Middle chrome alloyed cast grinding bar

Steel bars-mid chrome

Middle chrome alloyed cast grinding bar

Specifications

(mm)Specification
¢8 ¢10 ¢12 ¢14 ¢16 ¢18 ¢20 ¢20*25 ¢25*30 ¢30*35 ¢35*40

Chemical Composition

Chemical Composition
C Si Mn Cr Mo Cu Ni Nb Ti Zr V B P S
Multi-ball I 1.8-3.2 0.5-1.5 0.3-1.5 3.2-7.0 ≤0. 5 ≤0. 8 ≤0. 5 ≤0. 2 ≤0. 5 ≤0. 5 ≤0. 5 ≤0.1 ≤0.15 ≤0. 1
Multi-ball II 1.8-3.2 0.5-1.5 0.3-1.5 7.0-10 ≤0. 5 ≤0. 5 ≤0. 5 ≤0. 2 ≤0. 5 ≤0. 5 ≤0. 5 ≤0.1 ≤0.15 ≤0. 1

Properties and Microstructure

Designation (HRC) Microstructure
 Multi-bars I 48-56 P+C
 Multi-bars II 50-62 P+C

The bar with chromium content from 3.0% to 7.0% and the carbon content between 1.80% -3.20% is called middle chrome alloyed cast grinding bar. Its impact value ak≥2.0J / cm 2, and the hardness (HRC) must be above ≥47 in national standard. In order to ensure the balls quality, it need high-temperature tempering to eliminate the stress of casting. If the balls surface is dark red, it indicates that the product has been tempering treatments, and the original color in ball surface indicates that the product is not hot tempered.