Item

Unit

Standard Value

Actual measured value

Result

Inspection standard

SiO₂

-

50±2

48.40

Eligible

QB/T 2578-2002

Al₂O₃

-

35±2

34.65

Eligible

Fe₂O₃

-

-

0.44

-

CaO

-

-

1.49

-

Mgo

-

13±2

12.78

Eligible

Outlook quality

-

-

Meet the requirement

Eligible

XB/T 505-2003

Crack in the surface

-

No visible cracks available in the extremity and the flank

-

-

Defect in the hole wall

-

Could not exceed 0.1% extremity

-

-

Damage of edge

-

For each 28mmX18mm extremity, there should be less than 3 places of damage

-

-

Chiseled hole in the surface

-

The depth ≤ 1.6mm, the whole area of the chiseled hole ≤ 300mm², and the girth of the hole ≤ 6.4mm².

-

-

Rate of blocking hole

-

≤1.0%

-

-

Dimension tolerance

mm

Length ≤100 permitted tolerance±1.0

Meet the requirement

Eligible

Thermal expansion coefficient

≥15.0X10^-7

14.6X10^-7

Eligible

Intenerate temperature

≥1360

1364

Eligible

Heat and libration resistance

650

650-8 Never crack in one time

Eligible

Cubage density

g/cm³

0.45-0.55

0.50

Eligible

Water absorption

%

16.5,tolerance±2.0

16.85

Eligible

Compressive strength

kg/cm²

-

-

-

Axes A

-

≥106

143.8

Eligible

Axes B

-

≥14.5

20.5

Eligible

Axes C

-

≥1.7

3.2

Eligible

Cool libraest

-

-

Under the frequency of 100±50H 2 , after being librated for 3 hours, there aren't any damage and cracks

-

Test result