Heavy Cast Carbon Steel Stern Boss for 15500teu Container Vessel

The material is low carbon or alloy steel,such as ZG270-500,ZG42CrMo,ZG35Mn and so on.

Haian Haitai Casting Co.,Ltd. is established in 2003 in Huangqiao Town.

In 2007,we moved our factory to Sunzhuang town and now we can supply bigger steel castings with max. weight 45 tons.

In 2011,we built a new sand mold maiking workshop with 120 tons refinining furnace and the max. weight can be 120 tons.

In 2013,we paid more attenion on the castings for shipbuilding and started to supply marine castings for most of domestic famous shipyards.

From 2013 to 2023,we bought more and more machines to strengthen our ability from rough machining to finished machining.

In 2023,we built another new sand mold making workshop for the quick development of market requirement.

Now we monthly supply 6000 tons different castings for different customers of different industry,such as cement mill,shipubuilding,petroleum machinery,rolling mill,forging press and so on.

1)Pattern making

We have our own wooden pattern making workshop.
But our company is always busy,
we also have around 10 sub-contractors for pattern making.
They help us for the pattern but will be inspected according to our rules.
We will record for every pattern inspection.

2)Sand core making

We have around 80 technicans for sand core making which is divided into around 10 teams.
Most of the technicans has more than 10 years' experience.

Most of the sand core is made by silica sand with common sand inside of it.
The common sand will be used repeatly.
For some important position,such as R corner,we will use chorme ore sand.

The outside of the sand core,we will do the painting,burn and clean it.

We will assemble diffrent sand cores together and wait for pouring.

3)Melting and pouring

We always do the melting after mid-night for cheaper electric charge.
And we normally do pouring in the early morning.

4)Cooling
Chemical composition

When we do the pouring,we will also take the sample and check the chemical compositon.

After pouring,we will wait for different time for cooling according to casting's weight.

5)Heat treatment

The maximum size of the heat treatment furnace is 12m*9m*6m.
The size also decide the max. size we can make for the casting.

We only can do normalizing and tempering.
The quenching if needed will be done by our sub-contactor.

Cutting the riser,we choose thermal cutting method.

After heat treatment,we will do the mechanical property test.

6)Draw the line and do the first rough machining
We can do the machining from rough to finished machining.

7)NDT after rough machining
 

8)Welding repair
We have rich experience for making support roller,
then there is no welding for the outside working position.
This is our special technology.

But for some other castings,if we do the welding repair,
we will do the tempering for stress relief later.

All of our welders have the SGS certficate.
 

9)Final machining
We have a lot of vertical lathes from 2.5m to 10m.
 

We get approval from CNAS for our laboratory.
We also have 9 class certificate,such as ABS,DNV,NK,RINA,KR,CCS,BV and so on.
 

We supply a lot of castings for cement mill,rolling mill,shipbuilding and so on.

We can do the packing according to our rules or according to customers' requirement.

 

Normally there is a 12 months quality warantty.

We do at least three times NDT:after rough,semi-finished and finished machining.

And also the customer will do the witness during or after finished machining.

If there is also any problem when you receive the castings,
please send us photos and detailed defects,
we will negotiate with you and make a compensation.

A third party inspection before shipment is welcomed.