Why Hardox 600 can compete with high-chromium white alloy castings, Ni-hards and hardfacing
October 05, 2015 12:00 CET 6 min read
Hardox® 600, the ultimate hard and tough wear plate, is made for extreme wear conditions. Despite its high hardness it can still be cut and welded.
What is Hardox 600?
Hardox 600 is a Q&T martensitic wear plate for applications that demand high resistance to abrasion and wear. Delivering a hardness of 600 Brinell, it offers a unique combination of weldability, hardness and toughness. It brings a level of user-friendliness not found in many other steels designed for high wear resistance and eliminates the need to sacrifice wear resistance to enhance impact strength.
Please read the product data sheet for detailed dimensions and specifications.
What can Hardox 600 replace?
If your components are exposed to sliding wear from very hard abrasives of 900–1000 Vickers (HV), they can substantially increase their wear life by using a 600 Brinell wear plate.
Not only can you use Hardox 600 to replace wear plates having a lower hardness, but you can use it instead of hardfacing and overlay plate, white iron chromium castings or ceramics. Thanks to its properties, Hardox 600 can withstand the impacts that often lead to fracture and destruction of these materials.
White iron chromium castings
The three main types of grades are Ni-Cr (Ni-Hards), Cr-Mo and high Cr. These materials mainly consist of precipitated chromium carbides in an austenitic or martensitic matrix.
- The low fracture and impact toughness of the white iron chromium castings increases the crack susceptibility of the wear part.
- Because of the composition and carbide fraction, common workshop methods like welding, cutting and machining are difficult.
- Castings only permit limited flexibility in component design because of fixed mold sizes, as well as narrow tolerances for reaching optimal fitting.
Hardfacing and overlay plate
Overlay plate and hard facing come in a wide range of compositions and hardness levels. As with the white iron castings, their wear resistance is gained by precipitates of chromium carbides in a martensitic or austenitic matrix.
- Plate distortion and severe cracking is common in some manufactured overlay plate because of the intense heating and cooling during the welding process. This will be detrimental to high-impact environments that will cause the overlay to spall and break apart.
- Because of dilution problems associated with welding and thermal spraying of hardfacing deposits, parts of the hardfacing beads often fall off when exposed to heavy abrasion.
- The lack of a smooth surface finish in some wear overlay plates may increase friction and thus cause material hang-up on machinery.
Ceramic materials, such as aluminum and silicon oxides, exhibit exceptional abrasion resistance due to very high hardness (1800–2000 HV).
- Low toughness limits its use to applications that are exposed only to modest levels of impact.
- Since ceramics are not weldable, alternative and sometimes more expensive attachment solutions must be considered.
- Combined with high material costs, ceramics have seen only limited use in heavy abrasive environments.
How does Hardox 600 perform?
Resistance to abrasive wear is not an intrinsic material property; it depends on the application. Materials that exhibit superior abrasion resistance under one set of conditions might perform poorly under different conditions. Selecting material is complex, requiring wear know-how and the consideration of practical issues like application design, maintenance routines, workshop requirements, and material and fabrication costs.
The graph shows the relative wear life of Hardox 600 compared to different grades of white iron chromium castings, chromium carbide-rich hardfacing deposits/overlay and ceramics, when exposed to sliding wear from abrasives of 900–1000 HV.
In general, Hardox 600 shows a somewhat inferior wear resistance compared to these types of wear-resistant materials. But under certain conditions Hardox 600 shows a wear resistance equal to or better than chromium carbide-rich castings and hardfacing deposits.
When considering function, wear resistance is not the only factor in terms of hardness or fraction of hard chromium carbides that determines wearpart performance. Material crack susceptibility also plays a part. In this case, Hardox 600 offers an impact toughness that exceeds the toughness of white iron castings, ceramics, and overlay and hardfacing deposits.
What are the benefits?
Here are some other benefits of Hardox 600.
- Steel plates are widely available.
- All properties are inherent in the as-delivered plate.
- No extra heat treatment is needed.
- Large areas can be protected at a relatively low cost.
- Provides uniform and consistent properties within the plate.
- Machining, welding and cutting can easily be done using a standard workshop setup.
- Spare parts can be quickly and easily manufactured for direct installation and replacement.
- Close tolerances of fabricated components are easy to reach.
- Provides a unique combination of hardness, yield strength and impact toughness to permit low-weight wearparts design.
- Superior impact toughness
Add up the benefits
+ High wear resistance
+ Easy access to steel plate
+ Uniform properties
-------------------------------------------------= Lower cost per service hour
What applications can I use Hardox 600 in?
Hardox 600 has been successfully used as linings in applications such as conveyor systems, wear strips, feeders, chutes and concrete mixers and in other high-wear equipment. In the recycling industry, it has been used in rotating hammers and in shredder knivesTo obtain the best performance, attach your Hardox 600 wear part to a rigid support for limiting the flexing. Additional stresses from structural loads should also be kept at a low level.
For more information, contact Technical Support.