钢丝缠绕黑色金属挤压筒的设计  

Design of Steel Wire Wound Extrusion Containers for Steel Hot Extrusion Process

作　　者：刘长勇[1] 张磊[2] 林峰[2] 张人佶[2] 颜永年[2] 康飞宇[1] 

机构地区：[1]清华大学深圳研究生院,深圳518055 [2]清华大学机械工程系北京,100084

出　　处：《机械工程学报》2013年第8期78-83,共6页Journal of Mechanical Engineering

基　　金：国家科技重大专项资助项目(2009ZX04005-021-02)

摘　　要：挤压筒是大口径厚壁无缝钢管热挤压工艺中最为重要的模具,传统的多层组合挤压筒设计方法面临很大挑战。提出采用钢丝缠绕预紧挤压筒的方案,由于钢丝在高温下存在蠕变加速和应力松弛,将钢丝缠绕技术应用于挤压筒的最大问题是解决挤压筒预热与钢丝防护之间的矛盾。针对此矛盾,分析钢丝缠绕挤压筒设计中的关键问题包括预热、钢丝防护和预应力分布控制,提出高温钢锭内置预热和电加热预热两种设计方案,分别分析两种设计方案存在的问题、解决方法和优缺点。针对电加热预热挤压筒,提出新型的热致预应力方法来产生预紧力,将内衬和中衬预热至350℃以上,中衬和外衬之间设有隔热层,经隔热后外衬和钢丝层温度低于80℃,利用两者之间温度差而导致的热膨胀量差值来产生预紧力。基于此想法,设计制造内直径170 mm的挤压筒原理样件,通过温度测试和应力测试,表明所提出的电加热预热挤压筒可达到预期的预紧效果,为挤压筒的设计探讨一种新型的设计方法。Extrusion container is the most important tooling in large steel tube extrusion process. Traditional design approaches such as multi-layered extrusion container would meet great challenges for large extrusion container. Steel wire wound extrusion is proposed. Due to accelerated creep behavior and stress relaxation of steel wire under high temperature, the primary difficulty of applying steel wire winding to the design of extrusion container is to solve the conflict between preheating and protection of the wire from high temperature. The key problems of wire wound containers including preheating, steel wire protection and control of prestress distribution are analyzed. Two solutions to preheating are proposed including hot billet preheating and electrical heating rods. The problems, solutions, advantages and disadvantages are discussed respectively. A novel prestressing method thermal induced prestress is proposed. By preheating the inner cylinder and middle cylinder to over 350 C and keeping the temperature of the outer cylinder and steel wire below 80 ~C, prestress is generated by the difference of thermal expansions due to temperature difference. Based on the idea, a prototype model with the diameter of 170 mm is manufactured. Temperature distribution and pres^ess measurement show that the proposed design could fulfill the requirements and could offer as an alternative to conventional types of extrusion containers.

关 键 词：钢丝缠绕 挤压筒 大口径厚壁无缝钢管 热挤压 

分 类 号：TG375[金属学及工艺—金属压力加工]