GB/T 33878-2017 PDF in English
GB/T 33878-2017 (GB/T33878-2017, GBT 33878-2017, GBT33878-2017)
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| GB/T 33878-2017 | English | 80 |
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Steel cross wedge rolling -- Technological design principle
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Standards related to (historical): GB/T 33878-2017
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GB/T 33878-2017: PDF in English (GBT 33878-2017) GB/T 33878-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.85
J 32
Steel Cross Wedge Rollings - Technological Design Principle
ISSUED ON. JULY 12, 2017
IMPLEMENTED ON. FEBRUARY 1, 2018
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration Committee of the People’s
Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Terms and Definitions ... 4
4 Technological Design Principle ... 4
Foreword
This Standard is drafted in accordance with stipulations in GB/T 1.1-2009.
This Part is summarized by National Technical Committee 74 on Forging of
Standardization Administration of China (SAC/TC 74).
This Standard is mainly drafted by the following organizations. Hebei Dong An Jing
Gong Co., Ltd., University of Science and Technology Beijing, Beijing Ke Da Ji Xiang
Science and Technology Co., Ltd., Beijing Research Institute of Mechanical & Electrical
Technology, Hubei Tri-ring Forging Co., Ltd., Dongfeng Forging Co., Ltd.
The main drafters of this Standard include. Zhang Jungai, Zhang Kangsheng, Liyu,
Liubo, Chen Wenjing, Deng Qingwen, Wu Yujian, Chenlin, Wang Guowen, Jiang
Dechao, Jinhong, Zhoulin, Weiwei.
Steel Cross Wedge Rollings - Technological Design Principle
1 Scope
This Standard specifies technological design principle of steel cross wedge rollings
(hereinafter referred to as “rollings”), including technological design, determination of
technological parameters, equipment selection, mold design and quality control.
This Standard is applicable to steel hot rolled parts that are manufactured through the
technology of cross wedge rolling.
2 Normative References
The following documents are indispensable to the application of this Standard. In terms
of references with a specified date, only versions with a specified date are applicable
to this Standard. The latest version (including all the modifications) of references
without a specified date is also applicable to this Standard.
GB/T 8541 Terminology of Forging and Stamping
GB/T 32258 Steel Cross Wedge Rollings - General Specification
3 Terms and Definitions
Terms and definitions that are defined in GB/T 8541 are applicable to this document.
4 Technological Design Principle
4.1 Technological Design
4.1.1 The manufacturing procedure of steel cross wedge rollings mainly includes.
cutting - heating - rolling - hot alignment - thermal treatment - surface cleaning - cold
straightening - sawing of finished product - inspection. The arrangement of the
procedure shall consider the convenience of material flow throughout the whole
manufacturing process; the control of manufacturing cost, the quality requirements
from clients and the condition of equipment, etc.
4.1.2 Casual inspection shall be conducted in each procedure in accordance with
product’s characteristics.
4.1.3 When it is impossible to implement hot alignment, pay attention to temperature
In accordance with product requirements, select corresponding thermal treatment
equipment.
4.3.6 Surface cleaning
Suitable surface cleaning equipment can be selected in accordance with product
dimension, texture, shape, surface quality and processing precision requirement, etc.
4.3.7 Cold straightening
Select suitable equipment to conduct cold straightening on rolled parts with extremely
low straightness accuracy. In addition, eliminate residual stress in accordance with
clients’ requirements.
4.3.8 Sawing of finished product
Toothless saw and band sawing machine can be adopted. When toothless saw is used,
prevent over-burned tissue around the sawed area.
4.4 Mold Design
4.4.1 In the selection of mold parameters, including the forming angle (ɑ) and widening
angle (β), several factors shall be comprehensively considered, such as the
percentage reduction of area (ψ) of rolled parts, length of roll face and avoidance of
product defects, etc. The forming angle shall be selected within the range of 18° ~ 34°;
the widening angle shall be selected within the range of 4° ~ 12°.
4.4.2 Try to make sure cavities on both sides of the mold are the same. In terms of
relatively short axial asymmetrical workpieces, combine 2 or more workpieces to make
them symmetrical, then, start rolling.
4.4.3 Place the side that is not involved in rolling, or the side that manifests slight
deformation, on the end of the rolled parts, so that the loss of head materials can be
reduced.
4.4.4 When the percentage reduction of area is greater than 80%, the design method
of secondary wedge or reduced forming angle can be adopted.
4.4.5 In terms of parts that will easily lead to defects like loosening and hollowness,
increase the forming angle.
4.4.6 In order to decrease spiral mark, a transition fillet R can be designed between
the forming surface and the top surface.
4.4.7 In order to guarantee the rotation of rolled parts, anti-slip mark can be added on
the bevel of the forming angle.
4.4.8 An unloading segment shall be designed on the mold, so that distortion of
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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