Tenfaye is the professional large gear rings manufacturer in China. When dealing with situations where some customers provide unclear material specifications, some customers provide niche materials that are not European or American standards, or some customers only provide hardness values combined with other technical parameters, our engineer will recommend Chinese national standard materials for girth gears to customer reference and selection before quotation.
 
The following is an analysis of the chemical composition and mechanical properties of common Chinese national standard materials for large gear rings.

1. Chemical Composition
1.1 The chemical composition of each cast steel grade shall comply with the requirements specified in Table 1.
1.2 Unless otherwise specified, residual element content shall not be used as acceptance criteria.
1.3 When required by the purchaser, finished product chemical composition analysis may be performed, and the allowable deviation of finished product chemical composition shall comply with the requirements of GB/T 222.
Table 1
Chemical Composition (Mass Fraction)                                                         %

Material Grade	C	Si	Mn	S	P	Cr	Ni	Mo
ZG35CrMo	0 . 33~0 . 37	0 . 30~0 . 50	0 . 50~0 . 80	≤0 . 025	≤0 . 025	0 . 80~1 . 20	—	0 . 20~0 . 30
ZG42CrMo	0 . 38~0 . 45	0 . 30~0 . 60	0 . 60~1 . 00	≤0 . 025	≤0 . 025	0 . 80~1 . 20	—	0 . 20~0 . 30
ZG45CrMo	0 . 43~0 . 47	0 . 30~0 . 60	0 . 70~1 . 00	≤0 . 025	≤0 . 025	0 . 90~1 . 20	—	0 . 25~0 . 35
ZG35CrNiMo	0 . 32~0 . 37	0 . 30~0 . 50	0 . 70~1 . 00	≤0 . 025	≤0 . 025	0 . 60~0 . 90	0 . 60~0 . 90	0 . 40~0 . 50
ZG40CrNiMo	0 . 37~0 . 43	0 . 30~0 . 50	0 . 70~1 . 00	≤0 . 025	≤0 . 025	0 . 60~0 . 90	0 . 60~0 . 90	0 . 40~0 . 50
ZG34Cr2Ni2Mo	0 . 32~0 . 37	0 . 30~0 . 60	0 . 60~1 . 00	≤0 . 025	≤0 . 025	1 . 40~1 . 70	1 . 40~1 . 70	0 . 15~0 . 35
ZG40CrNi2Mo	0 . 37~0 . 43	0 . 30~0 . 50	0 . 70~1 . 00	≤0 . 025	≤0 . 025	1 . 00~1 . 40	1 . 40~1 . 70	0 . 30~0 . 40
Notes: ·  Residual element content: Ni≤0.30%, Cu≤0.25%, V≤0.05%, total residual element content ≤1%. If not required by the purchaser, residual elements shall not be used as acceptance criteria. ·  Trace amounts of V, Ti, Nb, B, and Re elements may be added.

2. Mechanical Properties
The mechanical properties of each cast steel grade shall comply with the requirements specified in Table 2.
Table 2 Mechanical Properties Large gear rings are one of the most critical components in the transmission systems for rotary kilns and ball mills. The chemical and mechanical properties of girth gear will directly affect the stability of the rotary kiln and ball mills transmission system, operational stability, service life, and equipment availability.
If you have requirements for girth gears for mill and kilns or questions about large gear rings, please contact us at any time. As a professional large gear ring casting manufacturer, we are worthy of your trust.