42CrMo Castings

42CrMo Castings Composition and Characteristics

Chemical composition affects the overall performance, hardenability and mechanical properties of the casting. For example, chromium and molybdenum elements can improve hardenability. Carbon affects strength and hardness. 42CrMo castings have a unique chemical composition. It has excellent mechanical properties.

Chemical composition

Element	C	Si	Mn	Cr	Mo	P	S
Composition(%)	0.38-0.45	0.17-0.37	0.50-0.80	0.90-1.20	0.15-0.25	≤0.035	≤0.035

Low phosphorus and sulfur content improves the purity and toughness of 42CrMo alloy steel castings.

Characteristics

Key Properties and Characteristics	Detailed Description
High Strength	Possesses good overall strength, suitable for demanding applications.
Hardenability	Can be effectively hardened through heat treatment to enhance strength and wear resistance.
Toughness	Exhibits good toughness, enabling it to withstand impact and dynamic loads.
Wear Resistance	Demonstrates excellent wear resistance, making it suitable for parts subject to friction and abrasion.
Creep Strength at High Temperatures	Shows good creep strength and endurance strength under high-temperature conditions.
Allowable Stress	The allowable stress typically ranges from 186 to 310 MPa.
Yield Point	The yield point is approximately 930 MPa.

42CrMo Castings Methods and QC

42CrMo is often cast using methods like investment casting (also known as lost wax casting) and sand casting. Investment casting is known for producing parts with intricate shapes and high dimensional accuracy, while sand casting is suitable for larger parts and offers a lower initial tooling cost. 

I. Analysis of Precise Control over Environmental Factors (Temperature, Humidity) in Casting

1. Significance of Control

• Temperature Control: 42CrMo is a medium-carbon alloy structural steel. Its melting temperature strictly is controlled at 1520-1560℃. If the casting temperature is lower than 1480℃, the fluidity of molten metal decreases. Prone to defects such as cold shuts and incomplete filling.
• Humidity Control: In sand casting, the humidity of molding sand must be maintained at 4%-6%. Excessive humidity causes air holes and sand adhesion in castings. While insufficient humidity reduces sand strength, leading to sand holes.

2. Practical Examples of Control

• JC Casting’s Practices:
  • Equipped with intelligent temperature-controlled melting furnaces (accuracy ±5℃), real-time monitoring of furnace temperature curves via PLC systems to ensure uniform composition of carbon, chromium, and molybdenum elements in 42CrMo during melting.
  • The casting workshop is installed with a constant temperature and humidity system. Its temperature is controlled at 25±2℃, humidity 50±5%. It can prevent environmental fluctuations from affecting sand mold strength and the solidification process of molten metal.
  • Infrared thermal imagers are used to monitor the casting process. Ensuring the casting temperature stabilizes at 1480-1520℃ to prevent internal stress concentration in castings due to temperature fluctuations.

II. Analysis of Diversity in Product Specifications and Customization Options

1. Scope of Specifications

• Dimensions and Weight:
  • Casting size: Minimum diameter 10mm, maximum length 3000mm (e.g., long shaft parts);
  • Weight range: 0.5kg-500kg per piece (e.g., gearbox housings, high-pressure valve casings).
• Surface Treatments:
  • Anti-corrosion treatments: Galvanizing (zinc layer thickness 8-12μm), chrome plating (hard chrome layer thickness 50-100μm);
  • Protective coatings: Epoxy resin painting (dry film thickness 100-200μm), blackening treatment (oxide film thickness 1-3μm).

2. Customization Examples

• Automotive Industry Customization: Produced 42CrMo differential housings for an OEM, requiring:
  • Dimensions: φ280mm×150mm, weight 25kg;
  • Surface treatment: Galvanizing + salt spray-resistant coating (passing 500-hour salt spray test);
  • Special requirement: Internal oil passages must pass fluorescent penetrant inspection (sensitivity level 2).
• Oil & Gas Industry Customization: Manufactured valve covers for API 6A standard valves, with specifications:
  • Dimensions: DN150 (6 inches), pressure class Class 1500;
  • Weight: 180kg, surface subjected to wear-resistant surfacing (hard alloy layer thickness 3-5mm);
  • Testing standard: Ultrasonic testing (ASTM A388-16, Grade I qualification).

Applications of 42CrMo Castings

42CrMo steel has a wide range of uses. It is used in a wide variety of industrial manufacturing applications due to its excellent strength and toughness. Here is a breakdown of its common uses:

Application Field	Specific Components
Construction	Crane parts, bulldozer components
Automotive	Axles, gears, suspension parts
Mining	Drill rods, crusher parts
Oil & Gas	Valves, pipelines
Manufacturing	Gears, shafts, hydraulic components
Heavy Machinery	Large gears, shafts, and other high-strength durable components
Agricultural Machinery	Components for various agricultural equipment

Comparison with other materials:

40Cr VS 42CrMo

40Cr is also a structural steel. 42CrMo generally offers better mechanical properties. Especially in high-load and high-strength applications. 42CrMo exhibits better strength, wear resistance, and toughness compared to 40Cr. 

42CrMo4 VS 42CrMo

42CrMo4 is the European designation for this steel grade. But 4140 is the American designation. They are essentially the same steel grade, belonging to the chromium-molybdenum family. 

Choose JC Casting as your 42CrMo Castings Supplier

As a leading 42CrMo castings manufacturer, JC Casting offers precision casting and sand casting solutions. The company’s production base covers an area of 100,000 square meters, including 2 casting workshops and 1 CNC machining workshop.

To ensure precise control during the melting and molding processes of 42CrMo materials, JC Casting has established a comprehensive testing laboratory. It is equipped with advanced testing instruments such as spectrometers, ultrasonic flaw detectors, and smoke testing equipment. The company strictly adheres to the ISO 9001 quality management system standards and has obtained certifications including ISO/TS 16949 for the automotive industry quality management system and API 6A for the oil and gas industry. These stringent quality controls guarantee the stable and reliable performance of its products.