Study of Tools for Hot Rolling of Steel Alloy Tubes
Main problems in roiling of steel alloy tubes are not only heavy mill load and poor ductility of the tube materials but also short tool life. It is, therefore, important to properly choose tool materials and methods of surface treatment in order to obtain longer tool life.
Lives of tool materials such as refractory metal and high alloy steel were investigated on experimental models of a press roll piercer and an elongater. Methods of surface treatment such as electrodeposited composite coating and aluminizing were also tested.
The following results were obtained: (1)high alloy steel with electrodeposited composite coating or aluminizing stood hot wear but deteriorated with sticking in rolling of 18%chromium-8%nickel stainless steel. (2)Molybdenum was the most excellent against hot wear and sticking among the tested materials.
Since molybdenum was expensive, some methods were developed to repair used molybdenum tools by hot isostatic pressing (HIP) and low pressure prasma spray(LPPS). Posibilities of those methods were confirmed on the experimental mills.
KeywordsBoron Nitride Tool Material Molybdenum Oxide High Alloy Steel Alloy Tube
Unable to display preview. Download preview PDF.