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Stainless Steel Castings
Stainless steel castings, also known as stainless steel investment casting. Typically use the lost wax investment casting process. By pouring melted liquid stainless steel into molds for solidification, then get a solid stainless steel component in the desired shape.
Advantages of Stainless Steel Castings,The Benefits
•Sizes: From 1 in to 600 mm
•Weights: a few grams to more than 100 kgs
•Reliable process controls and repeatability
•Design and casting versatility
•Efficient production
•Affordable tooling
•Material variety
•Excellent corrosion resistance.
•Flexible design
•Tight tolerances
•Good Surface: very smooth finish
Here, we have a full article to introduce the Advantages and disadvantages of Stainless Steel Casting. Kindly view it
Applications of Stainless Steel Casting
Stainless steel casting has the properties of steel and corrosion resistance. Like other cast steel alloys, stainless steel is a widely material used for casting production. If metal castings need corrosion resistance and high strength, stainless steel casting is an ideal choice.
The stainless steel investment casting components are widely used in industries of petrochemical, aerospace, automotive, medical, food, and dairy. Below are parts of stainless steel casting:
• Arms • Handles • Marine equipment • Medical devices• Valve bodies• Pumps• Housings• Gears• Bushings• Brackets
Food Machinery
Almost all food processing equipment is made in stainless steel because of its rust-prevention capability. Such food processing equipment is normally assembled by many stainless steel components. There are several processes to produce these stainless steel components. Such as casting, forging, welding, and machining from the plate. Among these processes, investment casting is the most flexible manufacturing process to produce complex shaped components for food machinery. So stainless steel casting is widely used for food machinery applications!
Typical food machinery components made in the stainless steel casting process: metal grinder components, and coffee machine components.
Valve Casting & Pump Casting Components
Stainless steel casting is the most used process for valve Casting and pump Casting components. The valve and pump components design is complicated. And they also need durable enough for severe service applications Stainless steel casting is able to produce any complex shape and good features for them.
So stainless steel casting is a cost-efficient way and a popular selection for pump and valve applications.
Common valve casting and pump casting components are made from stainless steel casting. valve body, valve disc, valve bonnet, valve gland, pump body, pump impeller.
Marine Application
Stainless steel casting is widely used in marine applications. Seawater environments need parts that have high resistance to heat, abrasion, and corrosion. Stainless steel casting can meet its request well.
Hengke Casting foundry stainless steel alloy casting used marine components. We use the mirror-finish process to get the maximum corrosion and abrasion resistance.
New marine-grade stainless steel investment castings for marine applications could be supplied electro-polished and machined by our company. If you choose marine grade our stainless steel casting. You can save 30% more on costs.
Pipe Fittings
Pipe Fittings are components used for connecting, terminating, and controlling flow. They can change the direction of piping in many different industries.
For pipe fittings, considering the application, 316 stainless steel has higher strength and more corrosion resistance than stainless steel 304. Stainless steel casting is the most cost-effective method for small-volume production.
The typical stainless steel cast fittings are elbow, tee, bushing, and close nipple. Our machining capability can meet any machining demand like threads.
Medical Equipment
Stainless steel casting has tight tolerances and dimensional precision. It can create customized casting parts that meet the requirements of the medical application. JC Casting is able to produce a wide range of components for medical instrument manufacturers.
We work with many stainless steel materials. Such as stainless steel 304(L), stainless steel 316(L) and more.
Stainless steel cast parts we manufacture for medical OEMs are included in: dental tools, surgical tools, Implantable components, operating tables & other operating room equipment, X-ray equipment, stretchers, wheelchairs products, stabilizing devices.
Another Applications of Stainless Steel Castings are Construction casting. Sculpture parts, Bathroom & Toilet fittings, Door & Windows.
The grade for Stainless Steel Casting
Hengke Metal Casting has experience pouring a wide variety of stainless steel investment casts. Here, we listed the most common stainless steel grade alloys we have poured below. If you need we can provide the Specific material chemistry and mechanical specifications.
300 Series Stainless Steel Casting Alloys
Austenitic 300 series stainless steel is a nonmagnetic chromium-nickel alloy. These stainless steel casting alloys are known for their excellent corrosion resistance. but they cannot gain strength through heat treatment. SS 304L and SS 316L alloys also resist corrosion caused by welding and other high-temperature finishing processes. 300 series alloys are commonly used to invest cast piping and housings for industries. Including medical, marine, food and dairy. We provide a range of 300 series stainless steel casting alloys including:
· 302
· 303
· 304
· 304-L
· 310
· 312
· 316
· 316-L
· 319
· 330
· 347
· BS-3146
· Nitronic 50
400 Series Stainless Steel Casting Alloys
Martensitic 400 series stainless steel is a chromium-magnesium alloy. It provides high strength and machinability. This type of stainless steel is magnetic. It can be hardened through quench and tempering to produce high strength. 400 series is frequently used for investment casting machine parts and valves for automotive and agriculture applications. We offer the following alloys:
· 410
· 416
· 418
· 420C
· 430
· 436
· 440A
· 440C
Precipitation Hardening Stainless Steel Castings Alloys
Precipitation hardening alloys provide high strength and corrosion resistance. They are magnetic and can be heat treated and aged to achieve the strength properties of martensitic steels while maintaining corrosion resistance. Precipitation hardening investment casting alloys are widely used by the military and in aerospace and petrochemical applications. We provide PH stainless steel castings using the following alloys:
· PH 15-5
· PH 17-4
· CD4MCu (25-5)
Common Cast Stainless Steel Grades and typical usages
| Common Grade | Features | Applications |
| SS 304 | Austenitic stainless steel with Ni content of more than 8%. Food-grade alloy can be used to cast stainless steel components for both household and commercial applications. It is the most widely used stainless steel casting material. | The food industry, chemical industry, mechanical equipment, pipe industry, automotive industry, Housings, medical, watering, mining, and petrochemical. |
| SS 316 | SS316 is the second most common austenite steel. It is used mainly to increase resistance to corrosion. The Ni content is more than 10%. It has better corrosion resistance than 304 stainless steel castings. 316 stainless steel castings are better suited for the marine environment with harsh air conditions or chemical materials. | Fire fighting, auto parts, marine hardware, chemical, pipeline, construction, decoration, food industry, etc Housings, gears, plates automotive, food & dairy, and petrochemical environments. |
| SS 304L / 316L | The mechanical properties are close to those of ss 304 and 316 materials. “L” represents lower carbon content. The material is more ductile. has good welding performance, and has more reliable corrosion resistance. The price is higher than that of materials of the same grade. | Food, chemical, medical, plumbing, medical, petrochemical |
| SS 410 / 416 | Series 400 belongs to martensitic stainless steel. High strength, good processing performance, and high heat treatment hardness, and does not contain Ni, so the corrosion resistance is weak. They will tend to break rather than bend under intense pressure. | Automotive parts, food & dairy, machine tools, knives, Housings, bushings, handles, brackets |
| PH 17-4 | Most common precipitation-hardening martensitic stainless steel. Its content is about 17% chromium and 4% nickel. good corrosion resistance. 17-4 is the strongest of the stainless steel family. Usually used for products and components that are not prone to deformation. | Military, medical, mechanical components, machine tools, turbine blades,ods, pins, links, arms. |
| 2205 Duplex | Duplex stainless steel 2205 is composite stainless steel consisting of 22% chromium, 2.5% molybdenum, 4.5% nickel-nitrogen. Used for its good mechanical properties and excellent corrosion resistance properties. | Sporting, pump & valve industry. |
Chemical Compositions
| Grades | C | Si | Mn | S | P | Cr | Ni | Mo |
| 304 | ≤0.08 | ≤1.00 | ≤2.00 | ≤0.03 | ≤0.045 | 18 ~ 20 | 8 ~ 11 | – |
| 304L | ≤0.03 | ≤1.00 | ≤2.00 | ≤0.03 | ≤0.035 | 18 ~ 20 | 8 ~ 12 | – |
| 316 | ≤0.08 | ≤1.00 | ≤2.00 | ≤0.03 | ≤0.045 | 16 ~ 18 | 10 ~ 14 | 2 ~ 3 |
| 316L | ≤0.03 | ≤1.00 | ≤2.00 | ≤0.03 | ≤0.045 | 16 ~ 18 | 10 ~ 14 | 2 ~ 3 |
| 410 | ≤0.03 | ≤1.00 | ≤1.00 | ≤0.03 | ≤0.040 | 11 ~ 13.5 | ≤0.6 | – |
| 416 | ≤0.15 | ≤1.00 | ≤1.25 | ≤0.15 | ≤0.060 | 12 ~ 14 | ≤0.6 | – |
| 17-4 ph | ≤0.07 | ≤1.00 | ≤1.00 | ≤0.03 | ≤0.040 | 15.5 ~ 17.5 | 3 ~ 5 | – |
| 2205 | ≤0.03 | ≤1.00 | ≤2.00 | ≤0.03 | ≤0.040 | 21 ~ 24 | 4.5 ~ 6.5 | 2.5 ~ 3.5 |
Stainless Steel Investment Casting Process
1. Make Wax Model
Once the mold is finished, inject wax material into the mold cavity. We get a wax model from the mold after cooling. 2. Repair the wax model
2. Repairing wax model
Repair some appearance defects of wax models. Such as slot, wax injection nozzle, flow pattern.
3. Assembly
After inspecting wax models, weld them to the casting system one by one to form an assembly. It looks like a tree.
4. Shell Making
The shell-making process is a whole silica sol process. It is to dip the assembly into a good colloidal silica coating. sprinkle with fire-resistant sand. dry and hardened shell under certain temperatures. Thus forming a dense refractory coating surface outside the surface of wax models.
Then repeat steps 5-6 times. Finally form a certain strength and refractoriness of silica sol shell.
5. Dewaxing
Dewaxing is a process in which the wax inside the shell is melted by high-temperature steam. Then drain out the melted wax. To get a cavity that can be poured into the mold.
6. Pouring
Melted stainless steel ingots into liquid status under a certain high temperature. Then pour the liquid into the shell and cool at room temperature.
Shell Knocking After solidification, knock out the Shell and clean sand.
7. Cutting, Grinding
Cut the stainless steel casting blanks from the assembly one by one. Remove the sprue gate by grinding machine. Smooth the surface by various surface finishes. Such as shot blasting, sandblasting, electropolishing, and mirror polishing.
8. Inspection
After finishing production, inspection is also an indispensable process before delivery. The stainless steel castings inspection includes dimensional inspection, defects inspection and material inspection. Only qualified products can be shipped to customers.
Post Treatments of Stainless Steel Castings
After Stainless Steel Casting is finished, it will be deep processing. That is the Post Treatment of Stainless Steel Casting. In Hengke Metal, our main Post Treatments include:
- Heat Treatment: Solution Treatment
- Post Machining
- Surface Finish
Heat Treatment: Solution Treatment
Heat Treatment: Solution TreatmentSolution treatment is a kind of heat-treatment process.
In heating processing, stainless steel castings are heated to a high temperature and maintained at a constant temperature in the single-phase zone.
So that the excess phase is fully dissolved into the solid solution. Then cooled rapidly. Finally, we get the su-saturated solid solution.
Unlike heat treatment for other steel investment castings, solution treatment is the only heat treatment method for the stainless steel investment casting process.
The purpose of solution treatment is mainly used to eliminate internal stress. And improve the stainless steel components’ mechanical properties. (e.g. corrosion resistance, ductility, or hardness). It can make the post-machining easier.
PS:
Before stainless steel castings solution treatment operation, casting blank surface cleaning is necessary. Such as removing oils, grease, and other types of residue. Because during stainless steel casting heat treatment, The surface leftover may occur degrading the corrosion resistance or other properties of the products.
Post Machining
Investment casting is the primary method for stainless steel parts production. It can create near-net shape products. even without secondary machining. But it does not mean machining can be saved for all the stainless steel cast products.
when there is a closer tolerance and surface finish requirement that casting can not reach. Post Machining will have to be used. We can remove excess material by grinding, milling, and drilling. We also have our own CNC Center. CNC machining is the most precise machining process. But the cost is high.
After machining, quality Inspection is also very critical. we use manual inspection equipment and gages as well as the latest in coordinate measuring machine (CMM) technology to measure and record all the dimensions. This ensures our customers always get the quality they want.
Surface Treatments
For stainless steel casting, there are several surface treatment methods to improve its appearance qualtiy. It includes shot blasting, sandblasting, electropolishing, mirror polishing, and powder coating.
Shot Blasting
The most common and Low-cost surface finish method. It can remove casting surface mill scales, and burrs. It is the process to smooth stainless steel castings by grinding of small steel balls in a shot-blasting machine.
Sand Blasting
The process of cleaning the stainless steel casting surface by the impact of high-speed sand flow. The surface is more smooth than that of sand casting. But the cost is higher.
Electropolishing
Take stainless steel castings as the anode for electrolysis. It is used in an appropriate electrolyte to remove its rough surface. It can improve its surface smoothness. The surface becomes a bit bright after electropolishing.
Mirror Polishing
It is a manual polishing process operated with a grinding wheel. After finishing, the casting surface will look very shiny like a mirror. This treatment is the most time costing surface finish method. Mirror Polishing is only suitable for outside areas of stainless steel castings.
Powder Coating:
A surface treatment method for spraying plastic powder onto stainless steel castings. Like painting, there are different colors selected.
Glass Bead Blasting
Glass bead blasting method to refine the surface of stainless steel castings. The surface smooth of sand glass bead blasting looks better than shot blasting. But the cost is higher.
Brush Finishing
A brushed finish typically has a uni-directional satin finish. The brushing gives cast stainless steel parts a distinct look. It retains parts’ metallic luster and is given a pattern of very fine lines parallel to the brushing direction.
Pickling & Passivation
Pickling is a chemical treatment way to eliminate surface dirt like oxide skin, rust, and welding spots. Passivation is a process that forms a new abundant chromium protective layer. It can improve the anti-oxidation ability of stainless steel castings.
China Top Stainless Steel Casting Factory
Hengke Metal Foundry is one of the largest casting and machining companies in China. We have our own foundry and CNC Center workshop. The customized stainless steel castings range can be from 0.03kg-100kgs. The raw materials can cover all stainless steel grades.
Why Choose Hengke Metal ?
Hengke Metal has been the most reliable one-stop source for stainless steel castings. With The competitive prices and full services of stainless steel castings, we have exported our goods to Japan, US, UK, Canada, Australia, South Africa market. If you have any stainless steel casting inquiries, contact us freely. You will get a prompt reply within 6 hours.