1. Introduction
Alloy structural steel ( GB 3077-88) is a kind of alloy structural steel formulated by the State Economic and Trade Commission. The standard includes the following grades of alloy structural steel: 15Cr, 20Cr, 30CrMnSiA, 35CrMnSiA, 20CrMnMo, 20CrMo, 30CrMo, 25CrMoV, 14CrMo, 20CrV, 25Cr2MoVA, 30Cr2MoVA, 35CrMnSiA, and 38CrMoAl. The standard generally applies to hot rolled products, cold drawn and cold extruded products, forgings and smelting for carburizing, quenching and tempering.
2. Specifications
Alloy structural steel (GB 3077-88) includes general requirements, size, weight, group number, type of steel, chemical composition, mechanical properties, technical conditions, testing methods, inspection rules, packaging, marking and quality certificates.
2.1 General Requirements
Alloy structural steel (GB 3077-88) shall meet the requirements in terms of surface, shape and size, workmanship, safety and hygiene, and protection devices specified in GB 700.
2.2 Size, Weight, and Group Number
Alloy structural steel (GB 3077-88) is divided into size, weight, and group number for easy management. The size and weight of the steel should meet the requirements of the standard and the production process of the product. The group number should be selected according to the steel grade, material structure, purpose of use and other factors.
2.3 Type of Steel
Alloy structural steel (GB 3077-88) should comply with the requirements of Group A, Group B and Group C in terms of type of steel.
2.4 Chemical Composition
Alloy structural steel (GB 3077-88) should meet the requirements of the standard in terms of Group I and Group II chemical composition.
2.5 Mechanical Properties
Alloy structural steel (GB 3077-88) should meet the requirements of the standard in terms of the mechanical properties of strength, yield strength, elongation and hardness.
2.6 Technical Conditions
Alloy structural steel (GB 3077-88) should meet the requirements of the standard in terms of technical conditions.
2.7 Testing Methods
Alloy structural steel (GB 3077-88) should meet the requirements of the standard in terms of testing methods.
2.8 Inspection Rules
Alloy structural steel (GB 3077-88) should meet the requirements of the standard in terms of inspection rules.
2.9 Packaging
Alloy structural steel (GB 3077-88) should meet the requirements of the standard in terms of packaging.
2.10 Marking
Alloy structural steel (GB 3077-88) should meet the requirements of the standard in terms of marking.
2.11 Quality Certificates
Alloy structural steel (GB 3077-88) should meet the requirements of the standard in terms of quality certificates.
3. Summary
Alloy structural steel (GB 3077-88) is a kind of alloy structural steel formulated by the State Economic and Trade Commission. It should meet the requirements of the standard in terms of surface, shape and size, workmanship, safety and hygiene, and protection devices, size and weight, group number, type of steel, chemical composition, mechanical properties, technical conditions, testing methods, inspection rules, packaging, marking and quality certificates.
