Research and Practice on Improving the Quality of TE-30 Export Leaf Spring
The scientific knowledge of metal materials is widely used in many aspects such as material development, smelting, rolling, etc. in metallurgical enterprises, which is well known by most people. The author has been engaged in the design, processing and manufacturing of mechanical products in metallurgical enterprises for many years. Through many years of participation in the development of new steel grades and the practice in the processing of mechanical products, I believe that any good material will have some shortcomings. In this process, it is crucial to maximize the potential advantages of materials and avoid their shortcomings. If this work is done well, it will bring huge economic benefits to the enterprise and at the same time greatly improve the performance of the product.
This article discusses the above point of view with the practice of applying 28MnSiB low carbon spring steel to the export variable cross-section single leaf spring TE-30.
28MnSiB low-carbon spring steel is a new type of spring steel developed by Shougang Company in the early 1980s. It is a steel grade obtained by appropriately increasing some carbon content and adding trace element boron on the basis of grade Ⅲ rebar steel 25MnSi. Because it is a low-carbon spring steel, its substructure is dislocation martensite, which has considerable strength and good toughness, so the mechanical properties of this steel basically reach the performance of 60Si2Mn . In addition, because under the same yield condition, the fracture toughness of dislocation martensite is much higher than that of twin martensite , and the steel has a higher fatigue limit than 60Si2Mn after natural aging , Therefore, it has a higher fatigue life than 60Si2Mn during use.
In recent years, due to the increasing export quality requirements of TE-30, the product has entered the loading market from the maintenance market, and the output has also increased significantly. In addition to importing some billets from Shougang Iron and Steel Company and selecting them for export, we also imported 88 billets from Tangshan Iron and Steel Company that were cast by electric furnace smelting molds and then opened, and we have done a lot of work.
1. Increase hardenability test work, and classify material size according to hardenability
2. Reasonably adjust the process to improve the fatigue life and surface quality of the leaf spring
3. Applying reliability theory to achieve fatigue life quality assessment in line with international standards
In summary, Hongye Steel’s export leaf spring TE-30 has conducted an objective and realistic assessment of the shortcomings of past products and processes through the use of scientific knowledge of metal materials in the past year, and started from the selection of materials. A series of improvements from craftsmanship to inspection procedures have improved the product quality to a great extent and won praise from American customers. At the same time, it has laid a better foundation for our future work.
About the Author
Wang Jun is currently the chief engineer of the leaf spring branch of Beijing Shougang Hongye Steel Plant and a senior engineer of metal materials and heat treatment. Currently a member of the National Spring Standardization Technical Committee.
From January 1979 to January 1983, Bachelor of Engineering, majoring in metal materials and heat treatment at the First Branch of Beijing University of Iron and Steel;
In March 1983, he was assigned to Shougang Hongye Steel Plant, mainly engaged in product development and daily process management of automobile leaf springs;
In 1989, he served as Deputy Chief of the Technical Development Section of Shougang Hongye Steel Plant;
In 1990, he served as the chief of the technical development section of Hongye Spring Plant of Shougang Machinery Corporation;
In 1992, he served as deputy director of the Leaf Spring Research Institute of Shougang Hongye Spring Plant.
From 1993 to 1998, he worked on the development of new leaf spring products in the technical department of Shougang Hongye Steel Plant.
From October 1998 to now, he is the chief engineer (chief engineer) of the leaf spring branch of Shougang Hongye Steel Plant. Undertake the review work of new product development of leaf spring and related new product development and scientific research work.
During the “Sixth Five-Year Plan” period, he participated in the research and development of 28MnSiB new low-carbon spring steel, and at the same time participated in the research and development of the changeable plate spring. The National Science and Technology Commission and the Ministry of Metallurgy issued a major achievement award.
Since 1984, we have conducted technical negotiations with foreign companies for many times, designed and developed a variety of export leaf springs, and exported them to the United States, Canada and the United Kingdom in large quantities, and achieved good economic benefits. At the same time, due to long-term work on the front line of production, we have accumulated a lot of experience in handling problems on site. It has been awarded many times by the relevant departments of Shougang Corporation for foreign exchange earning.
From 1998 to 1999, because the hardenability test was successfully applied before the leaf spring is rolled into a product, a large number of waste products caused by poor hardenability of the material were avoided, and the best operator of Shougang Corporation was obtained. Won the third prize for best practices.
In 2000, due to the successful design and development of the leaf springs required for the Guangzhou New Gymnasium (the project of the Ninth National Games, the closing ceremony was held here), it was awarded the honorary title of economic and technological innovation model by the Beijing Federation of Trade Unions. This kind of leaf spring has been used in the construction industry for the first time in the world. It was registered by Xu Guobin, a professor at Northern Jiaotong University (doctoral supervisor, member of the expert group of China Steel Association, director of China Steel Association Space Structure Association, national level one) The structural engineer) proposed that Tongji University put forward the technical parameters, and I completed the entire process from design to production and inspection.