1075 Steel: Properties and Key Applications

1075 steel is classified as a medium-carbon steel, primarily composed of iron with a carbon content of approximately 0.75%. This grade falls within the AISI/SAE classification system, which categorizes steels based on their carbon content and alloying elements. The primary alloying element in 1075 steel is carbon, which significantly influences its hardness, strength, and wear resistance.

Comprehensive Overview

1075 steel is known for its excellent hardness and wear resistance, making it a popular choice for applications requiring high strength and durability. The medium carbon content allows for good hardenability, which is the ability to harden the steel through heat treatment processes. This steel grade is often used in the manufacturing of tools, blades, and springs, where high tensile strength and resistance to deformation are critical.

Advantages of 1075 Steel:
- High Hardness: The carbon content contributes to a high hardness level, making it suitable for cutting tools and wear-resistant applications.
- Good Wear Resistance: Its ability to withstand wear makes it ideal for applications like knife blades and springs.
- Versatile Heat Treatment: 1075 steel can be heat-treated to achieve desired mechanical properties, enhancing its performance in various applications.

Limitations of 1075 Steel:
- Brittleness: Higher carbon content can lead to increased brittleness, especially if not properly heat-treated.
- Limited Corrosion Resistance: Compared to stainless steels, 1075 steel has lower resistance to corrosion, which may limit its use in certain environments.
- Difficult Machinability: The hardness of 1075 steel can make it challenging to machine, requiring specialized tools and techniques.

Historically, 1075 steel has been utilized in various applications, particularly in the production of knives and tools, due to its balance of hardness and toughness. Its market position is well-established, particularly among manufacturers of high-performance cutting tools.

Alternative Names, Standards, and Equivalents

Standard Organization	Designation/Grade	Country/Region of Origin	Notes/Remarks
UNS	G10750	USA	Closest equivalent to AISI 1075
AISI/SAE	1075	USA	Commonly used for tool manufacturing
ASTM	A681	USA	Specification for tool steels
EN	C75	Europe	Similar properties but may have different applications
JIS	S75C	Japan	Minor compositional differences to be aware of

The table above outlines various standards and equivalents for 1075 steel. Notably, while grades like C75 and S75C may have similar mechanical properties, they can differ in their specific applications and heat treatment processes, which can affect performance in practical use.

Key Properties

Chemical Composition

Element (Symbol and Name)	Percentage Range (%)
C (Carbon)	0.70 - 0.80
Mn (Manganese)	0.60 - 0.90
Si (Silicon)	0.15 - 0.40
P (Phosphorus)	≤ 0.04
S (Sulfur)	≤ 0.05

The primary alloying elements in 1075 steel include carbon, manganese, and silicon. Carbon is crucial for increasing hardness and strength, while manganese enhances hardenability and toughness. Silicon contributes to deoxidation during steelmaking and can improve strength and hardness.

Mechanical Properties

Property	Condition/Temper	Test Temperature	Typical Value/Range (Metric)	Typical Value/Range (Imperial)	Reference Standard for Test Method
Tensile Strength	Quenched & Tempered	Room Temp	600 - 850 MPa	87 - 123 ksi	ASTM E8
Yield Strength (0.2% offset)	Quenched & Tempered	Room Temp	400 - 600 MPa	58 - 87 ksi	ASTM E8
Elongation	Quenched & Tempered	Room Temp	10 - 15%	10 - 15%	ASTM E8
Hardness (Rockwell C)	Quenched & Tempered	Room Temp	50 - 60 HRC	50 - 60 HRC	ASTM E18
Impact Strength	Quenched & Tempered	-20 °C	20 - 30 J	15 - 22 ft-lbf	ASTM E23

The mechanical properties of 1075 steel make it suitable for applications requiring high strength and toughness. The combination of high tensile and yield strength, along with reasonable elongation, allows for effective performance under mechanical loading. The hardness values indicate its suitability for wear-resistant applications.

Physical Properties

Property	Condition/Temperature	Value (Metric)	Value (Imperial)
Density	Room Temp	7.85 g/cm³	0.284 lb/in³
Melting Point	-	1425 - 1540 °C	2600 - 2800 °F
Thermal Conductivity	Room Temp	45 W/m·K	31 BTU·in/h·ft²·°F
Specific Heat Capacity	Room Temp	0.46 kJ/kg·K	0.11 BTU/lb·°F
Electrical Resistivity	Room Temp	0.0006 Ω·m	0.00001 Ω·in

The density and melting point of 1075 steel indicate its robustness and suitability for high-temperature applications. The thermal conductivity and specific heat capacity are important for applications involving thermal cycling, as they affect how the material behaves under temperature changes.

Corrosion Resistance

Corrosive Agent	Concentration (%)	Temperature (°C)	Resistance Rating	Notes
Chlorides	3-5%	25 °C	Fair	Risk of pitting corrosion
Acids	10%	20 °C	Poor	Not recommended for use
Alkaline Solutions	5%	30 °C	Fair	Limited resistance

1075 steel exhibits limited corrosion resistance, particularly in environments with chlorides and acidic conditions. Its susceptibility to pitting corrosion in chloride environments is a significant concern, making it less suitable for marine applications. Compared to stainless steels, such as 304 or 316, 1075 steel's corrosion resistance is notably inferior, which can be a critical factor in material selection for specific applications.

Heat Resistance

Property/Limit	Temperature (°C)	Temperature (°F)	Remarks
Max Continuous Service Temp	300 °C	572 °F	Suitable for short-term exposure
Max Intermittent Service Temp	400 °C	752 °F	Limited oxidation resistance
Scaling Temperature	600 °C	1112 °F	Risk of scaling at high temps

At elevated temperatures, 1075 steel can maintain its strength and hardness up to a certain limit. However, prolonged exposure to high temperatures may lead to oxidation and scaling, which can compromise its mechanical properties. Proper heat treatment and surface protection can mitigate these issues.

Fabrication Properties

Weldability

Welding Process	Recommended Filler Metal (AWS Classification)	Typical Shielding Gas/Flux	Notes
MIG	ER70S-6	Argon + CO2	Preheat recommended
TIG	ER70S-2	Argon	Requires careful control
Stick	E7018	N/A	Post-weld heat treatment needed

1075 steel can be welded using various methods, but preheating is often recommended to reduce the risk of cracking. Post-weld heat treatment can also enhance the toughness of the welds. Careful selection of filler metals and shielding gases is crucial to ensure strong and durable welds.

Machinability

Machining Parameter	1075 Steel	AISI 1212	Notes/Tips
Relative Machinability Index	60	100	Requires high-speed tooling
Typical Cutting Speed	30-50 m/min	60-80 m/min	Use carbide tools for best results

The machinability of 1075 steel is moderate, requiring specific tooling and cutting speeds to achieve optimal results. The hardness of the material can lead to increased tool wear, necessitating the use of high-speed steel or carbide tools.

Formability

1075 steel exhibits limited formability due to its higher carbon content, which can lead to brittleness during cold forming processes. Hot forming is more suitable, allowing for better shaping without compromising the material's integrity. The work hardening effect should be considered when designing parts that require bending or shaping.

Heat Treatment

Treatment Process	Temperature Range (°C/°F)	Typical Soaking Time	Cooling Method	Primary Purpose / Expected Result
Annealing	700 - 800 °C / 1292 - 1472 °F	1-2 hours	Air	Softening, improving machinability
Quenching	800 - 900 °C / 1472 - 1652 °F	30 minutes	Oil or Water	Hardening, increasing strength
Tempering	150 - 300 °C / 302 - 572 °F	1 hour	Air	Reducing brittleness, improving toughness

Heat treatment processes significantly affect the microstructure and properties of 1075 steel. Quenching increases hardness, while tempering reduces brittleness, allowing for a balance between strength and toughness. Understanding these transformations is crucial for achieving desired performance characteristics in applications.

Typical Applications and End Uses

Industry/Sector	Specific Application Example	Key Steel Properties Utilized in this Application	Reason for Selection
Tool Manufacturing	Knife Blades	High hardness, wear resistance	Essential for cutting performance
Automotive	Springs	High tensile strength, fatigue resistance	Critical for durability under load
Aerospace	Landing Gear Components	High strength, toughness	Safety and reliability in critical applications

1075 steel is commonly used in applications where high strength and wear resistance are essential. Its properties make it ideal for manufacturing cutting tools, springs, and components in the automotive and aerospace industries. The selection of 1075 steel for these applications is driven by its ability to maintain performance under demanding conditions.

Important Considerations, Selection Criteria, and Further Insights

Feature/Property	1075 Steel	AISI 1080	AISI 4140	Brief Pro/Con or Trade-off Note
Key Mechanical Property	High hardness	Higher hardness	Lower hardness	1075 offers a balance of strength and toughness
Key Corrosion Aspect	Fair	Fair	Good	4140 has better corrosion resistance
Weldability	Moderate	Moderate	Good	4140 is easier to weld with proper techniques
Machinability	Moderate	Poor	Good	4140 is easier to machine than 1075
Formability	Limited	Limited	Good	4140 can be formed more easily
Approx. Relative Cost	Moderate	Moderate	Higher	Cost varies based on alloying elements
Typical Availability	Common	Common	Less common	1075 is widely available for various applications

When selecting 1075 steel, considerations include its mechanical properties, corrosion resistance, and fabrication characteristics. While it offers excellent hardness and wear resistance, its limitations in corrosion resistance and machinability must be weighed against the requirements of the specific application. The cost-effectiveness and availability of 1075 steel make it a popular choice in many industries, but alternative grades may be more suitable depending on the specific needs of the project.