GB/T 42602-2023 (English Version)

Standard No.: GB/T 42602-2023
Language: Chinese, Available in English version
Release Date: 2023
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 42602-2023

Scope: This document specifies the use of forging equipment and accessories for forging large steel forgings, steel ingot manufacturing, forging process, forging operation, risk control of the forging process, records and inspection requirements. It is applicable to the forging of large steel forgings with ingot weight greater than or equal to 150t and single forging weight greater than or equal to 90t. The main materials include Ni2, Ni3, Ni4 series rotor materials, Cr2, Cr3, Cr4 series support roller materials, 12Cr2Mol and 12Cr2MolV container materials, and 20MnNiMo nuclear power materials. Large steel forgings made of other materials can also be forged with reference to this document.

Introduction

1. Background and purpose of the standard

GB/T 42602-2023 "Forging Specifications for Large Steel Forgings" aims to standardize the forging process and quality requirements of large steel forgings to ensure the high performance and reliability of the products. This standard applies to large forgings with a weight of ≥150t or a single forging weight of ≥90t, covering Ni series, Cr series and nuclear grade materials.

2. Comparison of key technical parameters

Technical indicators	Requirements for shaft parts	Requirements for cylindrical parts	Requirements for pie-shaped parts
Ingot utilization rate	55%～70%	58%～75%	55%～70%
Total forging ratio requirement	≥3.0	≥5.0	≥3.5

3. Practical application case analysis

Take Cr3 support roller as an example, its total forging ratio requirement is ≥5.0. Through multi-fire forging processes (including upsetting, drawing and expansion), the uniformity of microstructure and mechanical properties of forgings are ensured.

4. Technological evolution and innovation

Compared with the old standard, GB/T 42602-2023 introduces more advanced forging methods, such as compact forging method and center tensile stress-free forging method. These technologies significantly improve the internal quality of forgings by optimizing the deformation stress state of the core.

5. Implementation suggestions

Equipment selection:Select a forging hydraulic press with a nominal force ≥100MN and equip it with online dimension measurement and scratch cleaning equipment.
Process optimization: Formulate heating specifications according to material characteristics to ensure that the initial and final forging temperatures are controlled within a reasonable range (see Appendix B).
Quality control: Strengthen temperature monitoring and dimension inspection during the forging process to ensure that forgings meet the requirements of GB/T 37775.
Staff training: Regularly provide technical training to operators to improve safety awareness and operating skills.

GB/T 42602-2023 Referenced Document

GB 13318 General rules for safety and environmental conservation of forging production
GB/T 36484 Metalforming machinery—Terminology
GB/T 37775 Heavy steel open die forgings—General technical specification
GB/T 8541 Terminology of forging and stamping
GB/T 9452 Test method for qualified work zone of heat treatment furnace

GB/T 42602-2023 history

2023 GB/T 42602-2023 Specification of forging of heavy steel forgings