New Nano-Functional Ceramic Coating Technology for High Temperature Protection of Billets презентация

Contents
01 Oxidation burning loss of billet
02 High temperature protection technology
03 Technical effect
04 Economic benefit

01 Oxidation burning loss of billet

The Oxidation burning loss during billet (ingot) heating process

Adverse effects of high temperature oxidation
During the heating process of rolling steel, the oxidation burning loss accounts for about 1-1.5% of the weight of the blank. The forging heating burning loss will be higher, and the burning loss rate is as high as 3-5%.

Adverse effects of high temperature oxidation
When the furnace gas or furnace temperature is improperly controlled or the billet stays in the high temperature section for a long time, especially if the rolling failure occurs and the adjustment is not timely, the iron oxide scale of the steel will be thickened.
In general, the iron oxide scale thickness is 1-5mm, and in severe cases, it can reach 10mm.

Adverse effects of high temperature oxidation
If the iron oxide scale produced by high temperature oxidation is not cleaned up in time, it will be pressed into the surface of the billet during the rolling or forging process, resulting in surface defects of the product, causing the product to be scrapped.

Adverse effects of high temperature oxidation
When heating steel parts, high temperature oxidation will cause depletion and decarburization of alloying elements in the steel.

Adverse effects of high temperature oxidation
The changes in the chemical composition of the steel surface will cause a decline in the mechanical properties and corrosion resistance of the product, resulting in a reduction in the qualified rate of finished products.

Adverse effects of high temperature oxidation

02 High temperature protection technology

Solution - high temperature anti-oxidation nano-ceramic coating

03 Technical effect

Brief introduction of high temperature anti-oxidation nano-ceramic coating
The use of high temperature protective coating technology can reduce the primary oxidation burn loss by more than 90%, greatly improve the yield of steel in the production process, directly reduce the difficulty of removing iron oxide scale, alleviate the phenomenon of surface element depletion, and improve the yield and quality of steel.

Therefore, the research and application of multi-functional high-temperature protective coating technology has more important practical significance in the aspects of anti-oxidation, anti-decarburization, anti-element depletion and improvement of descaling level and rolled surface quality of high value-added steel grades.

Characteristics of high temperature anti-oxidation nano-ceramic coating
1. The coating can reduce the surface oxidation of the billet by more than 90%, greatly reducing the element depletion;

Characteristics of high temperature anti-oxidation nano-ceramic coating
2 Good chemical compatibility, mechanical compatibility, and CTE (coefficient of thermal expansion) matching between the coating and the substrate and between the inner layer of the coating and the layer;

Characteristics of high temperature anti-oxidation nano-ceramic coating
3. The coating is closely combined with the substrate during the transmission of the steel, and the mechanical action will not cause the coating to fall off at high temperature;

Characteristics of high temperature anti-oxidation nano-ceramic coating
4. The existing oxide layer on the surface of the coating and the steel substrate forms a new dense eutectic, which changes the structure of the oxide layer and improves the peeling performance of the oxide scale;

Characteristics of high temperature anti-oxidation nano-ceramic coating
5. The amount of coating is small, which does not affect the normal heating speed of the billet;

Characteristics of high temperature anti-oxidation nano-ceramic coating
6. The coating can automatically heal the cracks generated by itself in the high temperature process, ensuring the compactness and integrity of the coating;

Characteristics of high temperature anti-oxidation nano-ceramic coating
7. The coating itself has anti-oxidation performance and long protection life;

Characteristics of high temperature anti-oxidation nano-ceramic coating
8. The cost of coating is low. The existing anti-oxidation coatings for special steels are relatively expensive, while for ordinary low-carbon steels used in a large number of applications, these coatings are not practically applied, because of high cost.

Application effect of high temperature protective coating technology

Forging field application

Dephosphorization of nickel-containing steel hot rolled coils by protective coatings ---- Surface quality is improved

Mitigation effect of protective coating on decarburization depth of medium and high carbon steel grades

Mitigation effect of protective coating on decarburization depth of medium and high carbon steel grades

Mitigation effect of protective coating on the depth of decarburized layer of bearing steel

Practical significance of applying high temperature protective coating technology
Compared with the existing high-temperature protective coatings, the coating increases the protective temperature, effectively reduces the high-temperature oxidation burning loss, improves the peeling performance of the iron oxide scale after it is released from the furnace, saves energy to a large extent, and improves the yield and surface quality of the billet, from the perspective of energy saving, production and efficiency of steel rolling heat treatment production, it has produced obvious benefits.

Practical significance of applying high temperature protective coating technology
Most of the heating furnaces in the rolling and forging industries in the country are at a relatively low level in the world, which is why the oxidation burning loss and surface quality of the forging industry urgently need to be improved.

Practical significance of applying high temperature protective coating technology
The improvement of surface quality has played a significant role in improving the equipment life of downstream processes such as rolling process, pickling process and other supporting links, and reducing material consumption.

Practical significance of applying high temperature protective coating technology
The improvement of product quality also increases the added value of products and enhances the strategic competitiveness of enterprises themselves.

How to use high temperature protective coating

04 Economic benefit

Calculation of technical economic benefit of applied high temperature protective coating
5 million tons of ordinary carbon steel rolling mill as an example
1. Oxidation and burning condition:
The firing temperature is about 1200℃-1260℃, and the average oxidation burning loss rate of the billet is about 1.20%. The annual steel billet oxidation and burning loss is 60,000 tons, and the direct economic loss is: 60,000 tons × 3,800 / ton = 228 million RMB.

Calculation of technical economic benefit of applied high temperature protective coating
2. Saving benefits: After using our company's high-temperature anti-oxidation coating, the target is to reduce the oxidation burning loss rate by more than 80%, which can save the company 48,000 tons of steel billets every year, equivalent to 182 million RMB, and the coating consumption is about 0.8kg/ton, 4000t/year, The coating price is 15 RMB/kg, the coating cost is 60 million yuan, and the iron and steel enterprises can obtain direct economic benefits of 120 million RMB. At the same time, it brings the improvement of product surface quality, improves the product qualification rate, and the indirect benefits are also very considerable !
For special steel, alloying elements such as Si Ni Mn have complex reactions. Our company produces special coating materials for different steel grades.