1 Scope
This part of GB/T 3098 specifies the mechanical properties of set screws and similar fasteners not under tensile stress made of austenitic stainless steel, when tested over an ambient temperature range of 10℃ to 35℃. Properties vary at higher or lower temperatures.
This part applies to set screws and similar fasteners:
——with nominal thread diameter 1.6 mm≤d≤24mm;
——of common threads with diameters and pitches in accordance with GB/T 192, GB/T 193 and GB/T 9144;
——of any shape.
It does not apply to screws with special properties, such as weldability.
Note: The designation system of this part can be used for sizes outside the limits given in this chapter (e.g. d>24mm), provided that all applicable mechanical and physical requirements of the hardness classes are met.
This part does not define corrosion or oxidation resistance in particular environments.
Corrosion and oxidation performances and mechanical properties for use at elevated or sub-zero temperatures can be agreed on between the user and the manufacturer in each particular case. Annex D shows how the risk of intergranular corrosion at elevated temperatures depends on the carbon content.
The aim of this part is the classification of corrosion-resistant stainless steel fasteners into hardness classes.
All austenitic stainless steel fasteners are normally non-magnetic in the annealed condition; after cold working, some magnetic properties can be evident (see Annex E).
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 90.3 Fasteners - Quality Assurance System (GB/T 90.3-2010, ISO 16426: 2002, IDT)
GB/T 192 General Purpose Metric Screw Threads - Basic Profile (GB/T 192-2003, ISO 68-1:1998, MOD)
GB/T 193 General Purpose Metric Screw Threads - General Plan (GB/T 193-2003, ISO 261:1998, MOD)
GB/T 230.1 Metallic Materials - Rockwell Hardness Test - Part 1: Test Method (Scales A, B, C, D, E, F, G, H, K, N, T) (GB/T 230.1-2009, ISO 6508-1: 2005, MOD)
GB/T 231.1 Metallic Materials - Brinell Hardness Test - Part 1: Test Method (GB/T 231.1-2009, ISO 6506-1: 2005, MOD)
GB/T 3098.3 Mechanical Properties of Fasteners - Set Screws (GB/T 3098.3-2000, ISO 898-5: 1998, IDT)
GB/T 3098.6 Mechanical Properties of Fasteners - Stainless Steel Bolts, Screws and Studs (GB/T 3098.6-2014, ISO 3506-1:2009, IDT)
GB/T 4334 Corrosion of Metals and Alloys - Test Methods for Intergranular Corrosion of Stainless Steels (GB/T 4334-2008, ISO 3651-1:1998 & ISO 3651-2: 1998, MOD)
GB/T 4340.1 Metallic Materials - Vickers Hardness Test - Part 1: Test Method (GB/T 4340.1-2009, ISO 6507-1:2005, MOD)
GB/T 5267.4 Passivation of Corrosion-resistant Stainless-steel Fasteners (GB/T 5267.4-2009, ISO 16048: 2003, IDT)
GB/T 9144 General Purpose Metric Screw Threads - Preferable Plan (GB/T 9144-2003, ISO 262: 1998, MOD)
3 Designation, Marking and Finish
3.1 Designation
Foreword i
1 Scope
2 Normative References
3 Designation, Marking and Finish
4 Chemical Composition
5 Mechanical Properties
6 Test Methods
Annex A (Normative) Description of the Groups and Grades of Stainless Steels
Annex B (Informative) Austenitic Stainless Steel Composition Specifications
Annex C (Informative) Austenitic Stainless Steels for Cold Heading and Extruding
Annex D (Informative) Time-temperature Diagram of Intergranular Corrosion in Austenitic Stainless Steels, Grade A2 (18/8 steels)
Annex E (Informative) Magnetic Properties for Austenitic Stainless Steels
Bibliography
