AISI 4150 50CrMo4 1.7228 Alloy Steel

Product Overview

AISI 4150 and its European equivalent DIN 50CrMo4 (Material Number 1.7228) are premium chromium-molybdenum (Cr-Mo) alloy steels, specifically designed for quenching and tempering. This process unlocks exceptional mechanical properties, making it the material of choice for critical components in automotive, heavy machinery, aerospace, and oil & gas industries where high stress, fatigue, and wear resistance are paramount.

As a specialized manufacturer, Hunan Qilu Steel provides this versatile alloy in a wide range of forms—including hot-rolled bars, cold-drawn bars, and custom open-die forgings—with over 10,000 tons in stock. Our material conforms to major international standards like EN 10083-3, EN 10250-3, and ASTM A29/A29M, ensuring seamless integration into global supply chains.

Steel Equivalent

Country	USA	Europe	China
Standard	ASTM A29	EN10083-3	GB/T3077
Grade	4150	50CrMo4/1.7228	50CrMo

Product Features

Chemical Composition

The alloy’s chemical makeup is meticulously controlled to balance strength, processability, and environmental resistance, with minor variations across global standards to align with regional manufacturing requirements.

Grade	C	Si	Mn	P	S	Cr	Mo
4150	0.48-0.53	0.15-0.35	0.75-1.00	0.035Max	0.040Max	0.80-1.10	0.15-0.25
50CrMo4/1.7228	0.46-0.54	0.40Max	0.50-0.80	0.025Max	0.035Max	0.90-1.20	0.15-0.30
50CrMo	0.46-0.54	0.17-0.37	0.50-0.80	0.030Max	0.030Max	0.90-1.20	0.15-0.30

Key Highlight: DIN 50CrMo4 1.7228 features a wider molybdenum range (0.15-0.30%) than AISI 4150, making it more suitable for high-temperature applications such as industrial furnace components and exhaust systems.

Mechanical Properties

Mechanical performance scales with material size, optimized for versatility across precision small parts and heavy-duty large components. All values comply with EN 10083-3 & EN 10250-3 standards, with sampling conducted 12.5mm below the heat-treated surface (per EN 10083-1).

For Machined/ Rolled Products

Mechanical properties for 50CrMo4 quenching and tempering alloy steel according to EN10083-3.

Size range	Tensile strength	Yield strength	Alongation	Area of reduction	Impact value At RT/J
d≤16 t≤8	1100-1300Mpa	900Mpa Min	9% Min	40% Min	/
16＜d≤40 8＜t≤20	1000-1200Mpa	780Mpa Min	10% Min	45%Min	30J Min
40＜d≤100 20＜t≤60	900-1100Mpa	700Mpa Min	12% Min	50%Min	30J Min
100＜d≤160 60＜t≤100	850-1000Mpa	650Mpa Min	13% Min	50%Min	30J Min
160＜d≤250 100＜t≤160	800-950Mpa	550Mpa Min	13% Min	50%Min	30J Min

For Open-Die Forgings (EN 10250-3)

Longitudinal (L) and transverse (Tr) properties are optimized for uniform performance across forging orientations, with sampling at 4/T below the surface (20mm min, 80mm max).

Size range	Tensile strength	Yield strength	Alongation		Impact value at RT/J
			L	Tr	L	Tr
d≤160	800Mpa Min	550Mpa Min	13% Min	9% Min	25J Min	14J Min
160＜d≤330	750Mpa Min	540Mpa Min	14% Min	10% Min	20J Min	12J Min
330＜d≤660	700Mpa Min	490Mpa Min	15% Min	11% Min	15J Min	10J Min

Heat Treatment & Hardenability

50CrMo4 responds exceptionally well to heat treatment, allowing precise customization of hardness and toughness for specific use cases. Hardenability is consistent across sizes, with restricted grade options (+HL, +HH) for strict industrial applications.

Standard Heat Treatment Processes

Process	Temperature Range	Cooling Method	Hardness Result	Core Application
Soft Annealing (+A)	820-860℃	Furnace-cooled	HB ≤248	Pre-machining (reduces tool wear)
Normalizing (+H)	850-900℃	Air-cooled	Refined grain structure	Improves machinability/forgability
Quenching & Tempering (+QT)	820-870℃ (soak)	Oil-quenched → 540-680℃ temper (air-cooled)	HRC 28-32 (common)	Balanced strength/ductility for most structural parts
Flame/Induction Hardening	850-900℃ (surface only)	Local quench → 180-220℃ light temper	HRC ≤58	Surface wear resistance (gear teeth, bearing surfaces)

Hardenability Grades (End Quench Test)

For critical thick-component applications, restricted hardenability grades ensure deep, uniform hardening:

• +HH Grade: Minimum HRC 42 at 50mm from the quenched end (ideal for heavy forgings)

• +HL Grade: Lower hardenability for precision machining with minimal distortion

• +H Grade: Standard hardenability for general industrial use

Detailed hardenability values (HRC) at different distances from the quenched end are available in our technical datasheet (request via sales team).

Distance in mm from quenched end
Distance		1.5	3	5	7	9	11	13	15	20	25	30	35	40	45	50
Hardness In HRC + H	max	65	65	64	64	63	63	63	62	61	60	58	57	55	54	54
	min	58	58	57	55	54	53	51	48	45	41	39	38	37	36	36
Hardness In HRC + HH	max	65	65	64	64	63	63	63	62	61	60	58	57	55	54	54
	min	60	60	59	58	57	56	55	53	50	47	45	44	43	42	42
Hardness In HRC + HL	max	63	63	62	61	60	60	59	57	56	54	52	51	49	48	48
	min	58	58	57	55	54	53	51	48	45	41	39	38	37	36	36

Scatter bands for the Rockwell - C hardness in the end quench hardenability test.

Supply Sizes, Tolerances & Surface Finishes

We offer a comprehensive range of product forms to match diverse manufacturing workflows, with tight tolerances for precision applications and cost-effective options for large-scale production. Real-time stock updates are available for all standard sizes.

Product Forms & Size Ranges

Product type	Size range	Length
Cold drawn bar	Φ3-Φ80mm	6000-9000mm
Hot rolled bar	Φ16-Φ310mm	6000-9000mm
Hot forged bar	Φ100-Φ1200mm	3000-5800mm
Hot rolled plate/sheet	T:3-200mm; W:1500-2500mm	2000-5800mm
Hot Forged block	T: 80-800mm; W: 100-2500mm	2000-5800mm

Tolerances & Surface Finishes

Surface Finish	Turned	Milled	Grinding(Best)	Polished(Best)	Peeled(Best)	Black Forged	Black Rolled
Tolerance	+0/+3mm	+0/+3mm	+0/+0.05mm	+0/+0.05mm	+0/+0.1mm	+0/+5mm	+0/+1mm
Straighness	1mm/1000mm max.					3mm/1000mm max.

In-Stock

Hot Rolled Bar Sizes:

• 20, 22, 25, 28, 30, 32, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120mm

In China, most of clients will use 42CrMo4 instead of 50CrMo4, so the stocks for 50CrMo4 is small.

Key Industry Applications

DIN 50CrMo4 is a versatile alloy steel trusted for critical components where high strength, fatigue resistance, and heat stability are non-negotiable. Its applications are tailored to leverage its core mechanical properties across key industries:

1. Automotive Manufacturing

• Powertrain: Crankshafts, camshafts, and drive shafts (high fatigue resistance: ≥30J impact value at RT prevents cyclic load cracking)

• Suspension: Torsion bars, connecting rods, and universal joints (HRC 28-32 hardness absorbs road vibrations without deformation)

• Differentials: Gear sets and axle shafts (flame-hardened surfaces up to HRC 58 resist wear from constant meshing)

2. Heavy Machinery & Construction

• Hydraulic Systems: High-pressure cylinders and piston rods (700Mpa min yield strength prevents bursting under extreme pressure)

• Mining Equipment: Connector pins, gearboxes, and drill bits (0.9-1.2% Cr provides corrosion resistance to dust/moisture)

• Agricultural Machinery: Stamping dies and lifting arms (≥13% elongation for large sizes resists bending/cracking)

3. Aerospace & Defense

• Landing Gear: Struts and brackets (1100-1300Mpa tensile strength for small sizes supports aircraft weight during takeoff/landing)

• Engine Components: High-strength fasteners and casings (QT-treated HRC 28-32 maintains clamping force at high temperatures)

• Missile/Defense Parts: Structural components (high strength-to-weight ratio and impact resistance)

4. Oil & Gas Industry

• Upstream: Drill pipe joints and wellhead equipment (0.15-0.30% Mo enhances heat resistance for high-temperature drilling fluids)

• Downstream: Valves, flanges, and pipeline connectors (low P/S content ≤0.025%/≤0.035% avoids brittleness in cold offshore conditions)

• Refining: Furnace tubes and heat exchangers (heat stability and oxidation resistance)

Grade Comparison: 50CrMo4 1.7228 vs. Common Alloy Steels

Clients frequently compare DIN 50CrMo4 1.7228 with other Cr-Mo steels (e.g., 42CrMo4) and high-carbon steels. Below is a side-by-side comparison of key properties and use cases to guide material selection:

50CrMo4 (1.7228) vs. 42CrMo4 (1.7225)

Aspect	DIN 50CrMo4 1.7228	DIN 42CrMo4 1.7225	Key Takeaway
Carbon Content	0.46-0.54%	0.38-0.45%	50CrMo4 has higher carbon for superior strength/hardness
Molybdenum Range	0.15-0.30%	0.15-0.25%	50CrMo4 offers better heat resistance
Max Tensile Strength	1300Mpa	1100Mpa	50CrMo4 is ideal for high-load applications
Max Hardness (HRC)	58	55	50CrMo4 has superior surface wear resistance
Primary Applications	Crankshafts, landing gear, drill pipes	Brackets, axles, general structural parts	42CrMo4 is more cost-effective for low/medium-stress use cases

AISI 4150 vs. AISI 4140

• AISI 4140 features a lower carbon content (0.38-0.43%) than AISI 4150, resulting in lower tensile strength (max 1000Mpa) and hardness (max HRC 50).

• AISI 4150 is the preferred choice for high-stress applications, while AISI 4140 is used for general engineering parts with moderate load requirements.

50CrMo4 1.7228 vs. 40Cr (GB/T 3077)

• 40Cr is a low-alloy steel with no molybdenum, leading to poor heat resistance and hardenability compared to 50CrMo4.

• 50CrMo4 outperforms 40Cr in high-temperature and fatigue-prone applications, with 30% higher tensile strength after heat treatment.

FAQ

Q1:  Can AISI 4150 / DIN 50CrMo4 1.7228 be welded?

A1: Weldability is poor due to its high carbon content (0.46-0.54%)—above the 0.25% threshold where weld cracking risk rises significantly. However, welding is possible with strict pre- and post-weld treatments:

• Preheating: Heat base metal to 200-300℃ to reduce thermal stress

• Consumables: Use low-hydrogen electrodes (e.g., E8018-B2) to avoid hydrogen-induced cracking

• Post-Weld Heat Treatment (PWHT): Temper at 600-650℃ to soften the heat-affected zone (HAZ) and restore toughness

Q2: What quality certifications are provided with shipments?

A2: All products come with EN 10204 3.1 certificates (material test reports) including:

• Chemical composition analysis (OES testing)

• Mechanical property data (tensile, yield, elongation, impact)

• Hardness test results (HB/HRC)

• Surface inspection reports (UT/visual testing)

Custom testing (e.g., NDT, corrosion resistance, fatigue testing) is available upon request.

Q3: How to select the right heat treatment for my application?

A3: The right heat treatment for DIN 50CrMo4 (1.7228) depends entirely on your component's final performance requirements. Here is a guideline based on common objectives:

• Pre-machining: Soft annealing (+A) (HB ≤248) to minimize tool wear

• Structural parts (balance of strength/ductility): Quenching & tempering (+QT) (HRC 28-32)

• Surface wear resistance (gear teeth/bearings): QT + flame/induction hardening (HRC 55-58)

• Heavy forgings (deep hardening): +HH grade hardenability with oil quenching

Q4: Does Hunan Qilu Steel provide machining services for these materials?

A4: Yes, we can provide basic machining services such as milling, sawing to length, and turning to produce rough-machined components or cut your material to exact specifications, saving you time in your initial processing stages. Please inquire with your requirements.

Contact Us: For custom size inquiries, technical support, or to request a detailed datasheet, contact our sales team.