Alloy Structure Steel 4140 |good workability Alloy Structure Steel 4140 steel round bar

AVAILABLE SIZE:

Round bar: Diameter(mm) Max 800mm; Length(mm) Max 12000mm.

Plate: Thickness(mm) Max 800mm; Width(mm) Max 2300mm; Length(mm) Max 12000mm.

Condition: Cold rolled(drawn)≤50mm, Hot rolled≤12-250mm, Hot forged≥50mm.

AISI 4140/DIN 1.7225 Introduction:

AISI 4140 alloy steel is chromium, molybdenum, manganese containing low alloy steel. It has high fatigue strength, abrasion and impact resistance, toughness, and torsional strength.

Fabrication and Heat Treatment:

1. Forging

Preheat the steel carefully, then raise the temperature to 1150-1200°C for forging. Do not forge below 850°C.

2. Annealing

Heat the AISI 4140 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.

3. Stress Relieving

When parts are heavily machined, ground or otherwise subject to cold work, stress relieving will be beneficial prior to hardening.

4. Hardening

AISI 4140 steel is usually supplied ready heat treated to 18-22HRC. If further heat treatment is required annealed AISI 4140 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.

5. Tempering

Heat the AISI 4140 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 value.

6. Surface Treatment

Plate: Origin Black, Orign cold rolled bright, Machined, Grinded

Bar: Origin Black, Orign cold rolled(drawn) bright, Turned, Peeled, Grinded