Super High Chromium Grinding Ball

production technology

 

 A super-high chromium grinding ball characterized by its chemical composition in percentage by weight as follows:

C 2.00 ~ 2.70, Si 0.30 ~ 0.80, Mn 0.40 ~ 1.00, P≤0.10, S≤0.06, Cr 18.00 ~ 21.00, Re 0.06 ~ 0.12, the margin is Fe.

 

The processing technology of the ultra-high chromium grinding ball is as follows:

(1) smelting the metal material after precise mixing is melted into hot metal by acid medium frequency electric furnace, sampling, chemical composition analysis, and reserve use in line with the standard;

(2) The primary metamorphic hot metal is heated to a temperature of 1500 ~ 1540℃, and the inocent rare earth silicon with a weight of 0.2% of the weight of the hot metal is added to the furnace 5 minutes before the oven for the first metamorphic treatment to obtain the primary metamorphic hot metal;

(3) Deoxidation treatment to add the weight of 0.15% of the weight of aluminum to the hot metal after a metamorphic treatment, deoxidation treatment, to obtain the deoxidized hot metal;

(4) After secondary metamorphic treatment, yttrium rare earth with the weight of 0.2% of the weight of the deoxidized hot metal is added to the second metamorphic treatment to obtain the secondary metamorphic hot metal;

(5) When the hot metal temperature after secondary metamorphic treatment drops to the casting temperature of 1380 ~ 1400℃, the casting is cast into the prefabricated metal iron mold, and the casting ball is removed after the mold is solidified; Clean the gate and get the rough ball.

(6) Quenching the blank ball is heated in the quenching furnace to 970 ~ 990 ° C, held for 2 ~ 2.5 h, and then poured into the constant temperature oil tank, cooled to the casting ball temperature below 200 ° C to produce oil, after quenching casting ball;

(7) Tempering will be quenched after the cast ball tempering, tempering temperature is 420 ~ 430℃, holding time is 6 ~ 6.5h, after the oven slow cooling to 200℃ pit, air cooling to room temperature, to obtain the finished grinding ball, that is, ultra-high chromium grinding ball

 

Performance ratio of ultra-high chromium mill ball to high chromium mill ball

 

1.In terms of the overall wear and consumption of the initial ball, the ultra-high chromium ball is smaller than the ordinary high chromium ball.

In terms of the wear degree of steel balls of different quality, the cement consumption of super high chromium ball tons is concentrated in the second warehouse, mainly φ25mm steel balls; The consumption of ordinary high-chromium ball tons of cement is concentrated in a warehouse, mainly φ50mm steel balls.

2.There is no difference between the two in the comparison of mill production and operation.

The superiority of the ultra-high chromium ball and the ordinary high chromium ball is not directly related to the attribute quality of the steel ball itself, but mainly depends on the good operation of the mill.

3.In terms of the cost of loading the initial ball, the cost of the ultra-high chromium ball is larger than that of the ordinary high chromium ball

Through the performance ratio of the two, whether the first ball of the mill uses ultra-high chromium balls or ordinary high chromium balls, we must strictly implement the interim measures for the consumption management of cement grinding steel balls, effectively reduce the consumption of steel balls, reduce production costs, and improve the production quality of the mill. At the same time, it is also necessary to combine the quality structure of cement, the particle size and hardness properties of the material particles, and find out a set of economic management plan.

 

BASIC INFO

 

Grinding media information
Model NO.	Steel balls	Material	Chrome
Content	≥10%	Processing Type	Casting
Hardness	58-68HRC	Customized	Customized
Broken Rate	＜0.5%	Heat Treatment	Oil Quenching
Size	10mm-140mm	Color	Black
Transport Package	Durm or Bag	Moder No.	Zqcr10
Trademark	Chengda	Specification	High Chrome Grinding Media
HS Code	7325910000	Origin	China
Production Capacity	60000 Tons
Usage	Construction,Machinery,  chemical Petroleum, Grind,Refractory Material,  Cement Plant ,  Mining Mill

 

CHEMICAL COMPOSITIONS(%)

 

Designation	Chemical Composition(%)
	C	Si	Mn	Cr	Mo	Cu	Ni	P	S
ZQCr26	2.0-2.6	≤1.0	0.3-1.5	23.0-27.0	≤1.0	≤1.0	≤1.0	≤0.06	≤0.06
ZQCr20	2.0-2.6	≤1.0	0.3-1.5	18.0-23.0	≤1.0	≤1.0	≤1.0	≤0.06	≤0.06
ZQCr15	2.0-2.6	≤1.0	0.3-1.5	14.0-18.0	≤1.0	≤1.0	≤1.0	≤0.06	≤0.06
ZQCr12	2.2-3.0	≤1.0	0.3-1.5	10.0-14.0	≤1.0	≤1.0	≤1.0	≤0.06	≤0.06
ZQCr8	2.2-3.0	≤1.0	0.3-1.5	7.0-10.0	≤1.0	≤0.8	≤1.0	≤0.06	≤0.06
ZQCr5	2.2-3.2	≤1.0	0.3-1.5	4.0-6.0	≤1.0	≤0.8	≤1.0	≤0.08	≤0.08
ZQCr2	2.2-3.2	≤1.0	0.3-1.5	1.0-3.0	≤1.0	≤0.8	≤1.0	≤0.10	≤0.10
ZQCADI	3.3-3.9	2.4-3.0	1.4-1.9	0.2-0.5	≤0.5	0.1-0.5	0.1-0.5	≤0.05	≤0.05

 

SPECIFICATION

 

Specification (mm）	Weight of Each Ball (Kg)	Pcs/ton	T/m
φ15	0.017	58824	4.94
φ17	0.024	41667	4.91
φ20	0.037	27027	4.89
φ25	0.070	14286	4.87
φ30	0.110	9091	4.85
φ40	0.257	3891	4.76
φ50	0.500	2000	4.70
φ60	0.867	1153	4.66
φ70	1.070	729	4.62
φ80	2.050	487	4.60
φ90	2.900	345	4.58
φ100	4.000	250	4.56
φ110	5.300	188	4.55
φ120	6.800	147	4.54
φ125	7.750	129	4.52
φ130	8.740	114	4.50

 

Mechanical Properties And Microstructure

 

Designation	HRC	AK(J/CM²)	Microstucture	Falling Times
ZQCr28	≥58	≥4.8	M+C	≥18000
ZQCr26	≥58	≥4.8	M+C	≥18000
ZQCr20	≥59	≥4.8	M+C	≥18000
ZQCr15	≥60	≥4.8	M+C	≥18000
ZQCr12	≥60	≥4.5	M+C	≥18000
ZQCr8	50-65	≥3.5	P+C/M+C	≥12000
ZQCr5	49-62	≥3.0	P+C/M+C	≥12000
ZQCr2	≥48	≥3.0	P+C	≥10000
ZQCADI	55-60	≥10	B+Fe	≥25000
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