摘要
焊接接头的强度匹配方式对接头的设计、制造工艺、裂纹敏感性以及破坏行为有重要影响,焊缝金属、母材、焊接接头的强度分布以及焊接接头强度匹配系数的分布是焊接结构强度、寿命和可靠性计算的基础。通过对12Ni3CrMoV钢焊接接头强度匹配系数分布的研究,提出低强匹配焊接接头的界定方法,强度匹配系数的均值小于95%、强度匹配系数的均值加上其标准差应小于100%,并且强度匹配系数大于105%的概率应小于3%。计算结果表明,12Ni3CrMoV钢焊接接头低强、等强、超强匹配概率分别为85.44%、11.85%和3.35%,低强匹配特征明显,强度匹配系数的均值位置非常合理。但由于母材强度的标准差较大,约为焊缝金属强度标准差的1.56倍,是造成强度匹配系数低于低强匹配下限值86%的概率高达7.79%和强度匹配系数高于105%的概率超过3%的主要原因。此外,这也是低强匹配焊接接头中出现冷裂纹的主要原因之一。
The weld strength matching of welded joint plays an important role in design, manufacturing procedure, cracking sensitivity as well as fracture behavior of welded joint. In order to analyze strength, fatigue life and probability of welding structure, it is essential to analyze the strength probability distribution of base metal, weld metal, welded joint as well as welded joint strength matching coefficient. Based on the research of strength matching coefficient of 12Ni3CrMoV steel welded joint, a sorting method of under-matching form has been put forward. That is： the mean value of strength matching coefficient should be less than 95% ; the mean value of strength matching coefficient plus its standard deviation should be less than 100% ; and the probability should be less than 3 percent, where strength matching coefficient is larger than 105%. The result shows that the probabilities of under matching, even matching and over matching are 85.44%, 11.11% and 3.35% respectively. Therefore, the under matching character of the welded joint is prominent and the mean value of strength matching coefficient is appropriate. However, the strength standard deviation of the base metal is bigger, which is about 56 percent more than that of welded metal. It is the main reason that the probability is up to 7.79 %, where strength matching coefiqcient is under 86% which is the lower limit of the under matching, and the probability up to 3.35%, where strength matching coefficient over 105%. Beside, it is one of the main reason that the cold cracking appears in under matching welded joint.
出处
《机械强度》
EI
CAS
CSCD
北大核心
2006年第3期453-457,共5页
Journal of Mechanical Strength
关键词
焊接接头
强度匹配
强度分布
界定
数理统计
Welded joint
Strength nmtch
Strength distribution
Sorting
Statislics
