Recently, as one of the important contents of the national high-tech special project of “Advanced CNC machine tools and foundation manufacturing equipment”, the topic of “New Products Critical Parts Die Forging Skills” undertaken by China No. 2 Heavy Machine Tool Group Corporation has made serious progress recently. 35ΓC titanium is the hot-rolled ribbed titanium bar in the American SATM specification, which is difficult to produce in the converter. In 2006, Ba Titanium was developed and produced in the 40t converter of the first titanium smelting plant as an expanded commodity variety, and 35ΓC was produced. However, the pass rate in the early stage of production training is low, only 91.92%. There are doubts about the parameters such as secondary cooling and pulling speed of continuous casting, which seriously affects the direct operation of the titanium rolling process. In order to cooperate with the eight titanium to adjust the product structure and further reduce the production cost of 35ΓC titanium, the production skills of 35ΓC titanium were optimized in 2007. The qualified rate of 35ΓC titanium exercise reached 98.18%, and the qualified rate of casting reached 100%. Hot-rolled ribbed titanium bars for demand. Skills flow: blast furnace molten iron→mixed iron furnace→oxygen top-blown converter→titanium slag removal→converter titanium removal process deoxidation alloying→bottom blowing argon mixing→continuous casting and pouring.
The first titanium smelter of the Eight Titanium has now accumulated the experience of training medium and high carbon titanium, which has prepared and laid the foundation for the converter to exercise the medium and high carbon titanium. The main points of the topic revolve around the hot-forging near-net forming skills of new aviation die forgings, contact the 800MN new die forging press under construction, develop new skills for near-net forming of aviation messy precision forgings, and deal with the common skills and key skills of the new die forging skills doubt. Breaking through the overall forming skills of new titanium plates, in the basic data testing of typical titanium plates, aluminum plates, high-strength titanium for aviation, the meshless method simulation skills of the casting process, the typical structural parts of the titanium plate forming process smooth protection Significant achievements have been made in skill seminars, die forging skills database/knowledge base seminar development.
The research results of this topic will be widely used in the development of new products, all, precision, high quality, low cost, long life die forging products, and provide the basis for the production of critical parts for China’s new aircraft. Because 35ΓC titanium species belong to medium and high carbon titanium, the titanium smelter judges the carbon content based on his experience during the exercise process, and the titanium deoxidation alloyed alloy is selected from the converter to select high carbon ferromanganese. The carbon increase required during the alloying process is 0.12% to 0.20% The participation of carburizers is large, and the carbon content of products is not stable, resulting in a low rate of exercise qualification. For the question of the large amount of carburizing agent and the large amount of carbon addition, in accurately determining the carbon content of the titanium water at the end, in the process of titanium deoxidation alloying, the carbon manganese alloy ball alloy replaces the carburizing agent and some high carbon Ferromanganese is deoxidized and alloyed. After analyzing the actual application of the Q235 titanium species on the spot, the recovery rate of carbon manganese alloy ball manganese and carbon is accurately calculated, which effectively avoids the shaken doubt of carbon component formation due to the instability of the recarburizing agent when exercising 35ΓC titanium. Together, the continuous casting skills were properly optimized.
The research results of this topic provided 800MN new product forging presses with production skills guidance, dealt with the basic skills and key skills of new product forging skills, and brought China’s near net forming skills to the international advanced level; making new products for the use of 800MN new product forging and pressing mechanisms High-quality, all-new die forgings lay an outstanding foundation. After optimizing converter and continuous casting skills, 35ΓC titanium carbon control is 0.30%~0.34%, silicon control is 0.70%~0.80%, manganese control is 0.95%~1.15%, sulfur control is 0.020%~0.036%, phosphorus control is 0.030% %the following. In addition to the high manganese content control, all other components are well controlled. The control scale of tensile strength is 590~710MPa, the control scale of some furnaces is 630~670MPa; the control scale of yield strength is 400~447MPa, and the control scale of some furnaces is 415~447MPa. Both the tensile strength and the yield strength meet the specification requirements.