Available Shapes
AISI 4145 Alloy Steel
AISI 4145 is a chromium molybdenum alloy steel grade widely used in the oil and gas sectors.
Similar to AISI 4140 but with a higher carbon content. 4145 is more popular in larger diameters due to its increased strength and hardenability. AISI 4145 is commonly supplied quenched and tempered with a hardness of between 30 to 36HRc.
AISI 4145H is a chromium – molybdenum low alloy tempered steel.
AISI 4145H has improved hardenability and is more is commonly used in the high strength condition with min.110 KSI yield. Similar to AISI 4140 but with a higher carbon content. 4145 is more popular in larger diameters due to its increased strength and hardenability.
AISI 4145 is a chromium molybdenum alloy steel grade widely used in the oil and gas sectors.
Similar to AISI 4140 but with a higher carbon content. 4145 is more popular in larger diameters due to its increased strength and hardenability. AISI 4145 is commonly supplied quenched and tempered with a hardness of between 30 to 36HRc.
AISI 4145H is a chromium – molybdenum low alloy tempered steel.
AISI 4145H has improved hardenability and is more is commonly used in the high strength condition with min.110 KSI yield. Similar to AISI 4140 but with a higher carbon content. 4145 is more popular in larger diameters due to its increased strength and hardenability.
Applications
Analysis
Forging
Annealing
Stress Relieving
Hardening
Tampering
Applications
AISI 4145 is commonly used for a variety of applications in the oil and gas sector. Used often for the manufacture of down hole drilling tools such as drill collars. Other applications include gears, shafts for hydraulic presses, rolls for paper mills, pump shafts and tool holders. AISI 4145H is a low alloy steel suitable for downhole drilling tools such as subs, x-overs, drill collars, pup-joints and fishing tools. General engineering applications include components exposed to heavy strain, such as shafts, gear, bolts etc. AISI 4145H can also be used in hardened condition as machine parts exposed to heavy wear.
Analysis
| Carbon | 0.43-0.49% | Chromium | 0.80-1.10% |
| Manganese | 0.85-1.10% | Molybdenum | 0.15-0.25% |
| Silicon | 0.10-0.35% | Phosphorous | 0.035% max |
| Nickel | 0.25% max | Sulphur | 0.040% max |
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.
Stress Relieving
When parts are heavily machined, ground or otherwise subject to cold work, stress relieving will be beneficial prior to hardening.
Hardening
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.
Tampering
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.
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