What are Martensitic Blow Bars?
A martensitic blow bar is a type of wear-resistant component commonly used in impact crushers for crushing hard and abrasive materials. These blow bars are manufactured from steels that undergo specific heat treatment processes to develop a martensitic microstructure, which imparts them with exceptional properties for crushing applications. In terms of hardness and toughness, martensitic steel blow bars are somewhere in the middle between the tough manganese blow bars and the hard chrome blow bars. With abrasive feed material, martensitic blow bars exhibit clear advantages when compared to manganese blow bars, and using martensitic blow bars minimises the high risk of breakage associated with the use of chrome blow bars.Blow bars made of martensitic steel are used in secondary crushing and to some extent in tertiary crushing.
Applicable Conditions
Properties: Martensitic steel has both hardness and impact resistance characteristics, compared with chrome steel, not easy to fracture. In addition, in abrasive material applications, martensitic sheet hammers have longer service life than manganese sheet hammers.
Recommended for:
- Construction waste
- Blasted limestone
- In case of very large feed sizes (depending on the geometry of the crusher inlet)
Grade and Chemical Composition
| Grade | Chemical Composition (%) | ||||||||
| C | Si | Mn | Cr | Mo | Ni | Cu | S | P | |
| 30Mn2CrSi | 0.25～0.35 | 0.5～1.2 | 1.2～2.2 | 0.5～1.2 | / | / | / | ≤ 0．04 | ≤ 0．04 |
| 30CrMnSiMo | 0.25～0.35 | 0.5～1.8 | 0.6～1.6 | 0.5～1.8 | 0.2～0.8 | / | / | ≤ 0．04 | ≤ 0．04 |
| 30CrNiMo | 0.25～0.35 | 0.4～0.8 | 0.4～1.0 | 0.5～2.0 | 0.2～0.8 | 0.3～2.0 | / | ≤ 0．04 | ≤ 0．04 |
| 40CrNiMo | 0.35～0.45 | 0.4～0.8 | 0.4～1.0 | 0.5～2.0 | 0.2～0.8 | 0.3～2.0 | / | ≤ 0．04 | ≤ 0．04 |
| 42Cr2Si2MnMo | 0.38～0.48 | 1.5～1.8 | 0.8～1.2 | 1.8～2.2 | 0.2～0.6 | / | / | ≤ 0．04 | ≤ 0．04 |
| 45Cr2Mo | 0.40～0.48 | 0.8～1.2 | 0.4～1.0 | 1.7～2.0 | 0.8～1.2 | ≤ 1.5 | / | ≤ 0．04 | ≤ 0．04 |
| 30Cr5Mo | 0.25～0.35 | 0.4～1.0 | 0.5～1.2 | 4.0～6.0 | 0.2～0.8 | ≤ 1.5 | / | ≤ 0．04 | ≤ 0．04 |
| 40Cr5Mo | 0.35～0.45 | 0.4～1.0 | 0.5～1.2 | 4.0～6.0 | 0.2～0.6 | ≤ 1.5 | / | ≤ 0．04 | ≤ 0．04 |
| 50Cr5Mo | 0.45～0.55 | 0.4～1.0 | 0.5～1.2 | 4.0～6.0 | 0.2～0.6 | ≤ 1.5 | / | ≤ 0．04 | ≤ 0．04 |
| 60Cr5Mo | 0.55～0.65 | 0.4～1.0 | 0.5～1.2 | 4.0～6.0 | 0.2～0.6 | ≤ 1.5 | / | ≤ 0．04 | ≤ 0．04 |
Note: This is only a standard chemical composition. The actual chemical composition needs to be adjusted according to the customer’s working conditions.
Metallographic Organization and Mechanical Properties
- Surface hardness: 44-57 HRC
- Impact strenght: 100-300 J/cm²
No just Martensitic!
Some customers are not satisfied with the service life of martensitic hammer. Based on this, our engineers developed new materials-MC series (Martensitic ceramic blow bars).
With the same working conditions, the service life of the newly designed blow bars can be increased by 150% ~ 200%.
