阅读说明：本技术 一种耐热复合不锈钢及其热轧生产工艺 (Heat-resistant composite stainless steel and hot rolling production process thereof ) 是由 翟茂盛 张仕财 彭念学 李景 于 2019-10-11 设计创作，主要内容包括：本发明公开了一种耐热复合不锈钢及其热轧生产工艺,复合不锈钢成分重量百分比为：C≤0.02,Si≤0.038,Mn≤0.58,P≤0.018,S≤0.001,Cr≤19.45,Ni≤19.1,Mo≤0.91,Ti≤0.19,Al≤0.21,余量为Fe和不可避免的少量杂质；本发明采用燃气锻造炉进行加热,加热速度更快、生产效率更高、氧化脱炭少,同时节能减排减少环境污染；加热过程中不锈钢界面生成TiC层,连续均匀一定厚度的TiC层可以提升界面的结合强度；在不断加热过程中,TiC随温度升高而增多,断口的撕裂状形貌较为明显,有利于板坯获得较高的剪切强度。(The invention discloses a heat-resistant composite stainless steel and a hot rolling production process thereof, wherein the composite stainless steel comprises the following components in percentage by weight: c is less than or equal to 0.02, Si is less than or equal to 0.038, Mn is less than or equal to 0.58, P is less than or equal to 0.018, S is less than or equal to 0.001, Cr is less than or equal to 19.45, Ni is less than or equal to 19.1, Mo is less than or equal to 0.91, Ti is less than or equal to 0.19, Al is less than or equal to 0.21, and the balance of Fe and inevitable small impurities; the invention adopts the gas forging furnace for heating, has faster heating speed, higher production efficiency and less oxidation and decarburization, saves energy, reduces emission and reduces environmental pollution; a TiC layer is generated on a stainless steel interface in the heating process, and the TiC layer with a certain thickness is continuously and uniformly distributed, so that the bonding strength of the interface can be improved; in the continuous heating process, TiC increases along with the temperature rise, the tearing-shaped appearance of the fracture is obvious, and the plate blank is favorable for obtaining high shearing strength.)

1. A heat-resistant composite stainless steel and a hot rolling production process thereof are characterized in that the composite stainless steel comprises the following components in percentage by weight: c is less than or equal to 0.02, Si is less than or equal to 0.038, Mn is less than or equal to 0.58, P is less than or equal to 0.018, S is less than or equal to 0.001, Cr is less than or equal to 19.45, Ni is less than or equal to 19.1, Mo is less than or equal to 0.91, Ti is less than or equal to 0.19, Al is less than or equal to 0.21, and the balance of Fe and inevitable small impurities;

the process comprises the following steps:

1) heating: taking the raw materials of the components to enter a heating furnace for heating in a preheating section, adjusting the preheating temperature to 727-750 ℃, and heating for 59-80 minutes;

2) after the preheating is finished, entering a heating section, wherein the heating temperature is 1078 and 1050 ℃, and the heating time is 92-110 minutes;

3) entering a heating second stage after the heating first stage is finished, wherein the temperature of the heating second stage is 1232-;

4) after the heating second section is finished, entering a heating equalizing section, wherein the temperature of the heating equalizing section is 1241-;

5) rough rolling: roughly rolling the heated plate blank, closing high-pressure dephosphorization water, and controlling the temperature of a rough rolling outlet at 1119-;

6) finish rolling: performing finish rolling by adopting 6-8 finish rolling mills, wherein the tension between the stands is 3-15MPa, the finish rolling inlet temperature is controlled between 1025 and 1060 ℃, and the finish rolling temperature is controlled between 990 and 1020 ℃;

7) coiling: the coiling temperature is 730 ℃ and 750 ℃, and the coiling tension is 3-15 tons.

2. The heat-resistant composite stainless steel and hot rolling process according to claim 1, wherein the heating is performed in a gas forging furnace.

3. The heat-resistant composite stainless steel and hot rolling process according to claim 1, wherein the total heating time of the slab is reasonably controlled to 245 ± 20 minutes.

4. A heat-resistant composite stainless steel and a hot rolling production process thereof are characterized in that the composite stainless steel comprises the following components in percentage by weight: c is less than or equal to 0.02, Si is less than or equal to 0.2, Mn is less than or equal to 0.83, P is less than or equal to 0.017, S is less than or equal to 0.001, Cr is less than or equal to 20.75, Ni is less than or equal to 31.36, Cu is less than or equal to 0.04, Ti is less than or equal to 0.31, Al is less than or equal to 0.23, and the balance of Fe and inevitable small impurities;

the process comprises the following steps:

1) heating: taking the raw materials of the components to carry out preheating section heating, adjusting the preheating temperature to 670-;

2) after the preheating is finished, entering a heating section, wherein the heating temperature is 1105-1150 ℃, and the heating time is 92-110 minutes;

3) entering a heating second stage after the heating first stage is finished, wherein the temperature of the heating second stage is 1234-1400 ℃, and the heating time lasts for 57-72 minutes;

4) entering a heating equalizing section after the heating second section is finished, wherein the temperature of the heating equalizing section is 1242-1255 ℃, and the heating time lasts for 37-45 minutes;

5) rough rolling: roughly rolling the heated plate blank, closing high-pressure dephosphorization water, and controlling the temperature of a rough rolling outlet at 1117-;

6) finish rolling: carrying out finish rolling by adopting 5-7 finish rolling mills, wherein the tension between the stands is 3-15MPa, the inlet temperature of the finish rolling is controlled between 1050-1025 ℃ and the finish rolling temperature is controlled between 980-1025 ℃;

7) coiling: the coiling temperature is 730 ℃ and 750 ℃, and the coiling tension is 5 to 18 tons.

5. The heat-resistant composite stainless steel and hot rolling process according to claim 1, wherein the heating is performed in a gas forging furnace.

6. The heat-resistant composite stainless steel and hot rolling process according to claim 1, wherein the total heating time of the slab is reasonably controlled to 245 ± 20 minutes.

Technical Field

The invention belongs to the technical field of stainless steel production, and particularly relates to heat-resistant composite stainless steel and a hot rolling production process thereof.

Background

The composite stainless steel is a low-consumption, high-efficiency, energy-saving and environment-friendly product, has the characteristics of stainless steel and common steel, has very high strength, good toughness and ductility, good absorption capacity for collision and excellent corrosion resistance, and can form a thin and compact protective chromium oxide passivation film on the surface when exposed in water or air.

The following problems often exist in the existing composite stainless steel production technology: 1) in the heating process, the heat conduction efficiency is not high, the energy consumption is increased, the environmental protection is not facilitated, and meanwhile, the situation that the heating time is too long when the temperature does not reach can occur; 2) The production mode of compounding multiple elements is easy to cause the phenomenon of falling off because the bonding strength of each interface cannot be achieved.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the heat-resistant composite stainless steel and the hot rolling production process thereof, a gas forging furnace is adopted for heating, the heating speed is higher, the production efficiency is higher, the oxidation and decarburization are less, and meanwhile, the energy is saved, the emission is reduced, and the environmental pollution is reduced; a TiC layer is generated on a stainless steel interface in the heating process, and the TiC layer with a certain thickness is continuously and uniformly distributed, so that the bonding strength of the interface can be improved; in the continuous heating process, TiC increases along with the temperature rise, the tearing-shaped appearance of the fracture is obvious, and the plate blank is favorable for obtaining high shearing strength.

In order to achieve the purpose, the invention adopts the technical scheme that:

a heat-resistant composite stainless steel and a hot rolling production process thereof comprise the following components in percentage by weight: c is less than or equal to 0.02, Si is less than or equal to 0.038, Mn is less than or equal to 0.58, P is less than or equal to 0.018, S is less than or equal to 0.001, Cr is less than or equal to 19.45, Ni is less than or equal to 19.1, Mo is less than or equal to 0.91, Ti is less than or equal to 0.19, Al is less than or equal to 0.21, and the balance of Fe and inevitable small impurities;

the process comprises the following steps:

1) heating: taking the raw materials of the components to enter a heating furnace for heating in a preheating section, adjusting the preheating temperature to 727-750 ℃, and heating for 59-80 minutes;

2) after the preheating is finished, entering a heating section, wherein the heating temperature is 1078-;

3) entering a heating second stage after the heating first stage is finished, wherein the temperature of the heating second stage is 1232-;

4) after the heating second section is finished, entering a heating equalizing section, wherein the temperature of the heating equalizing section is 1241-;

5) rough rolling: roughly rolling the heated plate blank, closing high-pressure dephosphorization water, and controlling the temperature of a rough rolling outlet at 1119-;

6) finish rolling: performing finish rolling by adopting 6-8 finish rolling mills, wherein the tension between the stands is 3-15MPa, the finish rolling inlet temperature is controlled between 1025 and 1060 ℃, and the finish rolling temperature is controlled between 990 and 1020 ℃;

7) coiling: the coiling temperature is 730 ℃ and 750 ℃, and the coiling tension is 3-15 tons.

Preferably, the heating is performed by adopting a gas forging furnace, and the gas forging furnace is an improved furnace type which is provided with gas generated by a gas generating furnace for combustion heating on the basis of an original coal-fired heating furnace.

Preferably, the total heating time of the plate blank is reasonably controlled to be 245 +/-20 minutes, so that the situation that the time is insufficient, the strength of the plate blank cannot be achieved, and the situation that the whole quality of the plate blank is influenced due to too long time is prevented.

Further, the heat-resistant composite stainless steel and the hot rolling production process thereof comprise the following components in percentage by weight: c is less than or equal to 0.02, Si is less than or equal to 0.2, Mn is less than or equal to 0.83, P is less than or equal to 0.017, S is less than or equal to 0.001, Cr is less than or equal to 20.75, Ni is less than or equal to 31.36, Cu is less than or equal to 0.04, Ti is less than or equal to 0.31, Al is less than or equal to 0.23, and the balance of Fe and inevitable small impurities;

the process comprises the following steps:

1) heating: taking the raw materials of the components to carry out preheating section heating, adjusting the preheating temperature to 670-;

2) after the preheating is finished, entering a heating section, wherein the heating temperature is 1105-1150 ℃, and the heating time is 92-110 minutes, and the TiC layer with a certain thickness and continuous uniformity generated on the stainless steel interface can improve the bonding strength of the interface;

3) entering a heating second stage after the heating first stage is finished, wherein the temperature of the heating second stage is 1234-1400 ℃, and the heating time lasts for 57-72 minutes;

4) entering a heating equalizing section after the heating second section is finished, wherein the temperature of the heating equalizing section is 1242-1255 ℃, and the heating time lasts for 37-45 minutes;

5) rough rolling: roughly rolling the heated plate blank, closing high-pressure dephosphorization water, and controlling the temperature of a rough rolling outlet at 1117-;

6) finish rolling: carrying out finish rolling by adopting 5-7 finish rolling mills, wherein the tension between the stands is 3-15MPa, the inlet temperature of the finish rolling is controlled between 1050-1025 ℃ and the finish rolling temperature is controlled between 980-1025 ℃;

7) coiling: the coiling temperature is 730 ℃ and 750 ℃, and the coiling tension is 5 to 18 tons.

Preferably, the heating is performed by adopting a gas forging furnace, and the gas forging furnace is an improved furnace type which is provided with gas generated by a gas generating furnace for combustion heating on the basis of an original coal-fired heating furnace.

Preferably, the total heating time of the plate blank is reasonably controlled to be 245 +/-20 minutes, so that the situation that the time is insufficient, the strength of the plate blank cannot be achieved, and the situation that the whole quality of the plate blank is influenced due to too long time is prevented.

Compared with the prior art, the invention has the beneficial effects that:

1) compared with the combustion chamber of the original coal-fired heating furnace, the gas forging furnace is more direct, the gas produced by the gas generating furnace is sprayed and combusted into the heating chamber by using the gas burner, the heating speed is higher, the production efficiency is higher, the oxidation and decarburization are less, and meanwhile, the energy is saved, the emission is reduced, and the environmental pollution is reduced.

2) After the heating is finished for a period of time, the TiC layer generated on the stainless steel interface can effectively reduce the generation of interface brittle metal compounds and Ti-Fe brittle compounds, so that the TiC layer with a certain continuous and uniform thickness can improve the bonding strength of the interface.

3) When the composite plate is heated for the second period, TiC is increased along with the temperature rise, metal oxides on a temperature rise interface are increased simultaneously, a fracture layer of the composite plate is in brittle fracture, the tearing shape of the fracture is obvious, and the plate blank of the composite plate obtains high shearing strength.

The attached table 1 shows the performance test results of the composite stainless steel slab of the invention and different embodiments of the hot rolling production process;

Detailed Description

For the convenience of understanding of those skilled in the art, the following will be made to further specify the results and properties of the technical solutions of the present invention in conjunction with the attached table 1.