful consideration.
Corrosion Resistance
The corrosion resistance of stainless steel is a crucial aspect to evaluate. Different grades possess unique corrosion-resistant properties, so it is essential to identify the level of protection required for your specific environment or application. Consider the exposure to corrosive elements such as moisture, chemicals, or salt, and choose a stainless steel grade accordingly.
Mechanical Properties
Examining the mechanical properties of stainless steel grades is another critical factor. These properties encompass factors such as tensile strength, yield strength, hardness, and ductility, which directly impact the material's performance under various conditions. Determine the specific mechanical requirements of your project and select a grade that aligns with those prerequisites.
Temperature Resistance
In applications involving extreme heat or cold, temperature resistance becomes pivotal. Stainless steel grades exhibit varying degrees of resistance to elevated temperatures, thermal cycling, and cryogenic conditions. Assess the intended operating temperature range and ensure that the chosen grade can withstand the anticipated thermal stresses.
Cost Considerations
While technical requirements are important, it is also crucial to evaluate the associated costs of the desired stainless steel grade. Different grades come with varying price points due to their specific alloy composition and performance characteristics. Strive for a balance between performance and cost-effectiveness to maximize the value derived from your stainless steel selection.
The Best Stainless Steel Casting Factory Around You
Best Stainless Steel Castings Manufacturer in China
We are a manufacturer of stainless steel castings in China. Can design and produce various types of stainless steel castings for you.
For more than 20 years, Besser has specialized in the investment casting process. We can assure you that high-quality castings are produced in an efficient manner. Provide customers with truly professional stainless steel casting solutions.
At the same time, Besser uses the German high-end brand SPECTRO spectrometer to control the chemical composition of each furnace of molten steel to ensure that the correct composition of molten steel is cast into customers' products.
The picture below is a photo of the spectrometer
We Provide Services for Stainless Steel Castings
- High-precision machining
- Polished galvanized, nickel-plated, electroplated, chrome-plated
- Anodizing, phosphating, acid treatment, polishing
- Broaching, milling, drilling, tapping
- Surface grinding, sandblasting, powder coating
- Heat treatment
Why Choose Our Stainless Steel Castings
You get more professional customized services than our competitors provide.
- Unlike other suppliers, we have over 10 years of global sales and service experience in overseas markets.
- At present, it has launched trade with more than 10 countries around the world and has cooperated with many global top 500 companies
- Our prices are more affordable than other casting manufacturers.
The above is the introduction of the various categories of stainless steel castings. If you want to know more information, please contact us.