The date of payment from buyers deliver within days
Ductile iron,Iron,stainless Steel,Carbon Steel, Alloy Steel or on request of customer
investment casting process and machining.
As per the customer's drawings and requirements
painting, polishing, galvanization etc and as per customers" requirement
Annealing, normalizing ,quenching+tempering,solution treatment and as per customer's requirement.
Factory in-house self check or Third Party inspection
By sea, air or express according to customers' requirement
1. How to get a quotation?
Please send us drawings in igs, dwg, step etc. together with detailed PDF.
If you have any requirements, please note, and we could provide professional advice for your reference.
2. What if we do not have drawing?
Samples would be available, and we would send you drawing to confirm.
Of course, we would ensure the safety of the drawing.
3. How to pay?
For small quantity, we could provide Paypal, Paypal commission will be added to the order.
For the big one, T/T is preferred.
4. How to ship?
For small quantity, we have cooperation with TNT, FEDEX, UPS etc.
For big quantity, air or sea would be available for you to choose.
5. What about the packing details?
We attached our normal packing details.
If you have any special requirements, we would be willing to help.
6. What about the delivery time?
It would be 20-30 days normally for the parts to be ready and we had a system to ensure the time.
When you made your order, you would know.
investment casting process
Step 1: Mould engineering & production
With precision investment castings, the first step involves the engineering and production of a mould also known as a wax tool. Moulds are made from aluminum or steel. This mould is developed in-house by hoohi engineers and serves as a negative of the final casting. It is important that the mould is made accurately, so that the required tolerances and surface roughness can be achieved. Depending on the size of the series, the mould is installed either onto a manual or automated press.
Step 2: Wax model spraying & Tree building
The mould is filled with liquid wax. After the wax has been cooled down, ejectors in the mould push the wax model out. A wax model has now been sprayed which is identical to the final casting. These wax models are glued onto a so-called wax tree with a casting funnel on top, into which steel is poured in a later stage of the process
Step 3: Rinsing the wax trees
After the wax models have been glued onto a wax tree, they are rinsed. Any possible contaminations on the surface are removed to ensure a successful attachment of the ceramic onto the wax tree.
Step 4: Building ceramic layers
After rinsing the wax tree, the tree is given a fireproof ceramic shell. This shell is constructed after repeatedly submerging the tree (up to 7 or 9 times) in a slurry and sprinkling it with ceramic sand. The ceramic layers are then hardened in a drying chamber where they are exposed to air.
Step 5: Autoclave
After the layers have been formed and dried, the wax is melted out of the ceramic tree by using steam (120°C) in an autoclave. This is why it is called “lost wax casting”. The majority of the molten wax can be regenerated and is reusable.
Step 6: Sintering
The ceramic tree is then baked (stoked) at temperatures of around 1100°C and reaches its final strength through the sintering process. Any wax remains are burned out during this process.
Step 7: Casting
The desired steel alloy is melted in a large furnace and brought to cast temperatures. The ceramic tree is, at the same time, heated in an oven to prevent thermal shocks during the pouring process. After the tree has been heated, it is removed from the oven by a robotic arm and filled up with a steel alloy by use of counter gravity. When the trees have been poured, they are placed on a cooling conveyor where they are cooled down. (with nitrogen).
Step 8: Ceramic removal
The trees are then removed from their ceramic shell by using a fully-automatic hammer to break the shell. This removes the majority of the ceramic. The next step is to cut the products from the trees by sawing or vibrating. The steel leftovers will be sorted based on alloy and can be melted again during the next casting session
Step 9: Blasting
The Finishing Department removes the last pieces of ceramic by means of steel, sand and/or water blasting.
Step 10: Grinding
The ingate which remained after the sawing process, is grinded from the casting. To grind the product properly, a grinding fixture is often applied.
Step 11: Visual inspection
The Quality Department checks all products visually for possible casting failures. This check takes place according to a quality standard sheet to ensure that all possible surface failures are corrected properly. Thanks to this procedure, you can be assured that hoohi only delivers high quality castings.
Step 12: Machining
hoohi has the capabilities to machine castings in house, such as drilling holes, tapping threads and turning & milling activities. This enables hoohi to deliver a completely machined component that is ready-to-install.
Step 13: Heat and- or surface treatment
Some alloys require heat treatment to achieve a certain hardness, tensile strength or elongation according to 2D drawing specifications. The standard heat treatments are performed in-house, the complex treatments are outsourced. hoohi also has the know-how to perform a surface treatment for a casting. Surface treatments involve the coating process of a steel surface, to enhance the looks of the surface or protect it against external influences such as corrosion (rust) and natural wear (damage).
Step 14: Final inspection
The final step in this process is another visual check and when necessary composing a measurement report and material analysis. After the final inspection, the products are ready for shipment to another satisfied Hoohi customer.
The Elements Used in Steel
Carbon (C): Carbon, a nonmetallic element, forms a number of organic and inorganic compounds and can be found in coal, petroleum and limestone. It is the principle strengthening element in carbon steels and low-alloy steels. Atomic number 6, atomic weight 12.01115.
Manganese (Mn): Manganese is a brittle, metallic element that exists in the ore of pyrolusite. When making steel, it reacts with sulfur and helps to increase the metal's resistance to heat. Atomic number 25, atomic weight 54.9380.
Phosphorus (P): Phosphorus is a poisonous, nonmetallic element that helps protect metal surfaces from corrosion. Atomic number 15, atomic weight 30.9738.
Sulfur (S): Sulfur is a nonmetallic element found mainly in volcanic and sedimentary deposits. Sulfur, in the form of iron sulfide, can cause steel to be too porous and prone to cracking. Atomic number 16, atomic weight 32.064.
Silicon (Si): Silicon is the second most abundant element in the earth's crust and can be found in rocks, sand and clay. It acts as a deoxidizer in steel production. Atomic number 14, atomic weight 28.086.
Nickel (Ni): Nickel is a hard, metallic element that found in igneous rocks. Without nickel, stainless steel would be less resistant to heat and corrosion. Atomic number 28, atomic weight 58.71.
Chromium (Cr): Chromium, a metallic element, is found in the earth's crust. It is used in the production of stainless steel to make the steel resistant to oxidation and corrosion. Atomic number 24, atomic weight 51.996.