预热对中高碳钢堆焊冷却温度场和应力场影响的数值模拟  

Effect of preheating on temperature and stress fields of medium-high carbon steel in hardfacing process by numerical simulation

作　　者：臧新良[1] 刘利刚[1] 王玉辉[1] 钱玉 杨庆祥[3] 

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004 [2]秦皇岛北方管业有限公司,河北秦皇岛066004 [3]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066004

出　　处：《材料热处理学报》2013年第10期187-192,共6页Transactions of Materials and Heat Treatment

基　　金：河北自然科学基金(E2012203019);河北省百名优秀人才支持计划(SPRC021)

摘　　要：分别测定了无预热条件下60CrMnMo钢堆焊试样冷却过程的温度场和残余应力场,采用有限元方法建立了二维有限元模型,对其进行了数值模拟,在此基础上,采用此模型模拟了预热温度为200℃条件下试样在堆焊冷却过程中温度场和不同时刻的应力场,特别是考虑了不同截面上关键点发生马氏体相变时的应力变化情况。结果表明:60CrMnMo钢试样堆焊后的温度场与残余应力场的模拟结果与实测结果吻合较好,证明了所建模型的有效性;经200℃预热后,在堆焊初期,试样中心部位温度较高,其余部位近似为200℃,冷却到30 s后,试样中心部位急剧降温,冷却到180 s后,整个截面的温度分布趋于均匀;最大拉应力出现在热影响区,而不是堆焊区;当发生马氏体相变后,热影响区的拉应力急剧增大,直至与平衡状态时的拉应力值相当。预热降低了堆焊试样热影响区的最大拉应力,从而减少了堆焊开裂倾向。The temperature and residual stress fields of the hardfacing metal without preheating were measured in hardfacing cooling process, which were simulated by finite element （FE） model simultaneously. Based on the mentioned above, the temperature and stress fields of the hardfaeing specimen preheated at 200 ℃ were simulated. Specially, the stress changes of the key points at different sections were considered when martensite transformation occurred. The results show that the measured results of the temperature and residual stress fields of the hardfacing metal without preheating fit close to the simulated ones, which proves that this model is effective. When the specimen is preheated at 200 ℃ , the temperature at the specimen center is high at initial stage, while, it is 200 ℃ at others. When cooling time is 30 s, the temperature at the specimen center is decreased sharply. When the time is 180 s, the temperature at all sections of the specimen is distributed uniformly. The largest tensile stress appears at heat affected zone （HAZ） , in stead of hardfacing zone. When martensite transformation occurs, the tensile stress increases sharply. The largest tensile stress at the specimen center can be decreased by preheating, which reduces the cracking tendency of hardfacing metal.

关 键 词：堆焊 数值模拟 温度场 应力场 马氏体相变 

分 类 号：TG142.31[一般工业技术—材料科学与工程]