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S41428 (UNS S41428) is a high-temperature martensitic stainless steel for forgings and forging stock. It meets the ASTM A1021/A1021M standard and is called Grade C in that standard.
This steel adds nickel (2.25–3.25%) and molybdenum (1.5–2.0%) to basic martensitic stainless steel. These additions greatly improve its corrosion resistance and high-temperature strength.
S41428 forgings are made for high-temperature service. Its mechanical properties come from proper heat treatment – heating, quenching, and tempering.
This material has high strength, good toughness, and excellent corrosion resistance. It is an ideal choice for key parts that work under high temperature and high pressure.
Element | % | Explication |
C | 0.10 - 0.17 | Ensure strength and hardenability |
Si | ≤ 0.35 | Detoxifier, enhances antioxidant properties |
Mn | 0.65 - 1.05 | Improve hardenability and strength |
P | ≤ 0.020 | Strict control, ensuring resilience |
S | ≤ 0.015 | Strict control to ensure the heat processing property |
Cr | 11.25 - 12.75 | Core corrosion-resistant element, providing antioxidant properties |
Ni | 2.25 - 3.25 | Significantly enhance corrosion resistance and toughness |
Mo | 1.50 - 2.00 | Improve resistance to pitting corrosion and high-temperature strength |
V | 0.25 - 0.40 | Refine the grains and enhance the high-temperature strength |
铜 (Cu) | ≤ 0.50 | Improve corrosion resistance |
铌 (Nb) | ≤ 0.20 | Refine the grains and enhance the strength |
氮 (N) | ≤ 0.020 - 0.045 | solution strengthening |
Item | Class1 | Class2 |
tensile strength (min) | 160 ksi [1105 MPa] | 140 ksi [965 MPa] |
yield strength 0.2% (min) | 120 ksi [825 MPa] | 90 ksi [620 MPa] |
elongation (min) | 13% | 15% |
reduction of area (min) | 30% | 35% |
impact energy (average, min) | 40 ft-lb [54 J] | 8 ft-lb [11 J] |
impact energy (unit, min) | 27 ft-lb [36 J] | 5 ft-lb [7 J] |
brinell hardness (max) | 352 | 331 |
rockwell hardness (max) | 38 | 36 |
Heat treatment includes austenitization, quenching and tempering.
Re-tempering is allowed, but more than one complete reheat treatment requires the buyer's approval.
After straightening, stress relief heat treatment must be carried out.
After stress relief, liquid quenching is prohibited.
Industry | Application |
Petrochemical industry | Refining equipment reactors, towers Chemical reaction vessels, distillation equipment High-temperature resistant sulfur-containing, acidic oil and gas pipelines Special steel pipes for the fertilizer industry (urea, phosphate medium) |
Electrical energy | High-temperature steam pipelines and valves of thermal power plants Structural components of nuclear energy facilities Blades of gas turbines and compressor airfoils Heat exchangers and heat exchange pipe systems |
Aerospace | High-temperature components of the aeroengine Compressor blades |
Vessel traffic | Corrosion-resistant components of fire vessels Structural materials for offshore platforms Seawater desalination equipment, seawater exchangers |
The global stainless steel forging market is growing steadily. In 2024, the market value was about 12.98 billion US dollars. By 2031, it is expected to reach 18.46 billion US dollars, with an annual growth rate (CAGR) of about 5.3%. The US market was worth about 2.6 billion US dollars in 2024, and the Chinese market is expected to reach about 2.7 billion US dollars by 2030.
For the martensitic stainless steel segment, global production in 2025 is estimated at 8.9 million tons, with a market size of about 28.459 billion US dollars. For martensitic steel used in precision casting, global production in 2025 is about 230,000 tons, and the average price is about 1,850 US dollars per ton. From 2026 to 2032, the market growth rate (CAGR) is expected to be about 4.2–4.5%.
The demand for S41428, as a high-end special stainless steel, is driven mainly by these factors:
Upgrading of the energy industry: Global power generation (coal, nuclear, and new energy) needs more materials that can resist high heat and corrosion.
Deep processing in petrochemicals: More integrated refining and chemical projects require strong steel for high-temperature and high-pressure equipment.
Recovery of aerospace: The global aviation industry is coming back, which increases demand for high-end blade materials.
Import substitution: China's high-end equipment manufacturing is growing, so there is more demand for American-standard high-end materials like S41428.
S41428 is a high-end martensitic stainless steel, and its price is influenced by multiple factors.
Effect Factors | Description |
raw material | The price fluctuations of alloy elements such as nickel and molybdenum |
process | The dimensions, precision and heat treatment requirements of the forgings affect the processing cost. |
qty | The larger the batch size, the lower the unit cost. |
surface condition | Rough processing vs. Fine processing, there is a significant price difference. |
Certification | A compliance test report in accordance with ASTM A1021 must be provided. |
In the first half of 2026, the price of domestic 400-series stainless steel (such as 2Cr13) stayed at 1100–1300 USD per ton.
S41428 is a high-end grade that contains nickel and molybdenum, so its price is much higher than normal 400-series steel. It is usually priced based on the same system as molybdenum-containing stainless steels like 316L.
In August 2026, the price of 316L forged round bar was about 4200–4500 USD per ton.
The price of S41428 forgings is expected to be between 5000 and 8000 USD per ton, depending on size, precision, and order quantity.
Strictly compliant with ASTM A1021/A1021M‑20(2025) – full‑process quality control.
Full size customization – thickness from 150 mm to 500 mm, width can be customized.
Complete heat treatment services – annealing, quenching + tempering, all steps available.
Third‑party testing support – full reports available for mechanical properties, chemical composition, grain size, non‑destructive testing, etc.
Extensive industry experience – deeply experienced in the forging of high‑temperature martensitic stainless steels.
Q1: What is the difference between S41428 and normal 410 stainless steel?
A: S41428 (Grade C) adds 2.25–3.25% nickel and 1.5–2.0% molybdenum to 410 steel. Nickel makes it better against rust and tougher. Molybdenum helps it resist pitting and stay strong at high heat. S41428 must have tensile strength above 160 ksi (1105 MPa), much higher than normal 410.
Q2: What heat treatment choices are there for S41428 forgings?
A: According to ASTM A1021, S41428 can be supplied in three conditions:
Class 1: Quenched + tempered – highest strength (tensile ≥160 ksi)
Class 2: Quenched + tempered – better toughness (higher impact requirement)
Class 3: Annealed – for users who will do their own heat treatment later
Q3: Can S41428 forgings be welded?
A: Yes, S41428 has good weldability. Many welding methods can be used, and the material stays stable after welding. But as a martensitic stainless steel, you need to preheat and do post-weld heat treatment to avoid cracks. It is best done by skilled welders.
Q4: What technical papers do I need when buying S41428 forgings?
A: Per ASTM A1021, the supplier should give:
Material certificate (with chemical analysis)
Mechanical test report (tensile, impact, hardness)
Heat treatment records
Non-destructive test reports (if needed)
Size inspection report
Q5: What is the biggest size of S41428 forgings you can supply?
A: The maximum size depends on the forging method and equipment. Open-die forging can make large parts; closed-die forging is for small to medium precision parts; ring rolling is for rings. Please ask your supplier for specific sizes based on your drawings.
Q6: Is there a Chinese GB grade that matches S41428?
A: Not exactly. There is no full match in the Chinese GB standard. It is best to order using UNS S41428 or ASTM A1021 Grade C directly.
Q7: How long does it take to deliver S41428 forgings?
A: Delivery time depends on size, quantity, and heat treatment needs.
Standard bars: usually 2–4 weeks
Custom forgings (need new dies): usually 4–8 weeks
Special needs or large orders: may take longer. Please check with your supplier early.
Q8: How can I make sure the S41428 forgings I buy meet ASTM A1021?
A: You can do these things:
Ask the supplier for a statement that they follow ASTM A1021
Check the material certificate – confirm chemical composition meets Table 2
Check the mechanical test report – confirm it meets Table 3 or Table 4
Have a third-party lab do extra tests if needed
Choose a supplier with ASTM certification and a good reputation
