35CrNiMo Steel Reel Of Cold Mill Machine

35CrNiMo Steel Reel Of Cold Mill Machine

35CrNiMo is a kind of high strength and high toughness alloy structural steel with good hardenability, fatigue resistance and wear resistance, which is widely used in the key parts of cold rolling mill.

Application scene of 35CrNiMo steel sleeve of cold rolling mill

In the cold rolling mill, 35CrNiMo steel sleeve is mainly used for the following key parts:

Roll bearing seat

Support rolls and withstand high radial and axial loads, requiring high compressive strength and fatigue resistance.

Drive connection sleeve

Deliver rolling torque with high torsional strength and wear resistance.

Guide and positioning sleeve

Ensure accurate roll alignment, reduce vibration and unbalance load, and improve rolling accuracy.

Advantage:

High-strength (tensile strength ≥ 980MPa) is applicable to high load cold rolling condition.

Good low temperature toughness (- 40 ℃ with high impact energy), suitable for high speed rolling.

Excellent hardenability (critical diameter approx. 80mm) for large, thick-walled sleeves.

Heat Treatment Process of 35CrNiMo Steel Sleeve for Cold Rolling Mill

Preliminary heat treatment (after forging/casting)

Normalizing (880~900 ℃ air cooling): refining grain, eliminating forging stress and improving machinability.

Annealing (680~700 ℃ furnace cooling): reduce hardness (HB ≤ 220) for subsequent machining.

Final heat treatment (tempering treatment)

Quench:

Heat to 850~870 ℃ (austenitization), and the holding time is calculated as 1.5min/mm.

Oil quenching (small size) or water-oil dual medium quenching (large size) to ensure full section quenching.

Tempering:

Temper for 3~4 hours at 560~600 ℃ to obtain tempered sorbite structure.

Target Performance:

Tensile strength ≥ 980MPa

Yield strength ≥ 835MPa

Impact energy ≥ 60J (normal temperature)

Hardness HRC 28~32

Surface strengthening (optional)

High frequency quenching: local hardening of butt contact surface to HRC 50~55, depth 2~3mm.

Nitriding treatment: 500~520 ℃ gas nitriding, surface hardness ≥ HV 800, improving abrasion resistance.

GW Precision cold rolling mill steel sleeve is widely used in aluminum/copper/stainless steel foil, plate,strip and other industries . 

Since the steel sleeve work under high speed rotation, concentricity , dynamic balance and other requirements are strict, which has a great impact on the product qualification rate and later reprocessing, we usually adopt centrifugal casting for the production process of steel sleeve . 

35CrNiMo steel sleeve can meet the high load and high precision requirements of cold rolling mill through centrifugal casting/forging+tempering heat treatment+precision machining, especially applicable to high speed rolling and heavy load working conditions. Key control points are heat treatment process optimisation and surface strengthening to extend service life.