AISI 4118H Steel

AISI 4118H Steel Chemical Composition

 

Element	Content (%)
Iron, Fe	97.7-98.49
Manganese, Mn	0.70-0.90
Chromium, Cr	0.40-0.60
Carbon, C	0.18-0.230
Silicon, Si	0.15-0.35
Molybdenum, Mo	0.080-0.15
Sulfur, S	0.040
Phosphorous, P	0.035

 

Physical Properties

 

Properties	Metric	Imperial
Density	7.85 g/cm3	0.284 lb/in³

 

Mechanical Properties

 

Properties	Metric	Imperial
Tensile strength	517 MPa	75000 psi
Yield strength	365 MPa	52900 psi
Bulk modulus (typical for steel)	140 GPa	20300 ksi
Shear modulus (typical for steel)	80.0 GPa	11600 ksi
Elastic modulus	190-210 GPa	27557-30458 ksi
Poisson's ratio	0.27-0.30	0.27-0.30
Elongation at break (in 50 mm)	33.00%	33.00%
Reduction of area	63.70%	63.70%
Hardness, Brinell	137	137
Hardness, Knoop (converted from Brinell hardness)	156	156
Hardness, Rockwell B (converted from Brinell hardness)	75	75
Hardness, Vickers (converted from Brinell hardness)	143	143
Machinability (hot rolled and cold drawn, based on 100 machinability for AISI 1212 steel)	60	60

 

First and foremost, strict quality control should be implemented throughout the production process. This starts with the selection of high-quality raw materials. Ensure that the AISI 4118H steel used meets the required specifications in terms of chemical composition and mechanical properties. Any deviations in the raw material can lead to variations in the final dimensions of the components.

 

During machining operations, use precision tools and equipment. Modern CNC machines can offer high levels of accuracy and repeatability. Program the machines accurately to ensure that the cutting parameters, such as feed rate, spindle speed, and depth of cut, are optimized for the specific material and part geometry. Regularly calibrate and maintain the machining equipment to ensure consistent performance.

 

Heat treatment is often a critical step in the processing of AISI 4118H steel. Precise control of the heat treatment parameters, including temperature, time, and cooling rate, is essential to minimize dimensional changes. Use proper fixtures and quenching methods to ensure uniform cooling and prevent distortion. After heat treatment, perform dimensional inspections to verify that the parts still meet the required tolerances.

 

In addition to machining and heat treatment, metrology plays a vital role in ensuring dimensional accuracy. Employ accurate measuring instruments, such as micrometers, calipers, and coordinate measuring machines (CMMs). Train operators to use these instruments correctly and perform regular calibration to ensure their accuracy. Conduct frequent inspections at different stages of production to catch any dimensional deviations early on and take corrective actions.

 

Finally, establish a quality management system that includes documentation and traceability. Keep records of all production steps, including raw material procurement, machining parameters, heat treatment processes, and inspection results. This allows for easy identification of potential issues and helps in implementing continuous improvement measures.

 

By implementing these measures, manufacturers can ensure the dimensional accuracy of components made from AISI 4118H steel, leading to reliable and high-quality products.

 

 

Hot Tags: aisi 4118h steel, China aisi 4118h steel suppliers, factory, SNCM220, SUS410, C4430, CuZn40, N08810, S235J0