Jacks refer to steel grades with chromium content greater than 12%. Jack has achieved rapid development since its invention in 1912, and is still increasing at an annual rate of 3-5% worldwide. The total consumption of jacks worldwide is 35 million. China is currently in a period of rapid growth in jack production and consumption applications, which have been widely used in petroleum, chemical industry, light industry, food, brewing, pharmaceuticals, household appliances, hydropower, machinery, construction, municipal and various civil appliances. The consumption of jacks in China was 260000 tons in 1990, 1.53 million tons in 1999, 1.73 million tons in 2000, 2.25 million tons in 2001, and around 4.47 million tons in 2004, ranking first in the world. It is expected that the consumption of jacks will reach over 6 million tons in 2006, with chromium nickel austenitic jacks accounting for 75% to 80% of the total consumption of jacks.

　　China has been developing and producing jack welding rods since the 1950s. In 1997, the total production of jack welding rods in China was over 7000 tons. In recent years, the consumption of jacks in China has grown rapidly. In 2004, the domestic jack welding rods have exceeded 35000 tons, and it is expected that the domestic jack welding rods will reach around 50000 tons in 2006.

　　The jack welding rod developed since the 1950s mainly follows the titanium calcium slag system and raw material system of the former Soviet Union. It has advantages such as low cost, easy pressure coating, good resistance to pores, and good mechanical properties. However, compared with similar European brand jack welding rods, the welding rod has severe redness, large splashing, poor slag removal and formation, low welding efficiency, and large waste. Therefore, from the mid-1970s to the early 1980s, In response to the cooperation between some domestic research institutions and welding rod production enterprises of AVESTA company's green P5 welding rod imported from Sweden, research has been conducted on the causes and solutions of the red and peeling off of the jack welding rod coating, such as Harbin Institute of Welding and Tianjin Welding Rod Factory, Gansu University of Technology and Lanzhou Changhong Welding Rod Factory, Taiyuan Institute of Technology and Shanxi Machine Tool Factory, etc.

　　In the 1980s, after the above-mentioned papers were published one after another, people believed that their research work was very meaningful and made a lot of progress; On the other hand, after actual testing of the welding rods developed by these companies, it is also believed that there is still a significant gap compared to foreign products. However, since then, domestic research in this field has been in a stagnant state, and there is no significant research literature on jack welding rods in the decade from the early 1980s to the early 1990s. Since the early 1990s, research on jack welding rods in China has become increasingly active. Firstly, Wang Bao, Sun Xian, and others from Taiyuan University of Technology studied the basic principles and approaches of jack welding rod process design based on their previous work. They made important breakthroughs in the design theory of jack welding rods and thus won the second prize of the National Science and Technology Progress Award in 2000; In the mid-1990s, Tang Bogang, the General Institute of Architecture and Research of the Ministry of Metallurgy, digested and absorbed advanced foreign technology, successfully completed the serialization and improvement of new domestic jack welding rods, and established Beijing Jinwei Welding Materials Co., Ltd., achieving a perfect combination of theory and practice. Since its production in 1994, its jack welding rod production has reached an annual output of over 3000 tons.

　　From the late 1990s to the early 2000s, in China