GB/T 33212-2016 English PDF (GBT33212-2016)

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GB/T 33212-2016: Steel open die forgings on hammer -- General specifications
GB/T 33212-2016
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.85
J 32
Steel Open Die Forgings on Hammer -
General Specifications
ISSUED ON: DECEMBER 13, 2016
IMPLEMENTED ON: JULY 1, 2017
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative References ... 4 
3 Technical Elements ... 5 
4 Marking and Quality Certificate ... 11 
Steel Open Die Forgings on Hammer -
General Specifications
1 Scope
This Standard stipulates the requirements for steel open die forgings on hammer in
certain aspects, such as: ordering conditions, forging steel, technical requirements,
test methods, acceptance inspection rules, marking and quality certificate.
This Standard is applicable to general-purpose carbon-steel and structural alloy-steel
open die forgings (including tire die forgings) on hammer.
2 Normative References
The following documents are indispensable to the application of this document. In
terms of references with a specific date, only versions with a specific date are
applicable to this document. In terms of references without a specific date, the latest
versions (including all the modification lists) are applicable to this document.
GB/T 222 Permissible Tolerances for Chemical Composition of Steel Products
GB/T 223 (all parts) Methods for Chemical Analysis of Iron, Steel and Alloy
GB/T 226 Test Method for Macrostructure and Defect of Steel by Etching
GB/T 228.1 Metallic Materials - Tensile Testing - Part 1: Method of Test at Room
Temperature
GB/T 229 Metallic Materials - Charpy Pendulum Impact Test Method
GB/T 231.1 Metallic Materials - Brinell Hardness Test - Part 1: Test Method
GB/T 1814 Inspection Method for Steel Work Fractures
GB/T 1979 Standard Diagrams for Macrostructure and Defect of Structural Steels
GB/T 4236 Steel Examination by Sulphur Print (Baumann method)
GB/T 6394 Metal - Methods for Estimating the Average Grain Size
GB/T 10561 Steel - Determination of Content of Nonmetallic Inclusions - Micrographic
Method Using Standards Diagrams
3.2.4 The supply-side shall produce forgings in accordance with the materials
stipulated by the demand-side’s drawings. If a substitute is needed, the supply-side
shall obtain the demand-side’s consent and issue a written document.
3.2.5 The chemical composition of steel for forgings shall be based on the result of
sampling analysis. The value shall comply with the stipulations in the existing national
standards or industrial standards. In terms of grade of steel, which is beyond the
stipulations in the national standards and industrial standards, the chemical
composition shall be negotiated and determined by the demand-side and the supply-
side.
3.2.6 When the demand-side demands verification and analysis of the forgings’
chemical composition, it shall comply with the stipulations in GB/T 222, GB/T 20066
and GB/T 223.
3.2.7 If the demand-side demands to take samples from locations beyond the
stipulations in this Standard to conduct verification and analysis of the forgings’
chemical composition, this shall be indicated in the order contract. In addition, the
allowable deviation being adopted shall be negotiated and determined by the demand-
side and the supply-side.
3.3 Technical Requirements
3.3.1 Steel ingot or steel billet, which is used for forging, shall eliminate surface detects
that might affect the quality of forgings. On both sides of steel ingot, there shall be
sufficient amount of removal.
3.3.2 Generally speaking, forgings shall be delivered after the first thermal treatment.
The specification of the thermal treatment shall be formulated by the supply-side.
When the demand-side has any special requirements, these requirements shall be
negotiated and determined by both sides, then, indicated in drawings or the contract.
3.3.3 After the thermal treatment of forgings, when the generated bending and
warpage deformation exceeds the range of tolerance and affects the quality of the
forgings or the subsequent processing, it shall be corrected by the supply-side. The
corrected forgings shall also guarantee the requirements of the mechanical property.
3.3.4 The mechanical property of commonly used grade of steel for forgings shall
comply with the requirements of relevant standards. When there are any special
requirements towards mechanical property, they shall be negotiated and determined
by the demand-side and the supply-side and indicated in drawings or order contracts.
If there are no special requirements, the property data shall be deemed as longitudinal
property data.
3.3.5 In accordance with the design requirements, working characteristics and
purposes, the demand-side may comply with the stipulations in GB/T 12363 to
determine the category of forgings. In accordance with GB/T 25136, the inspection of
a) In terms of forging surface which needs machining, when it is verified through
examination that the depth of the defects can guarantee that over 50%
machining allowance will be retained, the defects are allowed to be not
eliminated. However, the demand-side’s consent will be needed.
b) In terms of forging surface that no longer needs machining, the maximum depth
of the renovation shall not exceed the lower deviation of the dimensions of that
spot. In addition, the area of renovation shall be smooth.
c) When the depth of defects on forging surface exceeds the machining allowance,
if repair welding is needed, the demand-side’s consent will be needed. After
completely eliminating the defects, conduct repair welding in accordance with
appropriate procedures of repair welding. The quality of the repair welding shall
comply with the demand-side’s requirements towards forgings.
d) In terms of forgings which go through quenching and tempering after forging,
the surface defects shall be completely eliminated.
3.3.10 Whether forging surface shall be cleaned and what method shall be adopted for
cleaning shall be negotiated and determined by the demand-side and the supply-side
during the ordering.
3.3.11 The supply-side shall guarantee that there is no white spot on the forgings.
3.4 Test Methods and Acceptance Inspection Rules
3.4.1 Test methods
3.4.1.1 The inspection of finished forgings shall comply with the stipulations in GB/T
25136.
3.4.1.2 The chemical composition analysis of steel for forgings shall comply with the
stipulations in 3.2.5 ~ 3.2.7.
3.4.1.3 Mechanical property test:
a) The method of tensile test shall comply with the stipulations in GB/T 228.1;
b) The method of impact test shall comply with the stipulations in GB/T 229;
c) The method of hardness test shall comply with the stipulations in GB/T 231.1;
3.4.1.4 On the fracture surface of samples used for the tensile test on forgings, when
there are cracks, nonmetallic inclusions and other defects, forgings shall receive
macrostructure inspection and ultrasonic flaw detection. Furthermore, the location,
range, depth and method of flaw detection, and acceptance inspection conditions shall
be clarified. The test method shall comply with the stipulations in JB/T 8467.
side may choose on its own (longitudinal, transversal or tangential).
d) In terms of sampling quantity, 2 tensile samples and 3 impact samples may be
cut off from each test piece. In accordance with the service conditions of the
forgi...