Sheaves, Pulley in Cast Steel
Expertise products made in China
Product definition
The product covered here is a dragging device which is installed in the derrick, and support the mine hoist, hoist support drag between the rolls to enhance the container, and guide the use of wire rope steering. Rope groove is with plastic lining or plastic block, which will increase the service life of wire rope.
Material
This material is the casting steel G42CrMo4 ISO14737:2003(E), which is a fully killed steel, vacuum-degassed and processed to a fine grain size structure with improved properties both in toughness and in elongation.
- Chemical composition: (%)
|
Elements |
C |
Si |
Mn |
P |
S |
Cr |
Mo |
Ni |
V |
Cu |
|
Required |
0.38-0.45 |
≤0.6 |
0.6-1 |
0.025 |
0.02 |
0.8-1.2 |
0.15-0.25 |
≤0.4 |
≤0.05 |
≤0.3 |
- Mechanical properties
Checked at room temperature in the delivery condition i.e. after completion of the quality heat treatment from cylindrical cast-on test blocks (∅ 60 mm x 250 mm) available on every Sheaves: both the sample preparation and the testing comply with ASTM A 370-96.
|
Properties |
Yield strength |
Tensile strength |
Elongation |
Impact Value |
|
Required |
≥650 |
≥790 |
≥10 |
27 |
- Delivery condition: Hardening and tempering.
Manufacturing
All operations are carried-out at the in-house foundry plant.
- Molding
The castings are manufactured in a workman-like manner as required in the German standard DIN EN
1599-1: August 1997, ruling the delivery conditions of castings. The molding is individually carried out within a modular flask by using a sand preparation based on resin bonding.
- Melting
The melting is carried out in the oxygen steel plant ( 2 off 180 t BOF converters ); the ladle capacity allows a continuous bottom pouring process the speed of which is permanently controlled. The metal analysis is checked by using a computer linked spectrograph.
- Heat treatment
Every sheave undergoes a combined quality heat treatment (Hardening and tempering) aiming both to grain refining and to stress relieving.
- Rough machining
In order to meet the inside quality free of defect, we rough machine each sheave foe inner NDT control.
- NDT testing
UT: ASTM A609 Level Ⅱ for the groove and boss center.
MT: 100% ASTM A125 level Ⅰ
- Fine machining
Fine machine every sheave totally according to drawings.
- Fettling and dressing
The castings are coated by antirust oil FPC-600 for transportation.
Delivery
Every sheave is packed well and ready for delivery.
Quality assurance
The fabrication route is governed by the provisions of the implemented Quality System ISO 9001: 2000.
The standard documentation ensures the full traceability of every process step:
- Manufacturer test certificates according to DIN EN 10.204 § 3.1 including chemical composition, mechanical properties and non-destructive examination;
- Dimensional check supported with a “as-built“ sketch;
- Record of the quality heat treatment;
Service philosophy
We endeavor to propose options in terms of design engineering in taking advantage of our double experience as manufacturer, always targeting the optimization of their service life.
Skill with sheave
Further information on delivery program as well as useful advises on product, design, material and application are provided by the customer service team of the foundry department: it will support you actively in helping you to elaborate the right solution.
Whenever you need assistance, please contact:
Emily Liu Phone: +86 13918839495 Facsimile: +86 21 33847960 Sales2@special-metal.com
