P690Q is a high-strength quenched and tempered alloy structural steel. It has excellent mechanical properties, including high tensile strength and toughness, widely used in heavy machinery, engineering structures and other fields requiring high load-bearing capacity.
Chemical Composition and Mechanical Property
| Grade | C% | SI% | Mn% | P% | S% | N% | B% | Cr% | Mo% | Cu% | Nb% | Ni% | Ti% | V% | Zr% |
| P690Q | 0.2 | 0.8 | 1.7 | 0.025 | 0.015 | 0. 015 | 0.005 | 1.5 | 0.7 | 0.3 | 0.06 | 2.5 | 0.05 | 0.12 | 0.15 |
| Steel Grade | Yield Strength, for product in mm, Mpa | Tensile Strength, Mpa | Elongation, %, min | ||||
| P690Q | t≤50 | 50<t≤100 | 100<t≤150 | t≤100 | 100<t≤150 | 14 | |
| 690 | 670 | 630 | 770-940 | 720-900 | |||
Applications
Pressure Vessels and Boilers:
It is a preferred material for manufacturing pressure vessels, boilers, and heat exchangers used in petrochemical, thermal power, and chemical processing industries. These components often operate under high internal pressure and temperature fluctuations, and P690Q's excellent strength and toughness ensure safe and stable operation over long periods.
Offshore and Marine Engineering:
In offshore oil and gas exploration platforms, ship hulls, and marine pipelines, P690Q is used to withstand harsh marine environments such as saltwater corrosion, low temperatures, and strong wind loads. Its resistance to brittle fracture at low temperatures and good weldability make it suitable for offshore structural components that require high reliability.
Heavy Machinery and Construction:
It is applied in the manufacturing of heavy machinery parts, such as excavator arms, crane booms, and hydraulic cylinders, as well as large-scale construction structures like bridges and stadiums. The high strength of P690Q allows for the design of lighter and more compact components without compromising structural integrity, reducing overall equipment weight and improving efficiency.
Nuclear Power Industry:
Some auxiliary components in nuclear power plants, such as pressure pipelines and storage tanks, also adopt P690Q. It meets the strict safety requirements of the nuclear industry, providing stable performance under high pressure and radiation environments.
Processes Adopted for P690Q
Controlled Chemical Composition Process:
Strictly control the content of alloying elements during smelting. Optimize the proportion of key elements to lay a foundation for subsequent heat treatment and ensure the material's basic mechanical properties.
Hot Rolling Process:
Heat steel billets to a suitable temperature for hot rolling. Precisely control rolling speed, pressure and temperature to refine grain structure, improve material compactness and enhance overall strength.
Quenching and Tempering Process:
First, rapidly cool the rolled steel via quenching to form a martensitic structure and improve hardness. Then temper at a moderate temperature to reduce brittleness, balancing strength and toughness.
Controlled Cooling Process:
Adopt targeted cooling measures after rolling or heat treatment. Stabilize the material's microstructure, prevent deformation and ensure consistent performance across the entire batch.
Quality Inspection Process:
Implement non-destructive testing and mechanical property testing throughout production. Detect defects and ensure the final product meets technical standards for critical applications.
Why Choose Us :
You can get the perfect material according to your requirement at the least possible price.
We also offer Reworks, FOB, CFR, CIF, and door to door delivery prices. We suggest you to do deal for shipping which will be quite economical.
The materials we provide are completely verifiable, right from raw material test certificate to the final dimensional statement.(Reports will show on requirement)
We guarantee to give a response within 24hours(usually in the same hour)
You can get stock alternatives, mill deliveries with minimizing manufacturing time.
We are fully dedicated to our customers. If it will not possible to meet your requirements after examining all options, we will not mislead you by making false promises which will create good customer relations.
Contact us at beam@gneesteelgroup.com for pricing, technical support, or customized solutions. We are always ready to support your project.
What is the difference between P690Q and P690 steel?
The main difference lies in toughness requirements. P690Q has stricter impact toughness indicators, especially at low temperatures (Q stands for quenched and tempered with high toughness), making it more suitable for low-temperature or harsh working environments.
Can P690Q be used to make pressure vessels?
Yes, P690Q is suitable for manufacturing pressure vessels that bear high pressure and harsh media. Its high strength and good toughness can ensure the safety and stability of the vessel during operation, meeting relevant pressure vessel standards.
What machining methods are suitable for P690Q?
P690Q can be processed by turning, milling, drilling, and grinding. Due to its high hardness, it requires high-speed steel or cemented carbide tools, and proper cutting parameters to ensure machining efficiency and surface quality.
What is the corrosion resistance of P690Q?
P690Q has good corrosion resistance due to its alloying elements. It can resist general atmospheric corrosion and mild chemical corrosion, but in strong corrosive environments, additional anti-corrosion treatments (such as painting, galvanizing) are needed.
What is the maximum thickness of P690Q plates usually available?
The maximum thickness of P690Q plates can reach 150mm or more, depending on the manufacturer's production capacity. Thick plates are often used in heavy machinery bases and large engineering structures that require high load-bearing capacity.
What is the tensile strength range of P690Q?
The tensile strength of P690Q generally ranges from 690MPa to 830MPa. This high strength range enables it to bear large loads and is widely used in structural parts requiring high strength and reliability.
Why is P690Q suitable for heavy machinery manufacturing?
P690Q is suitable for heavy machinery manufacturing because of its high strength, good toughness, and wear resistance. It can withstand the large impact and load during machinery operation, extending the service life of equipment.
What testing methods are used for P690Q?
Common testing methods for P690Q include tensile testing, yield strength testing, impact toughness testing (Charpy test), hardness testing, and chemical composition analysis to verify whether it meets standard requirements.
Can P690Q be cold-formed?
P690Q can be cold-formed, but its cold forming performance is relatively poor due to high strength. It requires proper preheating and control of forming speed to avoid cracks and ensure the forming quality of the workpiece.
What is the role of molybdenum in P690Q?
Molybdenum in P690Q can improve its hardenability and high-temperature strength, enhance the stability of the microstructure, and increase its resistance to creep and wear, making the steel more suitable for high-load and high-temperature working conditions.