特大型零件热态成形制造技术基础研究

在中国国家自然科学基金重点项目《特大件成形制造技术基础研究》、国家科技支撑计划课题《大型轧机共性技术》、国家重点基础研究发展计划(973计划)前期研究专项《大型零件热态成形制造虚拟技术基础研究》，以及中国河北省科技攻关项目《大型轧机共性技术》和《特大件成形制造技术基础研究》共同资助下，以大型锻钢轧辊(辊身直径超过1 000 mm或质量大于100 t)为对象，通过宏观 微观强耦合建模，解决铸造缺陷信息遗传、孔洞锻合条件、形变焊合条件、材料断裂准则构建，以及热 力 微观组织耦合建模等关键技术问题，建立以淬硬层深度数值预测技术为核心的热处理工艺分析与优化系统，提出基于非均质轧辊辊间接触力学模型的轧辊强度设计方法，构建起大型锻钢轧辊热态成形制造与服役评估的多学科耦合决策支持理论体系，提出理论研究报告。针对缩孔和气孔等大型铸钢锭铸造中的孔洞缺陷控制，以大锻件内部孔洞锻造闭合过程为科学问题，以大锻件内部有效锻合区域数值预测为目标，将有限元方法与人工神经网络技术相结合，利用神经网络的非线性映射能力，描述材料变形抗力、温度、应力应变与孔洞闭合程度之间的复杂关系，将孔洞锻合过程有限元模拟结果作为神经网络训练样本，建立起温度、应力和变形等多场耦合作用下的孔洞锻合条件模型(VCCM)。针对孔洞形变焊合机理与物理模拟模型一致性问题，以消除大锻件心部残留微孔隙，实现物理闭合状态下的锻合孔洞缺陷的真正冶金结合为目标，基于临界闭合孔洞界面接触力学原型和原子高温扩散理论，以界面接触应变和高温环境作为孔洞焊合的驱动力，利用高温和大变形对闭合孔洞界面扩散焊合的有利影响，提出适用于大锻件在锻造成形阶段的内部孔洞缺陷形变的形变焊合方法，通过物理模拟实

Basic Research on Hot Forming and Manufacturing Technology of Super Large Parts

This study is supported by the key project of National Natural Science Foundation of China“Basic Research on Forming and Manufacturing Technology of Super large Parts”, the key project of State Science and Technology Support Program“Research on Generic Technology of Heavy Mill”, the early stage special research of National Key Program for Fundamental Researches (Grant No.973)“Basic Research on Hot Forming and Manufacturing Virtual Technology of Large Parts”, the critical scientific and technological project of Hebei Province“Basic Research on Forming and Manufacturing Technology of Super large Parts”and“Research on Generic Technology of Heavy Mill”. Taking large forged steel rolls (the diameter of the body of roll is over 1000mm or the quality is over 100t) as the research object, this study has established macroscopic microscopic close coupled model to solve the key technical issues such as inheritance of casting defects information, void closure condition, deformation welding condition, materials fracture criterion creation and thermal stress coupled modeling of microstructure, established the heat treatment process analysis and optimization system centering on numerical prediction of hardened depth, proposed the roller strength design method based on contact mechanics model between heavy rollers made of heterogeneous material, built up a multi discipline coupled theoretical framework for hot forming manufacturing and service assessment of large forged steel rolls, and brought forward theoretical research report.