High Strength Structural Steel Plate (High strength , high yield point)

JBL High-strength plate grade(Q390、Q420、Q460、Q500、Q550、Q690、Q800、Q890、Q960) 

  • Q390: Yield ≥ 390 MPa; Regular low-alloy steel; Application: General heavy structures, medium-sized bridges.

 

  • Q420: Yield ≥ 420 MPa; Balanced comprehensive performance; Application: Columns of high-rise buildings, large-span trusses.

 

  • Q460: Yield ≥ 460 MPa; Lower alloy strength limit (hot-rolled state); Application: Main materials of special heavy structures such as bird’s nests.

 

  • Q500: Yield ≥ 500 MPa; Begins to involve quenching and tempering process; Application: High-pressure vessels, high-end construction machinery arms.

 

  • Q550: Yield ≥ 550 MPa; Entry-level quenched and tempered steel; Application: Mining machinery, key load-bearing components of large ships.

 

  • Q690: Yield ≥ 690 MPa; Typical ultra-high strength quenched and tempered steel; Application: Crane booms, wind turbine towers, military equipment.

 

  • Q800: Yield ≥ 800 MPa; Extremely high strength, difficult welding; Application: Special vehicle chassis, aerospace structures.

 

  • Q890: Yield ≥ 890 MPa; Extremely high-end quenched and tempered steel; Application: Extreme load conditions, special protective structures.

 

  • Q960: Yield ≥ 960 MPa (thickness ≤ 50mm); Current first-tier civilian engineering; Application: Super high-rise core tubes, super large-span bridge towers.

What is high-strength plate?

High-strength plates, also known as high-strength steel plates, low-alloy high-strength plates, and high-strength welded plates.

What are the differences between high-strength plates and ordinary steel plates?

High-strength steel plates are suitable for engineering and manufacturing fields where higher material performance is required, while ordinary steel plates are suitable for general purposes.

In what aspects does the “high strength” of high-strength plates lie?

“High strength, high toughness, high wear resistance and high corrosion resistance”

What does the “Q” in the high-strength plate designation mean?

Q stands for the initial letter of the Chinese pinyin for the yield strength of steel.

Which foreign brands correspond to China’s high-strength plates?

China 

Yield strength gradeEuropean EN standardAmerican ASTM standardJapanese JIS standard
  • Common Uses
Q355B/C/D
/E
≥355 MPaS355JR / S355J2 / S355K2A572 Gr.50SM490Building steel structures, Bridges, machinery
Q390B/C/D/E≥390 MPaS390 / S420The series is approachingA572 Gr.55SM570Construction machinery, structural components
Q420B/C/D/E≥420 MPaS420N / S420NLA572 Gr.60SM570Lifting equipment, vehicle structures
Q460C/D/E≥460 MPaS460N / S460NLA572 Gr.65 / A633SM570gradeLarge steel structures and Bridges
Q500/Q550≥500-550 MPaS500 / S550QLA656 Gr.80HSAseriesConstruction machinery, mining equipment
Q690D/E≥690 MPaS690QL / S690Q / S690QL1A514 / A517HT780Crane booms, heavy machinery
Q890/Q960≥890-960 MPaS890QL / S960QLA514height classHT980Super-large equipment, lightweight structure

What are the standards for high-strength plates?

GB/T 1591-2018 & GB/T 3274-2017&GB/T 714-2015

What are the differences between Q355B, Q355C, Q355D and Q355E?

Grade B is used for normal temperature buildings and machinery; Grade C is used for environments with temperatures above 0℃; Grade D is used for bridges and ships in extremely cold regions (-20℃ and above); Grade E is used for extremely cold environments (-40℃), such as LNG storage tanks and polar facilities.

Why does the plasticity decrease when the strength of high-strength plates increases?

The increase in the strength of high strength low alloy structural steel Plate is accompanied by a decrease in plasticity. Essentially, the strengthening mechanism enhances the material’s resistance to deformation by hindering the movement of dislocations, while simultaneously restricting the space for the material to continue undergoing plastic flow.

How is the corrosion resistance of the high-strength plate?

The corrosion resistance of Steel Plate depends on the specific material category.

Why is it necessary to strictly control the carbon content in high-strength plates?

The high strength low alloy structural steel Plate strictly control the carbon content in order to achieve high strength while also ensuring toughness, weldability and cold cracking resistance, avoiding situations of “strong but not tough” or processing failure.

How to determine the quality of high-strength plates?

The core of judging the quality of Low Alloy High Strength Hot Rolled H-Beam Steel In Steel Structural lies in verifying that “the yield strength meets the standard and the balance of toughness/plasticity is achieved”. This requires a comprehensive assessment by combining the original factory warranty certificate, chemical composition, mechanical properties (including low-temperature impact), surface and internal defect detection.

In which industries are high-strength plates mainly applied?

Excavator / Loader / Crane / Load-bearing structural components / Chassis and boom of large-span bridges / Main beams of bridge piers / High-rise buildings / Load-bearing framework of large factories / Ship hull / Deck and bulkheads / Mine cars / Hoists / Crushers / Truck frames / Trailer beams / Pressure vessels / Pipelines and storage tanks

Why are high-strength plates widely used in cranes?

Crane structures extensively utilize low alloy high strength structural steel plate, with the core purpose being to achieve structural lightweighting while ensuring the safety of load-bearing, thereby enhancing lifting capacity, operational efficiency, and reducing energy consumption.

Why do mining equipment require high-strength plates?

Mining equipment requires the use of High Yield Strength Steel . The key lies in their high strength, high toughness, and wear-resistant and impact-resistant properties, which can cope with extreme heavy loads, frequent impacts and wear conditions, while achieving lightweight structure and long service life.

How long does the high-strength plate last?

High Strength  Carbon Steel  do not have a fixed single lifespan. Their service life for structures typically ranges from 50 to 100 years, for automotive/mechanical components it is approximately 10 to 20 years, and in extremely worn-out conditions it can be just a few months. The exact duration depends on the material grade, protective process, and environmental loads.

What are the advantages of China JBL Company in purchasing high-strength plates?

  • Cost and price advantages
  • Sufficient on-site inventory
  • Support for one-stop services including CNC cutting, bending, etc. for advanced processing
  • High efficiency in matching supply and demand

What are the differences between domestic high-strength plates and imported high-strength plates?

The performance of domestic and imported high-strength plates has converged in the mid-to-low-end grades. However, in terms of high-end ultra-high-strength steel (≥1500MPa) and special coating processes, imports still have a slight edge. The core differences lie in the stability of extremely high-end materials, the technical details of surface coating, and the speed of supply chain response, rather than basic mechanical indicators.

What factors affect the price of high-strength plates?

  • Cost fluctuations /
  • Market supply and demand relationship /
  • Complexity of specifications and processes /
  • Macro logistics and exchange rates/

How to choose the steel appropriate thickness?

The selection of the thickness of high-strength plates Q355 (A/B/C/D/E) should be determined based on load calculation, reduction of thickness according to strength grade, welding process, and lightweighting goals.

How to select the grade based on the working conditions?

Identify key failure modes (temperature/medium/load/wear) → Match core performance indicators → Select corresponding material categories → Fine-tune to specific brands.

Why is the high-strength plate so strong but prone to cracking?

The characteristic of high-strength plates Q390 “high strength but prone to cracking” essentially lies in the fact that the increase in strength is accompanied by a decrease in plasticity/hardness, an increase in hardening tendency, and greater sensitivity to hydrogen/stress, resulting in a lower threshold for crack initiation and propagation.

Why is the performance of the same batch of steel plates unstable?

The performance of the same batch of steel plates Q420 is unstable. The core reason lies in the segregation of the smelting composition, the uneven distribution of internal inclusions/defects, and the fluctuations in the rolling and cooling processes, which result in inconsistent microstructures (such as banded structures and grain sizes).

What processing services are available for high-strength plates Q460?

  • Cutting and material removal //
  • Bending and shaping //
  • Hole systems and edge processing //
  • Forming and rolling //
  • Welding and assembly

What are the differences between Q355, Q420 and Q690?

If you are seeking economic efficiency and ease of construction, Q355 is the preferred choice; if you need weight reduction and moderate load capacity, choose Q420; only when space is limited and the load is extremely high, and significant weight reduction is necessary, should Q690 be selected and accompanied by strict welding process assessment

What kinds of inspection reports can JBL Company provide?

Mill Test Certificate,MTC,SGS,BV(Bureau Veritas),TUV,Intertek

 

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