Hot Rolling Mill Machine Of Operate Side Work Roller Rolling Mill Block Shaft

Hot Rolling Mill Machine Of Operate Side Work Roller Rolling Mill Block Shaft

Operating side work roll mill frame shaft of hot rolling mill

(Suitable for hot rolling production lines of plate and strip/section steel)

1、 Application scenarios

1. Core functions

Roller positioning and force transmission:

Maintain the stability of the working roll under the action of rolling force (maximum 30MN) and bending force (± 1000kN)

Endure the instantaneous impact load of biting steel (impact coefficient 2.0-3.5)

Thermal management:

Working in a rolling temperature environment of 400-800 ℃, the instantaneous surface temperature can reach 300-450 ℃

Need to resist periodic thermal stress (>10 ⁵ cycles/year)

2. Typical working conditions

Mechanical load: Hertz contact stress 1000-1500MPa, torsional vibration load (critical speed should avoid working speed 1.5-2.5 times)

Wear environment: Iron oxide scale abrasive particles (HV800-1100)+rolling lubricant high-temperature carbonization deposition

Material selection and optimization of the working roll mill frame shaft on the operating side of the hot rolling mill

1. Base material

Material grade, core advantages, applicable scenarios

50CrMoV high temperature strength (σ 0.2 ≥ 650MPa at 500 ℃) wide and thick plate rolling mill (roll body>3m)

Low cycle fatigue performance (Nf ≥ 5000 times at Δ ε t=1%) of 38CrNiMoV high-strength strip steel during rolling

H13 improved heat-resistant cracking (thermal conductivity 24W/m · K) stainless steel hot-rolled

2. Key reinforcement technologies

Bearing mating surface:

Laser quenching (hardening layer depth 2-3mm, HRC54-58)

Plasma spraying WC-10Co4Cr (porosity<0.8%)

Threaded connection area: boronizing treatment (Fe2B layer 50-80 μ m)

3. Innovative material applications

Gradient functional axis:

Core: 25Cr2MoV (high toughness)

Surface: Stellite 21 (resistant to high temperature wear)

Diffusion bonding through hot isostatic pressing (HIP)

3. Heat treatment system

Vacuum quenching: 1020 ℃ × 3h (nitrogen cooling)

Double tempering: 560 ℃× 4h+520 ℃× 6h (oil cooled)

Stabilization treatment: Deep cooling (-120 ℃× 8h)+aging (250 ℃× 24h)

4. Surface strengthening

Composite processing:

Shot peening (Almen strength 0.4-0.45mmN)

Ionic sulfurization (FeS layer 1-2 μ m)

Laser texturing (Sa=3-5 μ m)

*Key processes:

Constant temperature grinding of bearing position (coolant 20 ± 1 ℃)

Electrochemical machining of transition fillet (R angle accuracy ± 0.05mm)*

Typical parameters of the working roll mill frame shaft on the operating side of the hot rolling mill

Requirements for parameter indicators

Axis diameter tolerance of φ 320 ± 0.008mm

High temperature creep rate ≤ 1 × 10 ⁻⁷%/h (500 ℃/200MPa)

Vibration acceleration ≤ 4.5m/s ² (ISO 10816-8)

The service life of this shaft in a hot rolling mill is 2-3 years (with an annual rolling capacity of 1.5-2 million tons), and it can be extended to 5 years using gradient materials. The proportion of thermal fatigue failure is greater than 60%, and the current research and development focus is on nanostructured thermal barrier coatings.