Custom machining large diameter steel outer ring gear
Application
Gea ring can be widely used in cement plant, mining, lifting, light
industry, chemical industry, transportation, construction and other
machinery and equipment deceleration mechanism.Advantage of Gear
- Products with Customers' Designs
- Strong Machining & Heat Treatment Abilities
- Strict Quality Control
- Prompt Delivery
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| | Cast Alloy Steel, Cast Carbon Steel, Forged Alloy Steel, Forged
Carbon Steel |
| | Integrated, Half to Half, Four Pieces and More Pieces |
| | Quenching & Tempering, Normalizing & Tempering, Carburizing &
Quenching & Tempering |
| | Annular Gear, Outer Gear Ring |
| | ISO, EN, DIN, AISI, ASTM, JIS, IS, GB |
We provide girth gears in three different designs
1. Fabricated steel
- forged ring
- rolled plate
Cast steel
Ductile (Nodular) cast iron
Fabricated gears became more common in the past and are constructed
with forged steel gear rim materials and electro welded body
structure. The rings are manufactured from a whole block of high
resistance alloy steel. After the rough machining of the ring, we
carry out hardening and tempering heat treatment in order to
improve the mechanical characteristic and therefore its relevant
performance.
Features
1. External teeth
Maximum diameter: 16000 mm
Toothed face width: 1700 mm
Maximum module: 45 by hob
Maximum module: 65 gear finishing cutter
2. Internal teeth
Maximum Diameter: 6500 mm
Maximum module: 25.4
Toothed face width: 400 mm
Forging material process
Forging
Final rolling
Furnace cooling
Control on production
Water quenching
Hardness testing
Rough machining
Ultrasonic testing and dimensional inspection
Final inspection certification
Standards/Certificates
UNI EN ISO
AWS
ASTM
ASME
DIN
We are leading supplier the Kiln Girth Gears for the various plants
as listed below.
1. Sponge Iron Plants 50TPD 100TPD 300TPD350TPD,500TPD,1000TPD
2. Cement plants as per customer requirement
3. Gears for phosphate mines, Alumina plant, kaolin-bentonite
Gear Cutting Capacity:
1. 100mm diameter to 16000mm diameter
2. 10Module to 70Module
The Kiln girth gears are available mainly in bi-part, four parts, 8
parts or multi segments as per the requirement and suitability with
the application of gear. In the field of grinding mill components,
We supply mill heads,feed inlet,grinding roller,cement kiln riding
ring, casting gears, shaft block .Also we supply mill shell of
welding structures and fabrications.
Quality assurance documents
The following reports are to be submitted to Quality Assurance:
a. Chemistry report
b. Physical report
c. Heat treatment documents
Specification for Steel Castings for Grinding Mills
d. Ultrasonic inspection report (before and after repairs)
e. Magnetic particle inspection report (before and after repairs)
f. Dimensional report
g. Weld repair maps
h. Weld procedures and Procedure qualification record
i. Welder qualification
j. Nondestructive testing inspector qualification
Item | Structural features | Processing measure | Test content |
Girth Gear | (1)GS42CrMo4Alloy Steel (corporate proprietary standards) HB 220~240 (2)semi-structured, Y-Spoke
(3)Helical
(4) reasonable sealing and alignment structure of alloy steel
(corporate proprietary standards) | (1) outer steel refining (R-H argon and vacuum treatment)
(2) proprietary cold mold hanging sand technology to ensure the
casting, the teeth dense
(3) normalizing (proprietary technology) to ensure that the tooth
surface hardness
After (4)rough hobbing, release time, repair the joint surface, then fine
roll
(5) proprietary homemade hob fine hobbing | (1)castings mechanical properties and chemical composition
(internal standard)
(2) roughing after sonic testing
(3)semi-finishing, finishing after ultrasonic testing and magnetic
particle inspection
(4) tooth surface magnetic particle inspection, hardness test
(5)tooth tolerance check
(6) the factory assembly load test to check the accuracy of the
size of gear |
| No. | process | processing measure | processing equipment | program of tests | inspection equipment |
1 |
prepare | 1. Material: high quality cast steel 2. Formulate reasonable casting process and ensure casting quality
by means of computer simulation of solidification 3. Formulate reasonable smelting process to ensure the chemical
composition of casting 4. Formulate reasonable heat treatment process to ensure Verify the mechanical properties of the casting
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2 |
modelling | 1. Strictly control the quality of type (core) sand, ensure the
strength and control of water 2. Sand tamping, inclined surface polishing, paint brush twice 3. Place the pouring riser and cold iron according to the process
requirements 4. Clean and bake as required cavity
|
sand mixer |
Check the quality of type (core) sand and surface sand 2. Check the cavity size Check the baking time
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3 |
Smelting casting | 1. Choose low S.P pig iron, select scrap steel, auxiliary materials
and alloy of baking furnace according to process 2. According to special process smelting, make steel S.P hazardous elements meet internal control standards 3. The finished molten steel is treated with argon blowing in the
ladle and R-H vacuum circulation degassing to make the molten steel
composition uniform, harmful oxygen (H, O) reduction, uniform
temperature, increase the fluidity of molten steel, so as to ensure
good liquid replenishing of the casting and prevent the casting
from porosity and other defects Strictly control casting temperature and casting speed according to
the provisions |
50 t furnace R-h vacuum circulation degassing equipment for ladle argon blowing
device
| 1. Furnace materials must meet the technological requirements 2. Control feeding temperature, feeding quantity, pure boiling
time, steel temperature 3. The direct reading spectrometer is used to quickly detect the
chemical composition in front of the furnace to ensure that the
equipment is in the best state during melting and the chemical
composition of the finished product meets the requirements during
pouring 4. Check the parameters of argon blowing and R-H vacuum treatment 5. Check the starting temperature and Pouring time
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Direct reading spectrometer The physical and chemical equipment
|
4 |
Cleaning and heat treatment | 1. The internal heat preservation time of casting mold shall not be
less than the process requirements 2. Sand falling, shot blasting, cutting and pouring risers meet the
technological requirements 3. Strictly carry out the blank heat treatment To ensure the uniformity of furnace temperature and refine the
original structure of casting
|
50t Inert falling sand machine and 8.5 ×12m Heat treatment furnace
| 1. Check the furnace temperature record 2. The sample is heat-treated with the casting in the same furnace,
and the mechanical properties are sent to be checked immediately 3. Check the surface quality of the blank Quantity, geometric dimension and machining allowance
|
The physical and chemical equipment |
5 | rough machining | 1. Reserve allowance for rough machining according to technological
provisions Artificial aging treatment
| Vertical lathe 8.5 ×12m Heat treatment furnace
| Check the size Visual inspection for defects ultrasonic inspection
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Ultrasonic Testing |
The technical requirements of a large CITICIC Gear ring:
1) is pretreated before normalizing surface hardening treatment,
the hardness should HB210 ~ 250; mechanical performance are the
ultimate strength Rb 690MPa, yield stress Rs 490MPa, elongation D5
11%, reduction of area W 25% , impact toughness Ak 30J; teeth
induction hardened, hardness HRC50 ~ 55; effective hardened layer
depth 3 ~ 5mm.
2) overall ultrasonic flaw detection, internal quality should meet
two requirements GB7233-87 standard requirements; tooth and fillet
magnetic particle inspection, quality should meet two requirements
GB/T9444-88 standards.
3) Note the casting is not rounded R5 ~ R10.
4) Tooth chamfer at both ends and 1 45b.5) by two and a half ring
gear tooth width of each ring coupling along the edge of a whole
ring made with high strength bolts, combined with the tooth surface
must be at the bottom center.
2 large ring gear manufacturing process
2.1 of rough
Steel casting blank is provided by CITIC Heavy Machinery Co., Ltd.
Heavy Forging plant, run by GB11352-89 standard specifies
requirements for modeling according to the casting process,
smelting, casting, hit boxes, cleaning, dressing castings;. During
inspection and acceptance by the drawings and Technical
requirements for steel blank
Checks, according JB/T6402-92 standards issued after acceptance
Down procedure.
2.2 roughing
Crossed by drawing and stay out allowance, alignment, connection,
processing both inside and outside the circle, combining face
milling, drilling and other processes.
2.3 Exploration injury
Overall ultrasonic flaw detection, internal quality should meet the
two requirements of GB7233-87 standards.
2.4 normalizing pretreatment
Semi-ring pairs normalizing and tempering treatment, provide a good
organization for subsequent surface hardening; press drawings
deformation of the half ring gear inspection after heat treatment.
2.5 Machining
First two and a half ring is made with high strength bolts
connecting the ring as a whole, the overall process by drawing a
circle Quannei Wai teeth and upper and lower end, and then drawing
and machining milling process requirements.
2.6 Elimination of processing stress
The overall ring annealed to eliminate stress.
2.7 overall ring surface hardening
IF along the alveolar tooth surface induction hardening, hardness
HRC50 ~ 55, effective hardened layer depth 3 ~ 5mm.
2.8 Final inspection
First, the detection frequency quenching, the hardness after
tempering ring gear cogging meets the requirements of the drawings;
secondly, to detect whether the maximum outer diameter larger size
D6944 as the deformation 3mm, the mechanical correction required
until qualified; Thirdly, tooth and fillet magnetic particle
inspection, quality should meet two requirements GB/T9444-88
standard requirements; Finally, according to the drawings and
technical requirements for final inspection.
Our Services
CITIC Heavy Industries is your business partner in the After
Market.
CITICIC is able to provide:
1. ENGINEERED SPARES - DESIGN AND MANUFACTURING
2. LARGE VOLUME STEEL AND IRON CASTING FOUNDARIES
3. HUGE MACHINE SHOP CAPABILITIES
4. TRAINING PROGRAMMES
5. PREVENTATIVE MAINTENANCE PROGRAMS
6. PREVETATIVE MAINTENANCE SERVICES
7. COMPREHENSIVE MAINTENANCE PROGRAMS
CITIC’s Field Service Engineers are trained specifically in the
CITIC brand group products but are capable of undertaking the
servicing of other OEM brands.
Our technicians are equipped with the most advanced technological
diagnostic equipment available to trouble shoot your equipment to
optimise performance and minimise down time.
CITICIC also has an extensive capability in supplying all you
consumable and electrical/ mechanical spare part needs.
FAQ
Quality Control
Physical & Chemical Identification Center
CITICIC owns a professional testing and metrology institute which
provides advanced testing methods such as nondestructive
testing, industrial chemical analysis, metallographic testing and
analysis, mechanical testing, sample preparation, meter/length
measurement, weighing apparatus verification, and weighman
inspection. Our metrology institute has taken a leading role in
China.
CITICIC owns nearly two hundred types of advanced testing
equipment, nine different measurement standards and nearly twenty
types of worldclass testing equipment which have been imported from
international locations such as Germany, Japan, USA,
UK and Belgium.
