Contact Platform Support
Help Center20crmovtib4-10 Alloy Structural Steel Bars for High-strength Bolt Fasteners, 1.7729 Round Steel Forgings
Related Products
-
Heat-resistant 45cr14ni14w2mo Stainless Steel Ingot, Corrosion-resistant S32590 Bright Round Bar, 40cr14ni14w2mo Round SteelUS$ 1.46 - 1.77MOQ: 10 Kilograms -
Alloy Tool Steel 5crw2si Round Steel, 4crw2si Tool Steel Bars, Long Steel With Diameters From 16 to 200 and Complete SpecificationsUS$ 1.46 - 1.77MOQ: 10 Kilograms
-
Mold Steel H13r Round Steel, Heat-resistant H13esr Electroslag Round Bar, Can be Cut and Sold Retail From 16 to 600, Guaranteed for Flaw DetectionUS$ 1.46 - 1.77MOQ: 10 Kilograms
-
National Standard High-quality Carbon Tool Steel T10a Round Steel, T8a Round Bar. High Hardness and Good Wear Resistance. Available in Sizes From 14 to 280mm.US$ 1.46 - 1.77MOQ: 10 Kilograms
-
15crni3mov Alloy Steel Bar With Low-temperature Toughness, 15crni3mova Round Steel Resistant to Seawater Corrosion, Diameter 16 - 300US$ 1.46 - 1.77MOQ: 10 Kilograms
In extreme working condition fields such as petrochemical, shipbuilding, mining machinery, and nuclear industry, high-strength bolt fasteners have long faced severe challenges such as connection loosening, stress relaxation, and fatigue fracture. Traditional alloy structural steels often struggle to balance strength and toughness, leading to premature failure of bolts under high temperature, high pressure, or alternating loads. This not only incurs high maintenance costs but may also cause safety accidents. Liaocheng Jincheng Yangming Special Steel Co., Ltd. has deeply understood this industry pain point. Relying on years of experience in special steel smelting and forging, it has launched the 20CrMoVTiB4-10 alloy structural steel bar (1.7729 round steel forging) specially designed for high-strength bolt fasteners. Through precise control of microalloying elements such as chromium, molybdenum, vanadium, titanium, and boron, this material ensures ultra-high strength while endowing excellent impact toughness and fatigue resistance, solving the shortcoming of fastener lifespan at the source. The company is located in Liaocheng City, Shandong Province, and has long been committed to the research and development and production of high-end special steels such as precipitation-hardening steels, duplex steels, heat-resistant steels, and corrosion-resistant alloys. Its products are widely used in aerospace, ships, mines, and construction machinery. We adhere to the principle of "seeking truth from facts and honesty as the foundation", polish technical details to the extreme, and ensure that each round steel forging can meet the most stringent bolt manufacturing requirements.
The working mechanism of this product relies on a fine alloying design and multiple heat treatment processes. First, the chemical composition of 20CrMoVTiB4-10 is scientifically proportioned: the carbon (C) content is controlled at 0.17%~0.23% to provide basic strength; the chromium (Cr) content is 1.20%~1.50%, and the molybdenum (Mo) content is 0.60%~0.80%, which significantly improves hardenability and high-temperature strength; the vanadium (V) content is 0.30%~0.50% for fine-grain strengthening; the trace addition of titanium (Ti) and boron (B) (Ti 0.04%~0.10%, B 0.0005%~0.003%) can refine grains and improve tempering stability. During the forging process, the company uses a large-tonnage rapid forging press in combination with a temperature control system to weld the internal looseness and segregation of the steel ingot, obtaining a dense and uniform fibrous structure. After subsequent quenching and tempering treatment (quenching + high-temperature tempering), a tempered sorbite structure is finally obtained, with excellent comprehensive mechanical properties. The product features include:
- Ultra-high strength level: The tensile strength can reach 1000~1200MPa, and the yield strength is ≥900MPa, meeting the requirements of grade 10.9 and even grade 12.9 high-strength bolts.
- Excellent fatigue and relaxation resistance: The fine grain size (above grade 7) and uniform carbide distribution enable the bolts to maintain a stable pre-tightening force under high-frequency vibration.
- Good low-temperature toughness: The impact energy at -40℃ is ≥27J, suitable for cold regions and deep-sea projects.
- High dimensional accuracy: The diameter tolerance of the round steel can be controlled within ±0.5mm. The outer circle of the forging is smooth, reducing the subsequent machining allowance.
- Customizable: We support delivery in the black skin state and the turned state, and can provide forging blanks according to the customer's drawings.
| Technical parameters | Typical values | Remarks |
| Tensile strength (MPa) | 1100~1200 | Quenched and tempered state |
| Yield strength (MPa) | ≥950 | 0.2% residual deformation |
| Elongation after fracture (%) | ≥12 | Standard specimen |
| Reduction of area (%) | ≥45 | Typical value |
| Impact energy (J, -40℃) | ≥27 | V-notch |
| Hardness (HBW) | 320~380 | Can be adjusted according to requirements |
Compared with traditional materials such as 40Cr and 35CrMo, the high-temperature strength of 20CrMoVTiB4-10 below 600℃ is increased by about 30%, and the anti-hydrogen embrittlement ability is significantly enhanced. It is particularly suitable for petrochemical flange fasteners in corrosive media containing hydrogen sulfide. In wind power and mining machinery, the bolts made of this material can withstand long-term alternating loads without relaxation, effectively extending the equipment maintenance cycle. We provide a complete quality guarantee: each batch of materials comes with a chemical composition report, a mechanical property report and an ultrasonic flaw detection record to ensure zero-defect delivery.
Since its establishment, Liaocheng Jincheng Yangming Special Steel Co., Ltd. has always adhered to the business philosophy of "integrity-based and excellence-seeking". The company is equipped with advanced testing equipment such as direct-reading spectrometers, universal testing machines, low-temperature impact testing machines and ultrasonic flaw detectors, which can control the whole process of raw materials and finished products. Our products have been successfully applied to many national key projects: for example, the high-temperature and high-pressure bolts of a large petrochemical base, the high-strength connectors of an offshore wind power platform, and the fastening systems of nuclear power auxiliary equipment have all been highly recognized by customers. The company has maintained stable cooperation with many large domestic fastener manufacturers all year round, with a cumulative supply of alloy steel round forgings exceeding 5000 tons and a product return rate of less than 0.5%. We are well aware that although fasteners are small, they are related to equipment safety and people's lives and property. Therefore, whether you need standard specifications or non-standard customization, we can provide professional material selection suggestions and technical support. If you are looking for a high-strength bolt raw material that can handle extreme working conditions, we sincerely invite you to contact us. We will recommend the most suitable supply state and heat treatment process according to your specific usage conditions (such as temperature, medium, load type). Choosing Jincheng Yangming Special Steel means choosing reliability and peace of mind.
FAQ
Q1: What are the differences between 20CrMoVTiB4-10 and Japanese SCM420 or American 4140?
A: Both SCM420 and 4140 are medium-carbon alloy steels, while 20CrMoVTiB4-10 adds microalloys such as vanadium, titanium, and boron, resulting in finer grains and higher tempering stability. At the same hardness, the impact toughness of 20CrMoVTiB4-10 is about 40% higher than that of 4140, and the fatigue life is increased by more than 2 times. It is more suitable for long-life and high-strength bolts.
Q2: Can this material be used in low-temperature environments below -50℃?
A: The lower limit of low temperature for typical applications is -40℃ (impact energy ≥27J). If a lower temperature (such as -60℃) is required, the low-temperature toughness can be further improved by adjusting the heat treatment process (such as subcritical quenching), but targeted trial production and verification are required. We can provide low-temperature impact test data for evaluation.
Q3: What is the maximum supply size of round steel forgings?
A: The conventional specification has a diameter of 20~300mm, and the length of a single piece can reach 6 meters. If a larger diameter (such as over 350mm) or special-shaped forgings are required, they can be produced by the open die forging process, and the maximum weight can reach 5 tons per piece. Please provide the drawings or technical requirements specifically.
Q4: What are the differences between the black scale surface and the turned surface of the product? How to choose?
A: The black scale state retains the hot-rolled oxide scale, with lower cost, and is suitable for subsequent rough turning. The turned surface state has removed the oxide scale and decarburized layer, with high dimensional accuracy (tolerance ±0.3mm), and can be directly used for precision machining. If the final machining allowance of the bolt is small, it is recommended to choose the turned surface state to save cutting tools.
Q5: Can your company provide guidance on the heat treatment process?
A: Yes. We can provide customers with the recommended quenching temperature range (860~900℃) and tempering temperature range (550~650℃), as well as the reference for tempering time. For mass production, we can also assist in formulating the process specification and trial-produce small samples to verify the mechanical properties.
Q6: Is this material suitable for scenarios with high outdoor anti-corrosion requirements, such as bolts for photovoltaic supports?
A: 20CrMoVTiB4-10 itself is an alloy structural steel with general corrosion resistance. If high corrosion resistance is required, the bolt surface can be treated with dacromet, hot-dip galvanizing, or zinc-aluminum coating. Our material has high cleanliness and good surface adhesion, which is suitable for subsequent anti-corrosion processes.
Q7: How to ensure the stability of the quality of each batch?
A: We control from the source: carefully select high-quality scrap steel and alloy raw materials, adopt LF+VD refining and degassing to reduce the content of harmful elements and gases. After forging, each piece is subjected to ultrasonic flaw detection, and the mechanical properties are tested in batches according to the furnace number. Third-party test reports (such as SGS) can be provided to ensure traceability.
Q8: Can you provide samples for trial production? What is the minimum order quantity?
A: We support the paid sample service. The sample specifications are with a diameter of 20~100mm and a single length of 200mm. The minimum order quantity for bulk orders is 2 tons, but it can be negotiated according to the customer's credit and project background. Our aim is to help customers verify the applicability of the materials.
Send Inquiry to This Supplier
You May Also Like
-
High-toughness 37simn2mov Low-temperature-resistant Round Steel, High-strength 30cr2ni2moa Alloy Steel Bars, Available for Cutting and RetailUS$ 1.46 - 1.77MOQ: 10 Kilograms
-
High-strength Heat-resistant A335p22 Alloy Round Steel, Corrosion-resistant Sa213 T22 Round Bar and Forged Round, With a Complete Range of SpecificationsUS$ 1.46 - 1.77MOQ: 10 Kilograms
-
Jinchengyangming Fatigue-resistant 35crmova Round Steel, High-toughness 35crmov Alloy Steel Bar, Sold by One Piece. InterruptedUS$ 1.46 - 1.77MOQ: 10 Kilograms
-
American Standard Astm A350 Lf5 Alloy Round Steel, Low-temperature Resistant A350 Lf6 Round Bar Forgings, Cut and Sold Retail From 55 to 200US$ 1.46 - 1.77MOQ: 10 Kilograms
-
High-toughness 1.5752 Carburized Round Steel, 14nicr14 Round Steel for Machining, European Standard 15nicr13 Alloy Steel BarUS$ 1.46 - 1.77MOQ: 10 Kilograms
-
09crcusb Low - Alloy Round Steel Resistant to Sulfuric Acid Dew Point, Low - Temperature nd Steel Rod for Power Plant Boilers, Large - Sized Reformed Small RoundsUS$ 1.46 - 1.77MOQ: 10 Kilograms
-
High-strength Medium-carbon Alloy Structural Round Steel of 40crmnmoa, Alloy Round Bar for Heavy-duty Gear Shafts of 20crmnmoaUS$ 1.46 - 1.77MOQ: 10 Kilograms
-
Valve Forging A350 Lf2/lf3/lf5/lf6 Low Alloy Round Steel, Low Temperature Alloy Round Bar, Quality Assurance With GoodsUS$ 1.46 - 1.62MOQ: 10 Kilograms
-
Low-alloy High-strength 39nicrmo3 Chromium-nickel-molybdenum Alloy Steel, German Standard 1.6510 Steel for Aerospace Engine ShaftsUS$ 1.46 - 1.62MOQ: 10 Kilograms
-
High-hardness Roll Steel 85cr3mo Round Steel, High-wear-resistant 85cr5mo Alloy Steel Bar, Non-standard Customization, Fast DeliveryUS$ 1.46 - 1.62MOQ: 10 Kilograms
