目的 制备3Cr2NiMo钢特厚板,解决3Cr2NiMo钢在轧制过程中焊缝易开裂、界面强韧性差、轧后硬度不均匀的问题。方法 在对2块3Cr2NiMo钢预热后,采用真空电子束焊接在5×10-2 Pa的真空条件下对其进行组坯封边,再通过不同的轧制工艺将组合坯复合,后续对坯料进行回火热处理以解决硬度不均匀的问题。结果 随着轧制压下率的增大,复合界面处氧化物的尺寸变小,在70%压下率下,界面已无明显氧化物,界面两侧基体组织均为下贝氏体。在630 ℃下回火3 h随炉冷却后,界面两侧组织较为均匀,复合界面氧化物尺寸有所减小,有助于界面强度的提高。回火后,50%与 70%压下率的板坯沿厚度方向的硬度均为28HRC~32 HRC,满足模具行业的使用要求。回火后,70%压下率试样z向拉伸断裂位置未在界面处,出现了颈缩现象,且为韧性断裂,抗拉强度可达971 MPa,延伸率达到22.5%,冶金结合质量较好。结论 70%压下率的轧制工艺及630 ℃回火3 h后炉冷的冷却方式成功解决了3Cr2NiMo钢界面强韧性差、轧后硬度不均匀的问题。
Abstract
The work aims to fabricate extra-thick 3Cr2NiMo steel plate, in order to solve the problems of weld cracking, poor interface strength and toughness and uneven hardness of 3Cr2NiMo steel during welding. After preheating of 2 pieces of 3Cr2NiMo steel, the blank edges were sealed by vacuum electron beam welding under 5×10-2 Pa vacuum condition, and then the composite billets were combined by different rolling processes. Next, tempering heat treatment was carried out to solve the problem of uneven hardness. With the increase of the rolling reduction rate, the size of the oxide at the composite interface became smaller. At a reduction rate of 70%, there was no obvious oxide at the interface, and the matrix structure on both sides of the interface was lower bainite. After tempering at 630 ℃ for 3 h and cooling with the furnace, the microstructure on both sides of the interface was relatively uniform, and the oxide size of the composite interface decreased, which was conducive to the improvement of the interface strength. After tempering, the hardness of the blank with the reduction rate at 50% and 70% was between 28HRC-32HRC along the thickness direction, meeting the requirements of the mold industry. After tempering, the z-tensile fracture position of the specimen with the reduction rate at 70% was not at the interface and the neck shrinkage appeared, which was ductile fracture. The tensile strength reached 971 MPa and the elongation reached 22.5%, showing good metallurgical bonding quality. The problems of poor interface strength and toughness and uneven hardness of 3Cr2NiMo steel are solved successfully by the rolling process with 70% reduction rate and the furnace cooling method after tempering at 630 ℃ for 3 h.
关键词
真空轧制复合 /
复合界面 /
热轧 /
压下率 /
微观组织
Key words
composite process of vacuum rolling /
composite interface /
hot rolling /
reduction rate /
microstructure
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 李声延, 廖桑桑, 张超, 等. 特厚P20模具钢心部残余奥氏体的控制方法[J]. 江西冶金, 2020, 40(3): 34-37.
LI S Y, LIAO S S, ZHANG C, et al.Control Methods of Residual Austenite in the Core of Extra-Thick P20 Steel Plates[J]. Jiangxi Metallurgy, 2020, 40(3): 34-37.
[2] 王孟超, 武川, 孟亚飞, 等. 基于机器学习模具钢大型锻件力学性能预测[J]. 精密成形工程, 2024, 16(12): 198-208.
WANG M C, WU C, MENG Y F, et al.Prediction of Mechanical Properties of Large Forgings in Mold Steel Based on Machine Learning[J]. Journal of Netshape Forming Engineering, 2024, 16(12): 198-208.
[3] 崔瑞婷, 刘道献, 曹立军, 等. P20预硬塑料模具钢锯切困难原因分析[J]. 模具制造, 2024, 24(1): 89-91.
CUI R T, LIU D X, CAO L J, et al.The Reason Analysis of Processing Difficulties of P20 Preharded Plastic Mold Steel[J]. Die & Mould Manufacture, 2024, 24(1): 89-91.
[4] 吉喆. P20塑料模具钢调质热处理硬度偏高分析[J]. 冶金与材料, 2023, 15(2): 178-180.
JI Z.Analysis of High Hardness of P20 Plastic Die Steel after Quenching and Tempering Treatment[J]. Metallurgical and Materials, 2023, 15(2): 178-180.
[5] YAZDANI M, TOROGHINEJAD M R, HASHEMI S M.Effects of Heat Treatment on Interface Microstructure and Mechanical Properties of Explosively Welded Ck60/St37 Plates[J]. Journal of Materials Engineering and Performance, 2016, 25(12): 5330-5342.
[6] SATYA P V V, MADHUSUDHAN R G. Microstructure and Mechanical Properties of Electroslag Strip and Explosively Clad Low Alloy Steel: Stainless Steel Joints[J]. Transactions of the Indian Institute of Metals, 2012, 65(2): 135-143.
[7] 韩飞, 梁健, 鲍思前, 等. 塑料模具用1.2311预硬化特厚钢板的研制[J]. 特殊钢, 2025, 46(2): 43-47.
HAN F, LIANG J, BAO S Q, et al.Development of Pre-Hardened and Ultra-Thick 1.2311 Steel Plate Used for Plastic Mold Steel[J]. Special Steel, 2025, 46(2): 43-47.
[8] XIE G M, LUO Z A, WANG G L, et al.Interface Characteristic and Properties of Stainless Steel/HSLA Steel Clad Plate by Vacuum Rolling Cladding[J]. Materials Transactions, 2011, 52(8): 1709-1712.
[9] 杨阳. 真空制坯热轧复合法制备45钢、E690钢特厚复合板的工艺研究[D]. 沈阳: 东北大学, 2014.
YANG Y.Study on the Technology of Preparing Extra-thick Composite Plates of 45 Steel and E690 Steel by Vacuum Blanking and Hot Rolling Composite Method[D]. Shenyang: Northeastern University, 2014.
[10] 杨德翰. 真空热轧钛/钢复合板的界面产物演变机理及工艺控制[D]. 沈阳: 东北大学, 2019.
YANG D H.Evolution Mechanism and Process Control of Interfacial Products with Ti-Steel Clad Plate by Vacuum Rolling Cladding[D]. Shenyang: Northeastern University, 2019.
[11] XU S, GAO J H, HUANG Y H, et al.Effect of Hot Rolling Process on the Microstructure and Mechanical Properties of a High-Strength Strip Casting Microalloyed Steel[J]. Materials Science and Engineering: A, 2024, 914: 147130.
[12] KIM M S, PARK K S, KIM D I, et al.Heterogeneities in the Microstructure and Mechanical Properties of High-Cr Martensitic Stainless Steel Produced by Repetitive Hot Roll Bonding[J]. Materials Science and Engineering: A, 2021, 801: 140416.
[13] 邬早勤, 孔令熠, 王磊, 等. 超大尺寸平板硫化机特厚复合钢板开发[J]. 锻压技术, 2024, 49(6): 149-154.
WU Z Q, KONG L Y, WANG L, et al.Development of Extra-Thick Composite Steel Plate for Extra-Large Size Plate Vulcanizing Machine[J]. Forging & Stamping Technology, 2024, 49(6): 149-154.
[14] JANMANEE P, JAMKAMON K, KANCHANASANGTONG T, et al. A Study of Surface Hardness Affecting in Electrical Discharge Machining on AISI P20 Plastic Mould Steel[J]. Advanced Materials Research, 2012, 557/558/559: 1791-1796.
[15] 黄志恒, 张玉栋, 汪雨昌, 等. P20模具钢球化退火工艺研究[J]. 大型铸锻件, 2022(6): 45-48.
HUANG Z H, ZHANG Y D, WANG Y C, et al.Research on Spheroidizing Annealing Process of P20 Die Steel[J]. Heavy Casting and Forging, 2022(6): 45-48.
[16] RANJAN R, MEENA A.Martensite-Austenite Transformation during Dual-Stage Tempering and Work-Hardening Characteristics of Mn-Ni-Mo Steel[J]. Journal of Materials Research and Technology, 2024, 32: 3652-3666.
[17] SUN G J, WANG Q, LI Z G.Microstructural Evolution of High-Nickel Steel during Quenching, Lamellarizing, and Tempering Heat Treatment[J]. Journal of Materials Research and Technology, 2024, 33: 8618-8630.
[18] 国家市场监督管理总局, 国家标准化管理委员会. 塑料模具钢第4部分:预硬化钢板: GB/T 35840.4— 2020[S]. 北京: 中国标准出版社, 2020.
State Administration for Market Regulation, Standardization Administration of the People’s Republic of China. Steels for Plastic Mould: Part 4: Pre-Hardening Steel Plate: GB/T 35840.4—2020[S]. Beijing: Standards Press of China, 2020.
[19] YANG D H, LUO Z A, XIE G M, et al.Effect of Vacuum Level on Microstructure and Mechanical Properties of Titanium-Steel Vacuum Roll Clad Plates[J]. Journal of Iron and Steel Research International, 2018, 25(1): 72-80.
[20] ZHANG X, LUO Z A, YANG J S, et al.Effect of Vacuum Degrees on Interfacial Bonding Behavior of 7050 Aluminum Alloy Clad Plates during Hot-Roll Cladding[J]. Metals and Materials International, 2024, 30(2): 469-482.
[21] 王光磊. 真空热轧复合界面夹杂物的生成演变机理与工艺控制研究[D]. 沈阳: 东北大学, 2013.
WANG G L.Research on Interface Inclusions’ Evolution Mechanism and Process Control of Vacuum Hot Roll Cladding[D]. Shenyang: Northeastern University, 2013.
[22] CHO K S, PARK S S, BAEK S W, et al.SANS-characterized Influence of Degree of Rolling Reduction on the Microstructure of Ti-containing Cold-work Tool Steel[J]. Journal of Alloys and Compounds, 2016, 655: 395-405.
[23] TOJI Y, MIYAMOTO G, RAABE D.Carbon Partitioning during Quenching and Partitioning Heat Treatment Accompanied by Carbide Precipitation[J]. Acta Materialia, 2015, 86: 137-147.
[24] LIU B X, AN Q, YIN F X, et al.Interface Formation and Bonding Mechanisms of Hot-Rolled Stainless Steel Clad Plate[J]. Journal of Materials Science, 2019, 54(17): 11357-11377.
[25] ZHU Z C, HE Y, ZHANG X J, et al.Effect of Interface Oxides on Shear Properties of Hot-Rolled Stainless Steel Clad Plate[J]. Materials Science and Engineering: A, 2016, 669: 344-349.
[26] SHANG S L, LIN S, GAO M C, et al.Ellingham Diagrams of Binary Oxides[J]. APL Materials, 2024, 12(8): 081110.
基金
山东省重点研发计划（2020CXGC010304）
PDF(64299 KB)
渝公网安备 50010702501719号 渝ICP备15012534号-4
