|Steel Grade||Chemical Composition %|
Rb / MPa
A / %
Reduction of Area
Normally we will follow 75K standard.
ZG25CrNiMo is a specific type of cast steel commonly used in blowout preventer castings.
It exhibits good strength and toughness, making it suitable for applications involving high loads and impact forces.
Wear Resistance: The presence of chromium contributes to the material's wear resistance, making it suitable for abrasive environments.
Corrosion Resistance: The combination of chromium and nickel provides moderate corrosion resistance, protecting the material from certain corrosive environments.
Heat Resistance: ZG25CrNiMo has reasonable heat resistance, allowing it to withstand elevated temperatures without significant loss of mechanical properties.
Machinability: While it is possible to machine ZG25CrNiMo, it tends to have relatively lower machinability compared to some other materials.
An important value for ZG25CrNiMo castings is impact in low temperature.
We will do the quenching to get qualified value.
1)The engineer will firstly prepare the technology and do a simulation before pouring.
Our factory is established in 2003,the chief engineer is the second genaeration.
2)We will make a pattern of the BOP castings based on engineer's technology.
It will cost us around one week.
After that the engineer will check the dimension and make a record.
pattern for shipbuilding
wooden pattern for cement mill castings
A good pattern making is necessary.
3)Sand molding making will be made by experienced wokrers.
Their salary is decided by the quality and most of them have more than 10 years' experience.
In our mind,they are not only workers,but also can be called technicians or artists.
4)Pouring and cooling.
There are one 8tons electrical arc furnace;
Two 50 tons medium frequency furnace;
One 120 tons refining furnace and one 120 tons VD furnace;
We upgrade our furnace and now at least melting steel 45 tons per time.
5)Clean the sand and cut the riser after normalizing
clean the beam
clean the beam 2
6)Heat treatment will cost 7days( 4 days normalizing and 3 days tempring).
There are 8 heat treatment furances with max. one is 12m*9m*6m.
7)dimension check and draw a line for machining.
Before we do the rough machining,we should firstly check the dimension to see whether there is enough allowance.
rough machined shell
9)NDT withe qualified inspector
10)Welding repair if needed and tempering for stress relief.
The welders have neccesary welding certificate.
11)Final machining and NDT
12)Customers' inspection and packing
Haian Haitai Casting Co.,Ltd. is established in 2003.
We supply large steel castings with low carbon or alloy steel from 3 tons to 190 tons single weight.
With a quick development,now we had supplied steel castings 6,000 tons per month.
There are three workshop for sand mold making,one workshop for machining and one for post procedure.
We have rich experience to supply castings for BOP of Russian market.
Every month we supply 1000 tons petroleum machinery casting parts for Hebei Province Renqiu City,Shanghai Shenkai Group,Yanchen city and some Russian customers.
For the castings of oil and gas,we have API 20A certificate.
|No. ||Equipment Name||Quantity(Set)|
|1||Sand analysis equipment||1|
|2||Impact sample low temperature meter||1|
|3||Direct reading spectrometer(OXFORD)||2|
|5||ZEISS metallurgical microscope||1|
|6||Pendulum impact tester||1|
|7||Microcomputer controlled electro-hydraulic servo universal test machine||5|
|8||Various hardness tester||4|
|9||Magnetic defect detector||5|
|10||Ultrasonic flaw detector(digital)||1|
|11||CX-52 Total station||1|
|12||Stylus roughness meter||1|
We do the test according to diffrent production step,
such as chemical composition,UT,MT and mechanical property.
In 2021,Haitai inspection and testing center got approval from CNAS.
Our company is near to Shanghai port and we can supply different packing according to customers' specification.