cold rolling mill roll
material:9Cr2Mo,9Cr2MoV,9Cr3Mo
HRC:57-61
barrel roll:upto 4000mm,Dia :upto 1000mm
ISO:9001-2000
cold rolling mill roll
jinyu cutting tools Co.,Ltd division is accredited with ISO-9001:2000 certificate.
jinyu rolls out world class forged rolls- Sendzimir mill rolls / cluster mill rolls, 6Hi, 4Hi and 2Hi mill rolls, skin-pass rolls etc.
The rolls are prone to very tough working conditions and have to be perfect in terms of wear resistance, toughness and hardness. Right from the raw-material inspection, to heat treatment ,to grinding and final dispatch, all rolls undergo very stringent quality checks.
The raw-material is generally imported from renowned sources from worldwide and is checked for – macro structure analysis, micro structure analysis, ultrasonic soundness and heat-treatment response. Proper heat-treatment cycles ensure hardness uniformity and proper depth of hardness.
The rolls are finally inspected for –
Surface hair-line cracks by magnetic particle testing,
Sub-surface defects like inclusions by ultrasonic testing with the help of angular probes
Internal defects by ultrasonic testing with the help of straight probes
Hardness by Rockwell and equotip hardness testers.
technical data
| GB | Chemical composition(mass fraction)/% | |||||||||
| C | Si | Mn | Cr | Mo | V | Ni | Cu | S | P | |
| 9Cr2 | 0.80~0.95 | ≤0.40 | ≤0.40 | 1.30~1.70 | __ | __ | __ | __ | ≤0.030 | |
| 8Cr2MoV | 0.80~0.90 | 0.15~0. 40 | 0.30~0.50 | 1.80~2.40 | 0.20~0.40 | 0.05~0.15 | ≤0.25 | ≤0.25 | ||
| 9Cr2Mo | 0.85~0.95 | 0.25~0.45 | 0.20~0.35 | 1.70~2.10 | 0.20~0.40 | __ | ||||
| 9Cr2MoV | 0.20~0.30 | 0.10~0.20 | ||||||||
| 9Cr3Mo | 2.50~3.50 | 0.20~0.40 | __ | |||||||
| 8Cr3MoV | 0.78~1.10 | 0.40~1.10 | 0.20~0.50 | 2.80~3.20 | 0.20~0.60 | 0.05~0.15 | ≤0.80 | ≤0.25 | ≤0.025 | |
| 8Cr5MoV | 0.78~0.90 | 0.40~1.10 | 0.20~0.50 | 4.80~5.50 | 0.20~0.60 | 0.10~0.20 | ≤0.020 | |||
surface hardness of barrel roll
| serial number | surface hardness of barrel roll(HSD) | Recommended for |
| 1 | ≥95 | work roll of pinch pass mill and finishing mill |
| 2 | 90~98 | cold work roll of metal plate and strip |
| 3 | 75~90 | cold work roll of metal plate and strip |
hardening layer hardness of cold barrel roll
| barrel roll diameter/mm | surface hardness of barrel roll(HSD) | hardening layer hardness/mm | ||
| 2%Cr | 3%Cr | 5%Cr | ||
| ≤300 | ≥95 | 6 | 15 | 15 |
| ≤300 | 90~96 | 8 | 20 | 20 |
| ≤300 | 75~90 | 10 | __ | __ |
| 301~500 | ≥95 | 7 | 20 | 25 |
| 301~500 | 90~96 | 12 | 25 | 30 |
| 301~500 | 75~90 | 14 | __ | __ |
| >500 | ≥95 | 8 | 20 | 25 |
| >500 | 90~96 | 13 | 25 | 35 |
| >500 | 75~90 | 15 | __ | __ |
