Casting Steel Bal

OTHER

Classification

High chromium alloy casting ball, medium chromium alloy casting ball, low chromium alloy casting ball

Application

Casting steel ball is mainly used in cement plant, chemical plant, power plant, quartz sand factory, silica sand factory and other dry grinding field.

Advantages

Cost-effective and low cost, wide application range, especially in cement industry as the representative of the dry grinding field

Production Process Flow of Casting Steel Ball

Inspection of raw materials----Materials ratio---Heating and melting of Intermediate frequency furnace---Pouring into mold--- Quenching----Tempering----Testing---Package

Quality Detection and Standard of Casting Steel ball

The standard chemical components of casting steel ball.(We can also produce the steel ball according to the requirement of customers

Code	Chemical Composition（Mass Fraction），℅
	C	Si	Mn	Cr	Mo	Cu	V	Ti	P	S
ZQCrG1	2.0-3.5	≤1.0	0.5-2.5	10-16	≤1.0	≤1.0	≤0.3	≤0.15	≤0.1	≤0.1
ZQCrG2				16-22
ZQCrG3				22-28

2.Nominal diameter, allowable deviation, the maximum diameter and the minimum diameter

Nominal diameter	20	25	30	40	50	60	70	80	90	100
Allowable deviation of diameter	+2.0 -1.0			+2.0 -1.0				+3.5 -1.0
Difference of the maximum diameter and the minimum diameter	≤1.8		≤2.4	≤3.0	≤3.6		≤4.2		≤4.6

3.Mechanical Property of casting steel ball

Code	Surface Hardness	Impact Test	Impact Fatigue Life
ZQCrG1	≥58	≥3	≥10000
ZQCrG2	—	—	—
ZQCrG3	—	—	—

Notes:1. The ball with diameter 100mm is used in impact fatigue test; the test height is 3.5m; the impact times of the ball with other diameter are calculated by this formula, Nx=N*100/D, N is time. 2. The impact toughness and impact fatigue life index is not treated as delivery basis.

Surface Quality

1. It is not allowed that crack, obvious porosity, slag inclusion, shrinkage, cold insulation, wrinkled skin and other casting defects exist on the surface.

2.Allowed defects on ball surface

Nominal Diameter	Allowed Surface Defects mm
Nominal Diameter	Spare Part on Gate	Sand Dipping Area	Residual Side	Depth	Single Hole Area	Total Area
20—35	1.5	16	1.5	1.5	12	25
40—60	2.0	25	2.0	2.0	16	35
70—100	2.5	36	3.0	2.5	20	50

Internal quality

It is not allowed that crack, obvious porosity, slag inclusion, shrinkage, cold insulation, wrinkled skin and other casting defects exist on the section which goes through center of gate and sphere.

Test Method and Rules

1.Impact test: cutting 10mm×10mm×55mm part through gate in ball as sample

2.Rockwell hardness specimen preparation: The surface of the ball takes the test after grinding to platform, and the grinded thickness is 1.5 - 5mm.

3. Chemical composition test: when the volume smelting furnace more than 0.5 tons, we should check the chemical composition furnace by furnace; when the volume smelting furnace not more than 0.5 tons, we should check the chemical composition once per shift. Once there is one furnace unqualified, we need to sample double furnace for test. If there is still one not qualified, this branch of balls is unqualified.

4. Surface hardness test: sampling from different location of each batch of heating furnace, the number of the ball≥ 5.Once there is one unqualified, we need to sample double balls for test. If there is still a ball not qualified, this branch of balls is unqualified.

5. Internal quality detection: we sample 1 largest size casting iron grinding ball in 100 tons the same type cast iron grinding ball of each continuous production. Once there is one unqualified, we need to sample double balls for test. If there is still a ball not qualified, this branch of balls is unqualified.