Li Xun

Li Xun

Li Xun (1913.11.20-1983.3.20), born in Shaoyang, Hunan Province, is a physical metallurgist and one of the pioneers of Metallurgical Science and technology in China.

He graduated from Hunan University in 1936 (the 25th year of the Republic of China). He received a Ph.D. in 1940 (the 29th year of the Republic of China) from the school of metallurgy, Sheffield University, UK. He received a Ph.D. in 1950. He joined the Jiusan Society in 1953. He was elected as an academician of the Chinese Academy of Sciences in 1955 and joined the Communist Party of China in 1961.

In his early years, Li Xun was engaged in the study of hydrogen in steel, which laid a scientific foundation for the study of hydrogen in steel. He founded the Institute of metals, Chinese Academy of Sciences. In the study of the reasons for the fracture of the main shaft of an aircraft engine, the mystery and law of hydrogen embrittlement in steel are found. It is proved that the internal cracking of steel is caused by the existence of hydrogen. The relationship between the size and time of steel and the hydrogen content in steel at different temperatures is clarified by means of diffusion, solubility and structure of steel. It has a great influence on the steel technology all over the world.

Life of the characters

On November 20, 1913, Li Xun was born in Jingtou village, Renfeng Township, Shaoyang County, Hunan Province. My grandfather was a Juren in the former Qing Dynasty. His father was a Gongsheng in the former Qing Dynasty. He was a classmate with CAI E. in the early years of the Republic of China, he worked as a magistrate of Nanchang County in Jiangxi Province. Li Xun was enlightened in Nanchang provincial No.3 primary school when he was less than 6 years old. He graduated from primary school in 1925. In 1927, he graduated from Changsha Changjun Middle School and was admitted to yueyun middle school. In 1932, he passed the senior high school graduation examination with the first place, and was promoted to the Department of mining and metallurgical engineering of the school of mining and metallurgical engineering of Hunan University without examination. He won the scholarship for consecutive years. In 1936, he graduated from the university with a bachelor's degree in engineering. He served as a teacher of Changsha Chuyi technical school and did geological survey work. In 1937, Hunan Province held an examination for studying abroad at public expense. Li Xun applied for the examination and ranked first. In September of the same year, he went to the school of metallurgy of Sheffield University of England for further study. In 1940, he received a Ph.D. from the school and applied to stay in the University for research. from 1940 to 1951, he worked in the Graduate Department of Metallurgy College of Sheffield University, UK, guiding some graduate students. During 1942-1948, he published a series of valuable papers on the research of hydrogen in steel, which laid a scientific foundation for the further research of hydrogen in steel and made outstanding contributions in theory and practice. In 1946, the Chinese national government once instructed Professor SA Bentong, director of Academia Sinica, to invite Li Xun to return to China to take up his post. He declined. In 1950, Sheffield University awarded Li Xun a doctorate in metallurgy. In the UK, the university is the only institution to name its advanced doctorate with a doctorate in metallurgy. Li Xun is the only scholar in China who has won this award. During his work in Sheffield University, Li Xun mainly engaged in the study of hydrogen embrittlement in steel. In August 1950, Li Xun returned to China via Hong Kong. At the invitation of Qian Sanqiang, director of the Planning Bureau of the Chinese Academy of Sciences, he returned to China to prepare for the establishment of the Institute of metallurgy. On August 6, 1951, the Chinese Academy of Sciences immediately established the preparatory office for the Institute of metals of the Chinese Academy of Sciences with Li Xun as its director. In the winter of 1951, Li Xun and his party went to the northeast to explore the site and set foot on the wulihezi in the southern suburb of Shenyang, which was agreed by the Northeast People's government. On February 16, 1956, scientists in natural sciences and Technological Sciences gathered in Beijing to work out the national 12 year long-term development plan of natural sciences. Li Xun was the convener of Metallurgical Science and technology, and participated in the work of the comprehensive group to plan the development blueprint of China's metallurgical industry. Since the establishment of the State Science and Technology Commission, he has repeatedly planned the development of science and technology across the country. He is responsible for metallurgy. Later, he served as the deputy leader of the metallurgical professional group and Metallurgical new materials group of the State Science and Technology Commission, and the leader of the high temperature testing group and aviation materials group, which lasted for more than 20 years. In 1956, the state compiled the outline of the 12-year long-term development plan of natural science, and Li Xun presided over the metallurgical science and technology section, planning the development blueprint of China's metallurgical industry. In 1957, he returned from his visit to the Soviet Union. Considering the need of developing jet and aerospace technology, the development of high temperature and high strength is the trend of metal and alloy materials, so he decided to focus on the research fields of superalloys. When the research on Wrought Superalloys reached a certain stage, it was difficult to make further progress in production and properties, and he proposed to adopt the precision casting process to research and manufacture high strength superalloys Warm alloy turbine blades. In 1960, with the active promotion and personal participation of Li Xun and Ge tingsui, a national class on dislocation and electron theory was held in Changchun, and then a National Symposium on metal physics was held in Shenyang, which was an important event in the progress of metal physics in China. Since 1962, the state has repeatedly invited experts to plan the development of science and technology in the country. He is responsible for metallurgy. In 1965, the State Science and Technology Commission set up a leading group for the application of rare earth and niobium in steel. He served as the group leader and held many academic conferences, which promoted the relevant research work in China. He joined the Communist Party of China on December 20, 1961. In 1962, he repeatedly planned the development of China's Metallurgical discipline, and served as deputy group leader of metallurgical specialty group and Metallurgical new materials group of State Science and Technology Commission, group leader of high temperature testing group and aviation materials group, and group leader of leading group for application of rare earth and niobium in steel. The pioneering research on steel manganese alloy has been carried out, which contributes to the development of low-temperature non-magnetic and heat-resistant steel in China. In May 1978, the Chinese Academy of Sciences established the Shenyang branch and appointed Li Xun as its president. In early 1983, Li Xun made a comprehensive survey of China's newly built metallurgical industry in order to explore new ways for scientific research institutes to better develop metallurgical industry. Shortly after returning to Beijing from Baoshan Iron and steel works, he went to Panzhihua Iron and steel company, Changcheng iron and steel company, Wuhan Iron and steel company and other places for investigation. During the investigation, he passed away in the early morning of March 20, 1983 when passing through Kunming.

Main achievements

Achievements in scientific research

During 1938-1950, the research work was mainly about the quality of alloy steel and the cold workability of steel. A series of research work has been done on the problem of hydrogen in steel. An instrument for measuring the solubility of hydrogen in steel has been designed and made. The hydrogen cracking phenomenon in steel has been found by using this instrument. The mechanism of hydrogen cracking in alloy steel has been explained comprehensively with convincing experimental data, and the solutions and related process parameters have been put forward. From theory to practice, the problem of white spot (internal crack) in steel was solved, which was applied in industry and contributed to the British military alloy steel industry at that time. In the 1940s, under the guidance of Professor Anju of Sheffield University, Li Xun was engaged in the research of hydrogen in steel. During the Second World War, there was a sudden rupture of British aircraft. Li Xun studied hard and found that hydrogen in steel was the main cause of the accident. He also found out the law of incubation period and dehydrogenation of white spots in steel, which solved the long-standing problems. Li Xun et al. Found out the relationship between hydrogen content and mechanical strength of steel and cracking, that is, when the hydrogen content in 100 grams of steel reaches 2 ml, the plasticity of steel can be reduced. However, the hydrogen content of steel produced at that time was as high as 4-6 ml, so hydrogen embrittlement of steel was difficult to avoid. The hydrogen content of steel causing cracking is generally high. The diffusivity and solubility of hydrogen in steel are two important factors for the occurrence of cracking. Li Xun et al put forward a theory, that is, the internal pressure caused by the accumulation of hydrogen near the defect leads to cracks. The formation of this pressure is due to the diffusion of atomic hydrogen to defects at high temperature and the transformation of atomic hydrogen into molecular hydrogen at room temperature. These molecular hydrogen can't diffuse, so huge internal pressure is produced, which makes the steel crack. When carbides exist, hydrogen reacts with carbides to form methane, and the pressure is enough to produce cracks. During cold working, defects are formed, which increases the content of molecular hydrogen and promotes the initiation of hydrogen embrittlement. From 1942 to 1948, Li Xun published a series of valuable papers on the research of hydrogen in steel, which laid a scientific foundation for the further research of hydrogen in steel and was praised by people. In the late 1950s, Li Xun led the Institute to make a great change in its research direction. From serving the iron and steel industry to developing new materials, new technologies and corresponding new testing methods. He quickly organized forces to build research laboratories for superalloys, refractory metals, cermets, uranium metallurgy, uranium dioxide ceramic nuclear materials, pyrolytic graphite, etc., and strengthened manpower for the research of high strength steel and alloy steel. In a relatively short period of time, he achieved remarkable results. The Institute of metals has made important contributions to the successful development of some key materials for China's first atomic bomb, the first man-made satellite to return to the ground, the first supersonic jet aircraft and the first nuclear submarine.

personnel training

Li Xun attaches great importance to intellectual development and talent training. In order to set up the Institute, Li Xun made great efforts to attract talents. He first invited Zhang Peilin, Zhang Zuomei, Zhuang Yuzhi, Fang Bing, Ke Jun, etc. from those studying in the UK. He also invited Mr. Ge tingsui, Mr. He Yizhen, Mr. Zhang Shouqing, Mr. He Yizhen, Mr. Zhang Shouqing, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr. Li Xun, Mr Tan Bingyu, Liu Jingyi, Liang Shuquan and other senior researchers. Li Xun took the initiative to unite them sincerely and give full play to their talents. In the mid-1950s, scholars from abroad, such as Shi Changxu, Guo Zhongxin, Si Chongyao, Wu Dingming and so on, came to work as researchers under the courtesy of Li Xun and made outstanding contributions in their respective academic fields

Chinese PinYin : Li Xun