Skid Button For Heating Furnace

The skid button(rider) is an important component of the beam of the heating furnace, which is not only subjected to high temperature radiation, but also loaded by the steel billet. It must have high temperature compressive strength, high temperature oxidation resistance, slag resistance, quenching and heating resistance and high temperature creep resistance. Our technical team selects high-quality raw materials to produce skid buttons in different areas according to the work characteristics of different heating furnaces. Our skid buttons products of the same grade have a longer service life than other products of the same grade.

Understanding the Real Failure Reason of the Heating Furnace Skid Buttons to Increase its Working Life.

The material of the heating furnace skid buttons is selected according to the furnace temperature and working condition.

1. The preheating section generally uses ZGCr25Ni20Si2.

2. The first heating section generally uses 20% Co.

3. The second heating section and soaking section generally use 50%Co or 40%Co.

Based on many years' research and on-site observation, our technical team believes that the main reason for the damage of skid button is not wear, ablation and oxidation. The main reason for the damage of skid button is crushed by the billets.

The continuous casting billet has a certain degree of deflection or side bending. The side bending of a continuous casting billet of 8 to 10 meters is about 50mm, which means that not all the skid buttons in the heating furnace are under pressure. Even the skid buttons in contact with the billet are not stressed across the entire working surface.

However, the designer considered that all the skid buttons were under pressure. Because the pressure of the skid buttons exceeded its maximum strength, the surface of the skid buttons was plastically deformed to form pits, and the scale of the steel billet fell off in the pits and quickly grew large, resulting in the formation of bumps on the surface of skid buttons.

Our New Material Could Effectively Increase the Working Life of the Skid Buttons

The melting points of traditional materials for skid buttons(50%Co, 40%Co, 20%Co, etc) are between 1380℃-1420℃

, and their metallographic structures are all austenite, and the austenite structure will definitely undergo plastic deformation when subjected to high temperature.

Therefore, the skid buttons in the heating furnace will also undergo plastic deformation under the gravity of the billet, and at the same time, the billet will have side bending, which will cause the local sik buttons or the local area of the skid buttons to  bear excessive pressure. The bearing strength exceeds its ultimate use strength at high temperature, and pits or edges are crushed on the surface of the skid buttons.

Our technical team increased the melting point of the alloy by about 40-50℃ with adding a large amount of W to the cobalt alloy, the performance has been greatly improved, and the effect is good. We named this material with HTN-W. This kind of skid buttons has been used in China's 2250mm hot rolling heating furnace for more than ten years, and it still can normal work.

For heating furnaces with high temperature requirements, such as silicon steel heating furnaces, the temperature in the furnace can reach up to 1420℃. In response to this feature, higher requirements have been placed on the heating furnace skid buttons. According to the characteristics of silicon steel furnace, the technical team has carried out the new research and development of high heat-resistant materials. Finally, a high-temperature metal glass material was selected with a melting point of 1750℃. It is well known that materials with galss sturcture have basically no plastic deformation before the melting point,d limit of oxidation resistance is 1500℃. The maximum pressure capacity is 4/5 times compared with Co alloy. It has been used in silicon steel heating furnaces for more than 8 years in 2009, and has achieved almost zero damage.

At present, our heating furnace skid buttons has multiple series of products to meet the needs of different heating funaces. Our conventional materials use high-quality raw materials to ensure a stable service life. The new material HTN-W, its service life far exceeds the traditional Co series materials, and can meet the needs of customers who have high requirements on the life of the skid buttons. Our metal glass material HTN-G can guarantee the silicon steel heating furnace to work for 8 years, the surface of skid buttons is almost zero damage. Please tell us your needs for skid butons, our engineers will provides the most professional solutions.