GB/T 10051.2-2010 Lifting hooks — Part 2: Technical conditions for forged hooks
1 Scope
This part of GB/T 10051 specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of forged hooks.
This part is applicable to the forged hooks for lifting machinery specified in GB/T 10051.1 (hereinafter referred to as the hooks).
2 Normative references
The following documents contain provisions which, through reference in this part of GB/T 10051, constitute provisions of this part. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document applies.
GB/T 197 General purpose metric screw threads - Tolerances (GB/T 197-2003, ISO 965-1:1998, MOD)
GB/T 223 Methods for chemical analysis of iron, steel and alloy
GB/T 228 Metallic materials - Tensile testing at ambient temperature (GB/T 228-2002, eqv ISO 6892:1998)
GB/T 229 Metallic materials - Charpy pendulum impact test method (GB/T 229-2007, ISO 148-1:2006, MOD)
GB/T 1804 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications (GB/T 1804-2000, eqv ISO 2768-1:1989)
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing (GB/T 29751998, eqv ISO 377:1997)
GB/T 10051.1-2010 Lifting hooks - Part 1: Mechanical properties, lifting capacities, stresses and materials
GB/T 10051.4 Lifting hooks - Part 4: Blanks of shank hook with point
GB/T 10051.5 Lifting hooks - Part 5: Shank hooks with point
GB/T 10051.6 Lifting hooks - Part 6: Blanks of ramshorn shank hooks
GB/T 10051.7 Lifting hooks - Part 7: Ramshorn shank hooks
GB/T 13384 General specifications for packing of mechanical and electrical product
GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition (GB/T 20066-2006; ISO 14284:1996, IDT)
JB/T 5000.15-2007 Heavy mechanical general techniques and standards - Part 15: Non-destructive inspection of forged steel
3 Technical requirements
3.1 Materials
3.1.1 The materials shall be smelted by electric furnace (or converter) and external refining method.
3.1.2 Materials shall meet the requirements specified in GB/T 10051.1-2010, Clause 6.
3.2 Forging and heat treatment
3.2.1 The total forging ratio of the hooks shall not be less than 3.
3.2.2 The dimensions and tolerances of the straight shank single hook blanks (hereinafter referred to as single hooks) shall comply with the requirements of GB/T 10051.4, the dimensions and tolerances of the straight shank double hook blanks (hereinafter referred to as double hooks) shall comply with the requirements of GB/T 10051.6, and the limit deviation of the unnoted tolerance dimensions only allows positive deviation.
3.2.3 After being forged, the hooks shall be heat treated to achieve not less than the mechanical properties specified in GB/T 10051.1-2010, Table 1, and the number of heat treatment shall not be more than 3 times. The forging temperature and heat treatment method of the hooks are shown in Annex B.
3.3 Machining
3.3.1 The dimensions and tolerances of single hooks shall comply with the requirements of GB/T 10051.5, and the dimensions and tolerances of double hooks shall comply with the requirements of GB/T 10051.7. The tolerance grade of the unnoted tolerance dimensions shall comply with the medium m specified in GB/T 1804, and the surface roughness is shown in Table 1.
Foreword I
1 Scope
2 Normative references
3 Technical requirements
4 Test procedures
5 Inspection rules
6 Marking, packaging, transportation and storage
Annex A (Informative) Technical deviations between this part and DIN 15404-1:1989 and their justifications
Annex B (Informative) Forging temperature and heat treatment method of hooks
