1 Scope
This part of GB/T 3098 specifies the mechanical properties of bolts, screws and studs made of austenitic, martensitic and ferritic steel grades of corrosion-resistant stainless steels, when tested at an ambient temperature range of 10℃~35℃. Properties may vary at higher or lower temperatures.
This part is applicable to bolts, screws and studs:
——With nominal thread diameter d≤39 mm;
——Of general purpose thread with diameters and pitches in accordance with GB/T 192, GB/T 193 and GB/T 9144;
——Of any shape.
It is not applicable to fasteners with special property requirements, such as weldability.
Note: The designation system of this part can be used for sizes outside the limits given in this part (e.g. d>39 mm), provided that the property class requirements are met.
This part does not define corrosion or oxidation resistance in particular environments. However, some information on materials for particular environments is given in Appendix E. Regarding definitions of corrosion and corrosion resistance, see GB/T 10123.
The aim of this part is to classify the corrosion-resistant stainless steel fasteners1) into property classes. Some materials can be used at temperatures down to -200℃, some can be used at temperatures up to + 800 ℃ in air. Information on the influence of temperature on mechanical properties is detailed in Appendix F.
Corrosion and oxidation performances and mechanical properties for use at high or sub-zero temperatures can be agreed on between the user and the manufacturer in each particular case. Appendix G shows that the intergranular corrosion risk of carbon content at high temperature depends on the carbon content conditions.
All austenitic stainless steel fasteners are normally non-magnetic in the solid solution condition; after cold deformation machining, some magnetic properties can be evident (see Appendix H).
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 Purpose Metric Screw Threads - General Plan (GB/T 193-2003, ISO 261: 1998, MOD)
GB/T 228.1 Metallic Materials - Tensile Testing - Part 1 : Method of Test at Room Temperature (GB/T 228.1-2010, ISO 6892-1: 2009, 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 3098.1 Mechanical Properties of Fasteners - Bolts, Screws and Studs (GB/T 3098.1-2010, ISO 898-1: 2009, MOD)
GB/T 4334 Corrosion of Metals and Alloys - Test Methods for Intergranular Corrosion of Stainless Steels (GB/T 4334-2008, ISO 3561-1: 1998 & ISO 3561-2: 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 Symbols
Foreword i
1 Scope
2 Normative References
3 Symbols
4 Designation, Marking and Finish
5 Chemical Composition
6 Mechanical Properties
7 Test
Appendix A (Normative) External Thread - Calculation of Stress Area
Appendix B (Informative) Description of the Categories and Groups of Stainless Steels
Appendix C (Informative) Stainless Steel Composition Specifications
Appendix D (Informative) Stainless Steels for Cold Heading and Extruding
Appendix E (Informative) Austenitic Stainless Steels with Particular Resistance to Chloride Induced Stress Corrosion
Appendix F (Informative) Mechanical Properties at High Temperatures and Application at Low Temperatures
Appendix G (Informative) Time-temperature Diagram of Intergranular Corrosion in Austenitic Stainless Steels, Group A2 (18/8 Steels)
Appendix H (Informative) Relative Permeability of Austenitic Stainless Steels
Bibliography
