301, 304, 304L, 316, 316L, 309S, 310, 321 Large diameter centrifugally cast stainless steel pipe, ASTM A249, A269, A213, A312

1. Specifications of Large-diameter stainless steel pipe

Equivalent  grades

2. What is a large-diameter centrifugally cast stainless steel pipe?

The process of centrifugal casting involves injecting liquid metal into a quickly spinning mold. Strong centrifugal force causes the molten metal to fill the mold, and casting is created after cooling.

These procedures and methods depend on the centrifugal force produced by rotation to spread the metal present to the circle's outer edge. The molten metal is kept at the edge by centrifugal force long enough for it to solidify and eventually transform into a superior substance that can withstand even the most extreme conditions.

A centrifugal casting machine must be utilized to produce the necessary conditions for the mold to revolve in order to carry out the aforementioned procedure. The centrifugal casting method is often classified into two types: horizontal and vertical, depending on the various spatial positions of the mold rotating axis.

The horizontal axis is the axis around which the horizontal centrifugal casting mold spins. It is mostly employed to create castings for pipes and sleeves with uniform wall thickness. The vertical axis is the axis around which the vertical centrifugal casting mold spins. It may make special-shaped castings in addition to the more common circular and cone ring castings.

Why is centrifugal casting important?

The greatest quality can be produced using the centrifugal casting method without incurring additional costs or machining demands. To comprehend how extreme these circumstances can be, consider applications in the maritime and aircraft industries. The fundamental specifications in both situations depend on the overall caliber of the content.

The sea environment is quite abrasive and full of corrosive substances like oil spills and other debris. The corrosion process is accelerated by the outside atmosphere and the sun's UV radiation. Similar to this, materials that can resist extremely high temperatures and velocity are frequently needed for aeronautical applications.

In all situations, the materials must be of the best possible quality. Every stage, from material procurement to processing, must guarantee that the material's general qualities are appropriate for the application. You must use a top-notch procedure to accomplish this.

The centrifugal casting process typically involves the following steps:

1 Mold Preparation:
To provide effective thermal insulation and avoid metal-metal contact, the interior of the mold is coated with a refractory substance. This coating also makes it simpler to remove the cast that has formed.

2 Mold Assembly:
The pouring system is put together, and the mold is positioned firmly on the rotating casting machine. Depending on the size and substance being cast, the machine rotates at high rates, often between 300 and 3000 revolutions per minute (RPM).

3 Metal Melting:
In a furnace, the chosen metal or alloy is melted while preserving the ideal temperature and chemical makeup for the casting.

4 Pouring:
Through the pouring mechanism, the metal is poured into the revolving mold once it has reached the proper temperature and composition. The molten metal is forced to spread evenly by the centrifugal force produced by rotation, filling the mold cavity.

5 Solidification:
The molten metal starts to cool and solidify as it fills the mold. As a result of the centrifugal force's promotion of directed solidification, a fine-grained structure with enhanced mechanical characteristics is produced.

6 Cooling and Ejection:
The spinning is halted and the casting is allowed to cool when the metal has solidified. The finished casting is extracted from the mold when the casting has cooled.

Advantages of centrifugal casting:
1. The molten metal is filled and solidified under the action of centrifugal force that is tens or hundreds of times greater than that of gravity, resulting in a good feeding effect, easy discharge of inclusions and gases, dense casting structure, and mechanical properties that are similar to those of forging; 2. Since castings are typically cooled from the outside to the inside, directed crystallization results, which enhances the castings' mechanical and physical qualities; 3. There is no requirement for core-making or molding, saving money on the purchase of relevant supplies and machinery; 4. There is no core needed when producing hollow castings, so the metal filling ability can be greatly improved when producing long tubular castings. Firmness of the joint surface and preservation of precious metal materials. 5. There is almost no metal consumption in the gating system and riser system, which improves material utilization; 6. It is convenient to produce bimetallic composite castings, such as steel-backed copper sleeves, bimetallic rollers, etc.

Disadvantages of centrifugal casting:
1. It is unsuitable for the production of materials that are prone to specific gravity segregation, such as lead bronze, aluminum-magnesium, and other alloys; 2. It has certain limitations when used to produce special-shaped castings; 3. It has large dimensional errors, many pores, and slag inclusions, and requires a lot of machining.

3. Main stainless steel product grade comparison table