SES N 3104 Low Alloy Steel Specification

Developed by Suzuki Motor Corporation as part of metallic material standards, the “SES N 3104 Low Alloy Steel Specification” is a technical standard that defines the chemical composition, mechanical properties, manufacturing methods, and quality requirements of low alloy steel materials used in the automotive industry.

Low-alloy steels are steels in which the total alloying element content generally does not exceed 5 percent. These steels contain only small amounts of alloying elements to improve their mechanical and chemical properties compared to carbon steel. Typical alloying elements include chromium, molybdenum, nickel, vanadium, copper, and manganese. The aim is to give the material higher strength, toughness, hardenability, and wear resistance.

In general, the SES N 3104 standard covers the following requirements:

• Chemical composition: The boundaries of elements such as carbon, manganese, chromium, molybdenum, and nickel.
• Mechanical properties:
• Yield strength
• Tensile strength
• Elongation
• Hardness
• Heat treatment requirements:
• Normalization
• Quenching
• Tempering
• Testing and validation:
• Tensile test
• Impact test (Charpy)
• Hardness measurement
• Production requirements:
• Rolling conditions
• Surface quality
• Tolerances

The purpose of using this standard in the automotive industry is as follows:

• It ensures that the same part is produced with the same quality by different suppliers.
• It guarantees safety in critical components.
• It standardizes material selection.

Typical chemical content ranges (approximate values) for low-alloy steels are as follows:

• Carbon: 0,1-0,3%
• Manganese: 0,5-1,5%
• Chromium: 0,3-1,0%
• Molybdenum: 0,1-0,5%
• Nickel: 0,2-0,5%
• Silicon: 0,2-0,5%

Since each steel standard and intended use is different, the values ​​may vary.

Low-alloy steels generally have the following properties:

• Yield strength: 250-600 MPa
• Tensile strength: 400-800 MPa
• Lengthening: 15-25 percent
• Impact resistance (Charpy, 20 degrees): 30-80 J

Properties can be further improved through heat treatment (e.g., annealing, carburization, tempering).

Low-alloy steels are used in applications requiring high strength and toughness:

• Automotive parts (chassis, axle, shaft)
• Machine parts (gears, shafts, pins)
• Pressure vessels and pipes
• Bridge and building constructions

Examples of standards for low-alloy steels include:

• SAE 4140: Chromium-molybdenum alloy steel: Used in high-strength shafts and gears.
• EN 1.7225 (42CrMo4): Chromium-molybdenum steel: Used in machine parts.
• S355JR (EN 10025): Structural low-alloy steel: Used in bridge and building construction.

In short, low-alloy steels offer higher strength and toughness than carbon steel. They contain small amounts of alloying elements (less than 5 percent). They are widely used in the automotive, construction, and machinery industries.

Low-alloy steels are one of the most commonly used materials in the automotive industry because they provide high strength, toughness, and cost-effectiveness. Despite containing small amounts of alloying elements (such as chromium, molybdenum, nickel, and vanadium), they offer significant performance advantages.

The main areas of application in the automotive industry are as follows:

• Chassis and load-bearing structures: Low-alloy steels are used in the main load-bearing frame of vehicles. Their applications include:
• Chassis
• Side beams
• Collision energy absorbing regions

It is used for the following reasons:

• High yield strength
• Good impact resistance (collision safety)
• Weight reduction through thinner sections.
• Powertrain systems: Their applications include:
• crankshafts
• Camshafts
• Shafts
• Differential components

It is used for the following reasons:

• High fatigue resistance
• Good wear resistance.
• Hardness can be increased by heat treatment.
• Gears and mechanical parts: Their applications include:
• Gearbox gears
• Planetary gear systems
• Reduction systems

It is used for the following reasons:

• Surface hardness is increased through cementation and tempering.
• The internal structure remains robust and resistant to breakage.
• Suspension and drivetrain: Areas of application include:
• Bows
• Swing arms
• axles

It is used for the following reasons:

• High elasticity and fatigue resistance.
• Ability to operate under continuous load.
• Fasteners: Their areas of application are as follows:
• bolts
• Nuts
• pins

It is used for the following reasons:

• High tensile strength
• Reliable clamping force.
• Different strength classes can be produced through heat treatment.
• Exhaust and high-temperature components: Some low-alloy steels have been developed to withstand high temperatures. Their applications include:
• Exhaust manifolds
• Turbo components

It is used for the following reasons:

• heat resistance
• Oxidation resistance
• Safety components: Their areas of application are as follows:
• Collision bars
• Door interior reinforcement elements

It is used for the following reasons:

• Energy absorption capacity
• Controlled deformation

In general, the reasons for using the SES N 3104 standard in the automotive industry are as follows:

• High strength-to-weight ratio.
• Good weldability
• Features customizable through heat treatment.
• Cost-effective
• Suitable for mass production

In conclusion, the SES N 3104 standard is considered necessary by the automotive industry because it includes criteria in the following areas:

• It ensures consistency: Every manufacturer produces the same quality.
• It provides safety: It reduces the risk of failure in critical components.
• International compatibility: This allows the same material to be used in different countries.
• It facilitates mass production: This is a critical issue, especially in sectors such as the automotive industry.

Low-alloy steels are widely used in the automotive industry for applications requiring structural strength (such as chassis and body), load-bearing and rotating parts (such as crankshafts, gears, and shafts), and safety components.

For many years, our organization, with its competent and experienced team, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services compliant with the SES N 3104 standard.