AISI 4145H Modified Alloy Steel: High Tensile Strength and Superior Hardenability
AISI 4145H MODIFIED / UNS G41450
MATERIAL DESCRIPTION
4145H MOD MATERIAL DESCRIPTION: 4145H MOD is an upgraded type of AISI 4145, commonly used in the high tensile steel for drilling tools such as drill collars and shafts. This alloy steel is suitable for downhole drilling applications due to its high strength and wear resistance. The steel grade contains chromium molybdenum and higher carbon content, which provide excellent hardenability and impact resistance. With a specified minimum yield strength of 110 ksi, 4145H MOD is known for its good ductility and shock resistance in downhole conditions. It is often supplied in the quenched and tempered condition to maximize its strength characteristics, making it suitable for larger diameters and heavy-duty drilling equipment. The material is commonly used in the oil and gas industry for its exceptional performance in high temperature and high-pressure environments.
Applications
4145H MOD Applications involve the use of an upgraded type of AISI 4140 alloy steel, known as 4145 mod. This high tensile steel is commonly used in the high strength drilling tools such as subs, due to its good ductility and shock resistance. The steel grade is suitable for downhole applications, as it can withstand high temperatures and wear. The low alloy steel composition includes higher carbon content, making it suitable for larger diameters and higher impact requirements in the engineering field. With added molybdenum and chromium, the steel has good hardenability and can be quenched and tempered to increase its strength and wear resistance. It is commonly used in the oil and gas industry for drilling tools due to its high tensile strength and yield of up to 125 ksi.
When it comes to drill collars, the 4145H MOD steel is a preferred choice for its resistance to cracking and its ability to withstand downhole conditions. The steel’s alloy composition enhances its wear and temperature resistance, making it ideal for the demanding environment of oil and gas drilling. The steel is commonly supplied in the quenched and tempered condition, ready for use in various drilling applications. Its alloy steel characteristics make it suitable for larger gear shafts, connecting rods, and other critical components that require high tensile strength and impact resistance. The AISI 4140 and 4145 mod steel grades are widely used in the oil and gas industry for their superior properties and suitability for harsh downhole conditions.
Heat Treatment
4145H MOD Heat Treatment involves treating a molybdenum low alloy steel to achieve a high strength condition suitable for various applications. This heat treatment process includes soaking the steel at a max temperature range to improve hardenability, followed by a rapid cool to achieve a hardness level of 30-36hrc. The resulting high tensile steel has good shock resistance and wear, making it suitable for downhole drilling tools, bolts etc, and x-overs. However, its susceptibility to cracking must be taken into consideration. The chinese api standard has ruling on the heat treatment of this steel, except for specific requirements. With a commitment to ensuring the steel’s high tensile strength and ductility, the 4145H MOD heat treatment process is essential for meeting industry standards.
Forging:
Preheat the steel carefully, then raise the temperature to 1150-1200°C for forging. Do not forge below 850°C. AISI 4145 has good forging characteristics but care must be taken when cooling the steel due to its susceptibility to cracking.
Annealing:
Heat the steel slowly to 800-850°C and allow enough time for the steel to be thoroughly heated. Cool slowly in the furnace to 480°C followed by air cooling.
Harding:
AISI 4145 steel is usually supplied ready heat treated to 30-36HRc. If further heat treatment is required annealed AISI 4145 should be heated slowly to 840-875°C and after adequate soaking at this temperature quench in oil. Temper as soon as the tools reach room temperature.
Tempering:
Heat carefully to a suitable temperature selected by reference to a tempering chart or table (usually between 550-700°C, soak at the temperature for 2 hours per 25mm of ruling section, then allow to cool in air. Tempering between 250-375°C is not advised as tempering within this range will seriously reduce the impact values of this steel.
Weldability
4145H MOD Weldability is a crucial factor to consider when working with this high tensile steel. With a carbon content of 0.35, this steel has good ductility, making it suitable for various welding applications. However, the weldability of 4145H MOD is somewhat limited due to its susceptibility to cracking. It is important to carefully control the welding process and use appropriate techniques to ensure strong and durable welds. Despite these challenges, 4145H MOD is commonly used in industries where high strength and toughness are required, such as in the construction of heavy machinery, oil pipelines, and military vehicles. Stock availability of this steel may vary depending on the section and size required, but with proper handling and welding procedures, it can be a reliable choice for demanding applications.
Chemical Composition
| Min. % | Max % | |
| Carbon | 0.42 | 0.49 |
| Silicon | 0.15 | 0.35 |
| Manganese | 0.65 | 1.1 |
| Chromium | 0.75 | 1.2 |
| Molybdenum | 0.15 | 0.25 |
| Phosphorous | 0 | 0.035 |
| Sulphur | 0 | 0.04 |
| Nickel | 0 | 0.25 |
| Copper | 0 | 0.35 |
Reference Standards
| International | API Spec 7 |
| USA | SAE J1268, UNS H41450, ASTM A304 |
Mechanical Properties
| Yield Strength
R p0.2(MPa) |
Tensile Strength
R m(MPa) |
Elongation δ5 (%): | Reduction
of area ψ (%): |
Impact energy
Akv (J): |
Impact toughness
value αkv (J/cm2) |
Hardness |
| ≥ 758(85) | ≥ 965(95) | ≥ 14.5 | ≥ 45 | ≥ 41 | ≥ 39(4) | ≥ 285 HB |
Advantages:
4145H MOD Advantages: The tensile steel has good ductility which makes it ideal for various industrial applications. One of the key benefits of 4145H MOD is its superior strength, making it a popular choice for parts that require high strength and durability. Its high tensile strength allows for the use of thinner sections without sacrificing performance. In addition, the improved hardenability of 4145H MOD ensures that parts can be hardened and tempered to achieve the desired properties. Its versatility and reliability make it a top choice for a wide range of applications.
Quality Inspection
4145H MOD Quality Inspection
The 4145H MOD quality inspection process rigorously evaluates the integrity and performance of each bar produced. This ensures that the final product meets industry standards and customer expectations. Applications include aerospace components, oilfield equipment, and high-stress engineering structures. Every detail is carefully click checked and verified to guarantee the highest level of quality and reliability.
Throughout the inspection process, experienced technicians meticulously examine each bar to identify any potential defects or irregularities. Any discrepancies are promptly addressed and resolved to maintain the overall quality of the product. Additionally, advanced testing equipment is utilized to ensure that the material properties meet the specified requirements.
PROCESSING
4145H MOD PROCESSING is a specific type of heat treatment process used to improve the mechanical properties of steel. This process involves modifying the microstructure of the steel through a combination of heating and cooling. The goal of 4145H MOD PROCESSING is to increase the strength, toughness, and hardness of the steel, making it more suitable for demanding applications such as aerospace or automotive components.
One key component of the 4145H MOD PROCESSING is the quenching step, where the steel is rapidly cooled after being heated to a specific temperature. This rapid cooling helps to lock in the desired properties of the steel, resulting in a stronger and more durable end product. Additionally, the steel may undergo tempering after quenching to further refine its properties and reduce any brittleness that may have developed during the quenching process.
Equivalent Grade:
- EN 1.7225
- ASTM A255
- UNS G41450
- AISI 4145H Modified
1.1% Chromium-Molybdenum Through Hardening Steel
1.1% Chromium-Molybdenum Through Hardening Steel is a type of steel alloy that contains a combination of chromium and molybdenum elements. This specific composition allows the steel to have excellent hardenability and wear resistance properties. When properly heat treated, the steel can achieve high levels of hardness and toughness throughout its entire structure.
The presence of chromium enhances the steel’s corrosion resistance, making it suitable for applications that require exposure to harsh environments or chemicals. On the other hand, molybdenum contributes to the steel’s strength and high-temperature performance. This makes 1.1% Chromium-Molybdenum Through Hardening Steel a popular choice in industries such as aerospace, automotive, and tool manufacturing.
Due to its through-hardening capabilities, this type of steel is often used in components that need to withstand heavy loads, impact, and abrasive wear. Whether it’s gears, shafts, or cutting tools, 1.1% Chromium-Molybdenum Through Hardening Steel offers the necessary combination of hardness and toughness to ensure reliable performance in demanding applications.
What is equivalent to 4145H steel?
4145H steel is a type of alloy steel that is commonly used in the oil and gas industry for the manufacturing of drill collars, pipes, and other equipment that require high strength and toughness. It is known for its excellent hardenability and impact strength, making it suitable for harsh environments and heavy-duty applications. In terms of equivalent grades, 4145H steel is similar to ASTM A320 Grade L80 and API 5CT P110 steels. These grades have similar chemical compositions and mechanical properties, making them interchangeable in many applications. Additionally, 4145H steel can also be compared to SAE 4140 and SAE 4145 steels, which are commonly used in the automotive and aerospace industries due to their high strength and versatility.
What is the difference between 4140 and 4145?
4140 and 4145 are both steel alloys commonly used in industrial applications due to their high strength and toughness properties. However, there are some key differences between the two materials. One of the main distinctions is their carbon content. 4140 contains approximately 0.40% carbon, while 4145 contains around 0.45% carbon. This difference in carbon content can affect the hardness and machinability of the steel. Additionally, 4145 typically contains higher amounts of other alloying elements such as molybdenum and chromium, making it more suitable for applications requiring higher strength and resistance to wear. On the other hand, 4140 is more versatile and commonly used in a wide range of applications where high strength and impact resistance are required.
What is AISI 4145 H material?
AISI 4145 H material is a low alloy steel with high yield strength and excellent toughness. This material is commonly used in the oil and gas industry for components such as drill collars, stabilizers, and subs. The “H” in AISI 4145 H stands for heat-treated, indicating that the material has been subjected to a specific heat treatment process to enhance its mechanical properties. This steel grade is known for its exceptional resistance to wear, corrosion, and abrasion, making it ideal for harsh operating conditions in drilling and completion operations. AISI 4145 H material meets the requirements of the American Iron and Steel Institute (AISI) and is commonly supplied in the quenched and tempered condition. Overall, AISI 4145 H material is a reliable and durable option for demanding applications in the oil and gas industry.
What is the hardness of 4145 steel?
4145 steel is a low alloy steel known for its high strength and toughness. It has a hardness rating of 22-32 HRC, making it suitable for demanding applications where resistance to wear and abrasion is important. The combination of chromium, molybdenum, and manganese in its composition contributes to its hardness and ability to withstand heavy loads. This steel is often used in the manufacturing of components for the oil and gas industry, such as drill collars and shafts, where high strength and reliability are required.
What is 4145 steel used for?
4145 steel is a high-strength, low-alloy steel that is commonly used in the oil and gas industry. Its unique combination of strength, toughness, and hardness makes it ideal for applications where high stress and wear resistance are required. One of the primary uses of 4145 steel is in the manufacturing of downhole drilling tools, such as drill collars and drill pipes. These tools are subjected to extreme conditions, including high temperatures, pressures, and abrasive materials, making 4145 steel an excellent choice due to its ability to withstand such harsh environments.
In addition to drilling tools, 4145 steel is also used in the production of components for heavy machinery, such as gears, shafts, and sprockets. Its high tensile strength and impact resistance make it well-suited for these applications, where durability and reliability are essential.