The following outline gives the differences between ARCOPLATE and Creusabro.
ARCOPLATE is produced by introducing alloys with high amounts of chromium and carbon which promotes the formation of chromium carbide, an extremely hard particle (+1500 Vickers Hardness) these hard chromium carbides are supported by a softer, but much tougher matrix.
The formation of carbides is not the only criteria for the good abrasive resistance of ARCOPLATE. Carbide volume and orientation is very critical to obtain maximum abrasion resistance.
In the microstructure the chromium carbides are hexagonal, rod-like formations (white) held in the dark matrix with the wear resistance being optimized when the long cylinder-like chromium carbides are perpendicular to the surface. They are anchored within the tough matrix and do not become dislodged or easily fractured as wearing progresses.
ARCOPLATE’s chromium carbide volume and orientation are controlled by our unique cooling process.
To maximize abrasion resistance our typical chemical composition consists of approx. 38% Chromium, 5.2% Carbon plus small additions of Manganese & Silicon, the remainder is Iron. Due to large amounts of chromium and carbon the chromium carbides are large and numerous and gives ARCOPLATE excellent abrasion resistance.
Creusabro is a Quenched and Tempered steel plate manufactured in France.
It is oil quenched (as opposed to Bisalloy which is water quenched) which effects the cooling rates, and thereby determines the degree of hardening. To overcome the inadequacies associated with water quenched Q & T plate, Creusabro have added alloying elements to the steel that enhanced uniform hardness. Additions of chromium & titanium are made to induce the formation of abrasion resistant carbonitrides and to yield steels of superior wear resistance.
Dependent upon the grade, Creusabro uses “small” amounts of chromium, molybdenum and titanium to form micro-carbides.
Unlike ARCOPLATE which consists of a microstructure of large and dense carbides (a proven way of reducing abrasion), Creusabro’s microstructure of micro-carbides utilizes (on a smaller scale) the same principles for combating wear.
Low Stress or Scratching Abrasion is the most predominate in the mining industry with steel being abrading away by the abrasive material removing slivers from the wearing steel.
The basic principles of scratching abrasion are shown by these diagrams.
The length of the metal sliver removed varies based upon the chemical composition, microstructure
and bulk hardness of the material being abraded.
The first diagram shows the long sliver generated on conventional Q&T plate, diagram 2 shows a smaller sliver being generated due to the presents of the micro-carbides in Creusabro and the last diagram shows the abrasive particle being deflected by ARCOPLATE’s chromium carbides (+1500Hv) and only producing a very minimal sliver.
A quantitative method measuring a material’s resistance to scratching abrasion is the Dry Sand Rubber Wheel Test (ASTM G65) which characterizes materials in terms of weight loss under a controlled set of laboratory conditions. Field tests may be influenced by other parameters like impact, corrosion or heat nevertheless the ASTM G65 test gives a valuable insight into a materials field performance.
The following ASTM G65 test report –shows the results of ARCOPLATE against 450HB plate displaying an average wear factor of > 8:1over the Q&T liners
From Table 1: Volume Loss Scenario mm3
Extreme Low Arcoplate v Extreme High Comp
CONVENTIONAL WELD OVERLAY
If a comparison is made between Creusabro and conventional Q & T plate it stands to reason the Creusabro’s microstructure and work hardening effect would give better wear resistance – it would also probably cost more – however ARCOPLATE and Creusabro are from 2 different steel groups and as shown they have different wear resistant characteristics.
Without quantitative testing and based only upon Creusabro 4800 literature of offering 50% extra service life over conventional water quenched plate, we would predict that ARCOPLATE 1600 could obtain 4 to 5 times better service life over Creusabro.
We are also confident that ARCOPLATE will outperform Creusabro 8000 attaining extra service life to provide the lowest total cost of ownership.
ARCOPLATE’s Extra Advantage
Apart from ARCOPLATE’s excellent abrasion resistance characteristics, its bulk hardness and high percentage of chromium carbides allows it “polish” to a finish that reduces / eliminates hang up or carry back on mobile equipment, chutes & hoppers.
Unlike the well documented effects of abrasion, material hang up / carry back is the “acceptable” (it should not be) cost that effects efficient material flow and reduces machine availability times.