Cold rolling machining process for X32 high-alloy saw blade steel

Abstract

The invention relates to a cold rolling machining process for X32 high-alloy saw blade steel. The cold rolling machining process comprises the following steps that a hot-rolled acid-pickled steel coil with the mark of X32 is selected; softening and annealing the hot-rolled and pickled steel coil to obtain a softened and annealed steel coil; the softened and annealed steel coil is roughly and longitudinally sheared into strips, and a longitudinally-sheared narrow strip steel coil is prepared; primary spheroidizing annealing is conducted on the longitudinally-sheared narrow strip steel coil, and a primary spheroidizing annealing steel coil is obtained; carrying out primary rough rolling on the primary spheroidizing annealing steel coil to obtain a primary rolled steel coil; carrying out secondary spheroidizing annealing on the primary rolled steel coil to obtain a secondary spheroidizing annealed steel coil; carrying out secondary rough rolling on the secondary spheroidizing annealed steel coil; performing finish rolling to obtain a finish rolled steel coil; longitudinally shearing and slitting; and the split cold-rolled steel coils are packaged. A hot-rolled and pickled steel coil raw material is directly adopted for large coil softening annealing, and the problems that after hot-rolled coils are subjected to finish rolling, the cooling speed of the head and the tail is uneven, the strength is high, edge notches are affected by shearing stress during longitudinal shearing and splitting, and cracks are generated on the edges in the rolling and bending process are solved through annealing.

Description

Technical Field

[0001] The invention relates to the technical field of strip steel production and processing, and in particular to a cold rolling processing technology of X32 high-alloy saw blade steel. Background Art

[0002] X32 spheroidized cold-rolled steel coil is a high-alloy high-performance saw blade steel. Three years ago, this material was completely imported. Its procurement cycle is long. With customers' increasingly high quality and personalized needs, the cold rolling process must be updated and optimized in line with market demand changes. This requires a faster response speed to optimize the process and obtain high-quality cold-rolled products that meet market requirements.

[0003] Affected by various objective factors such as the relatively backward processing technology of cold-rolled strip steel in China, the manufacturing process of X32 spheroidized cold-rolled steel coil has relatively high technical requirements. For example, its raw materials have high alloy content, the tensile strength of hot-rolled coil can reach nearly 2000MPa, and the hardness can reach 50HRC. Therefore, the matching of cold rolling process is extremely important. The rolling reduction ratio does not match the annealing process, making it difficult to obtain excellent equiaxed grains and spheroidized pearlite structure and mechanical properties during steel annealing. It is easy to form rolling microcracks, which will lead to fracture, and the entire production yield is low. Summary of the invention

[0004] The technical problem to be solved by the present invention is to study a cold rolling processing technology of X32 high alloy saw blade steel, which can improve production efficiency and stabilize product quality.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] A cold rolling process for X32 high alloy saw blade steel comprises the following steps:

[0007] Step 01, select a hot-rolled pickled steel coil with a grade of X32;

[0008] Step 02, performing soft annealing on the hot-rolled pickled steel coil to obtain a soft annealed steel coil;

[0009] Step 03, roughly slitting the softened annealed steel coil into strips to obtain slitting narrow strip steel coils;

[0010] Step 04, performing primary spheroidizing annealing on the slit narrow strip steel coil to obtain a primary spheroidizing annealed steel coil;

[0011] Step 05, rough rolling the primary spheroidizing annealing steel coil once to obtain a primary rolled steel coil;

[0012] Step 06, performing secondary spheroidizing annealing on the primary rolled steel coil to obtain a secondary spheroidizing annealed steel coil;

[0013] Step 07, performing secondary rough rolling on the secondary spheroidizing annealing steel coil to obtain a secondary rolled steel coil;

[0014] Step 08, finishing rolling the secondary rolled steel coil to obtain a finished rolled steel coil;

[0015] Step 09, slitting the finished rolled steel coil into strips to obtain stripped cold rolled steel coils;

[0016] Step 10: Pack and package the slit cold-rolled steel coils.

[0017] The beneficial effects of the present invention are: directly using hot-rolled pickled steel coil raw materials for large coil softening annealing, improving the uneven cooling rate and high strength of the head and tail of the hot-rolled coil after final rolling through annealing, and the edge cuts are affected by shear stress during longitudinal shearing and stripping, and cracks are generated on the edges during the coiling and bending process. In addition, because the pickled steel coil has effectively removed the surface iron oxide scale and the oxygen molecules on the surface of the matrix before annealing, it loses the opportunity to combine with oxygen molecules during full hydrogen furnace annealing, which significantly improves the decarburization tendency during subsequent annealing; and through subsequent secondary spheroidizing annealing (sub-temperature spheroidizing), the structure and hardness of the head and middle coil of the steel coil are close, so that the stress distribution inside the steel coil during rolling is relatively uniform, so as to obtain a good rolled plate shape. Thereby, the quality of the products produced is more stable and the production efficiency is significantly improved.

[0018] Based on the above technical solution, the present invention can also be improved as follows.

[0019] Furthermore, softening annealing, primary spheroidizing annealing and secondary spheroidizing annealing are all carried out in a bell-type annealing furnace; and the steel coils are transported by a overhead crane.

[0020] Further, step 02 specifically includes: the hot-rolled pickled steel coil is transferred to a hood annealing furnace by a crane device for softening annealing: first, during softening annealing, the hood annealing furnace is heated to 200°C at full speed; the temperature is set to 4h to be heated to 420°C; the temperature is set to 6h to be heated to 705°C and kept warm for 2 hours; the temperature is set to 1h to be heated to 725°C and kept warm for 12 hours; after the insulation is completed, the furnace is cooled to 650°C, and after the furnace is cooled to 650°C, the hood is replaced with air cooling, and the temperature of the hood annealing furnace is reduced to 320°C. After the temperature of the hood annealing furnace is reduced to 320°C, the temperature of the hood annealing furnace is reduced from 320°C to 120°C by water cooling on the inner hood, and the hood is taken out of the furnace to obtain a softened annealed steel coil.

[0021] Further, step 03 specifically includes: hoisting the softened annealed steel coil to a slitting machine for rough slitting to obtain slitting narrow strip steel coils.

[0022] Further, step 04 specifically includes: transferring the slit narrow strip steel coil to the bell-type annealing furnace through the overhead crane device for primary spheroidizing annealing: first, heating the bell-type annealing furnace to 200°C at full speed; setting the time to heat up to 420°C for 5 hours; setting the time to heat up to 755°C for 8 hours and keep it at this temperature for 4 hours, cooling it with the furnace to 725°C and keeping it at this temperature for 2 hours; heating it at full speed to 755°C and keeping it at this temperature for 4 hours, continuing to cool it with the furnace to 725°C and keeping it at this temperature for 2 hours; heating it at full speed to 755°C and keeping it at this temperature for 4 hours, continuing to cool it with the furnace to 725°C and keeping it at this temperature for 2 hours; heating it at full speed to 755°C and keeping it at this temperature for Keep warm for 4 hours, continue to cool with the furnace to 725℃ and keep warm for 2h; heat up to 755℃ at full speed again and keep warm for 4 hours; cool with the furnace to 650℃ after the insulation is completed, and after cooling to 650℃, replace the hood of the annealing furnace with air cooling, and reduce the temperature of the annealing furnace to 320℃. After the temperature of the annealing furnace is reduced to 320℃, the inner hood is cooled by water spraying to reduce the temperature of the annealing furnace from 320℃ to 80℃, and the primary spheroidizing annealing steel coil is obtained.

[0023] Further, step 05 specifically includes: transferring the primary spheroidizing annealing steel coil to the AGC reversible rolling mill production line through a crane device for repeated rolling to obtain the primary rolled steel coil.

[0024] Further, step 06 specifically includes: transferring the primary rolled steel coil to a bell-type annealing furnace for a second spheroidizing annealing by means of a crane; first, heating the bell-type annealing furnace to 200°C at full speed; setting the time to heat up to 420°C for 5 hours; setting the time to heat up to 740°C for 7 hours and keep it at that temperature for 4 hours, cooling it with the furnace to 710°C and keeping it at that temperature for 2 hours; heating it at full speed to 740°C and keeping it at that temperature for 4 hours, continuing to cool it with the furnace to 710°C and keeping it at that temperature for 2 hours; heating it at full speed to 740°C and keeping it at that temperature for 4 hours, continuing to cool it with the furnace to 710°C and keeping it at that temperature for 2 hours; heating it at full speed to 740°C and keeping it at that temperature for Keep warm for 4 hours, continue to cool with the furnace to 710℃ and keep warm for 2h; heat up to 740℃ at full speed again and keep warm for 4 hours; cool with the furnace to 650℃ after the insulation; after cooling with the furnace to 650℃, replace the hood and air cool the hood, and reduce the temperature of the hood annealing furnace to 320℃. After the temperature of the hood annealing furnace drops to 320℃, use the method of water cooling on the inner hood to reduce the temperature of the hood annealing furnace from 320℃ to 80℃ and take it out of the furnace to obtain the secondary spheroidizing annealing steel coil.

[0025] Further, step 07 specifically includes: transferring the secondary spheroidizing annealing steel coil to the AGC reversible rolling mill production line through a crane device for repeated rolling to obtain a secondary rolled steel coil.

[0026] Further, step 08 specifically includes: transferring the secondary rolled steel coil to a finishing mill for finishing rolling to obtain a finished rolled steel coil.

[0027] Further, step 09 specifically includes: subjecting the finished rolled steel coil to fine longitudinal shearing and slitting through a small longitudinal shearing and slitting machine to obtain slit cold rolled steel coils.

[0028] Furthermore, step 10 specifically includes: using a baler to pack the stripped cold-rolled steel coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a cold rolling process flow chart of an X32 high alloy saw blade steel according to the present invention;

[0030] Figure 2 It is a time-temperature line graph of the softening annealing of the present invention;

[0031] Figure 3 It is the time-temperature line graph of the primary spheroidizing annealing of the present invention;

[0032] Figure 4 It is a time-temperature line graph of the secondary spheroidizing annealing of the present invention. DETAILED DESCRIPTION

[0033] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0034] like Figures 1 to 4 As shown, in Example 1 of the present invention, a cold rolling process of X32 high alloy saw blade steel comprises step 01, selecting a hot rolled pickled steel coil with a grade of X32;

[0035] Step 02, performing soft annealing on the hot-rolled pickled steel coil to obtain a soft annealed steel coil;

[0036] Step 03, roughly slitting the softened annealed steel coil into strips to obtain slitting narrow strip steel coils;

[0037] Step 04, performing primary spheroidizing annealing on the slit narrow strip steel coil to obtain a primary spheroidizing annealed steel coil;

[0038] Step 05, rough rolling the primary spheroidizing annealing steel coil once to obtain a primary rolled steel coil;

[0039] Step 06, performing secondary spheroidizing annealing on the primary rolled steel coil to obtain a secondary spheroidizing annealed steel coil;

[0040] Step 07, performing secondary rough rolling on the secondary spheroidizing annealing steel coil to obtain a secondary rolled steel coil;

[0041] Step 08, finishing rolling the secondary rolled steel coil to obtain a finished rolled steel coil;

[0042] Step 09, slitting the finished rolled steel coil into strips to obtain stripped cold rolled steel coils;

[0043] Step 10: Pack and package the slit cold-rolled steel coils.

[0044] Hot-rolled pickled steel coils are directly used as raw materials for large coil softening annealing. Annealing is used to improve the uneven cooling rate and high strength of the head and tail of the hot-rolled coil after final rolling. The edge cut is affected by shear stress during longitudinal shearing and striping, and cracks occur on the edge during the winding and bending process. In addition, the pickled steel coils have effectively removed the surface iron oxide scale and oxygen molecules on the surface of the matrix before annealing, so that they lose the opportunity to combine with oxygen molecules during full hydrogen furnace annealing, which significantly improves the decarburization tendency during subsequent annealing; and through subsequent secondary spheroidizing annealing (sub-temperature spheroidizing), the structure and hardness of the head and middle coils of the steel coils are close, so that the stress distribution in the steel coils during rolling is relatively uniform, so as to obtain a good rolled plate shape. In this way, the quality of the products produced is more stable and the production efficiency is significantly improved.

[0045] Embodiment 2 of the present invention is a cold rolling processing technology for X32 high alloy saw blade steel. On the basis of Embodiment 1, softening annealing, primary spheroidizing annealing and secondary spheroidizing annealing are all carried out in a hood annealing furnace; the steel coil is transported by a overhead crane.

[0046] Embodiment 3 of the present invention is a cold rolling processing technology for X32 high alloy saw blade steel. On the basis of embodiment 1 or 2, step 02 specifically includes: the hot-rolled pickled steel coil is transferred to a hood annealing furnace by a overhead crane for softening annealing: first, during softening annealing, the hood annealing furnace is heated to 200°C at full speed; set time 4h to heat to 420°C; set time 6h to heat to 705°C and keep warm for 2 hours; set time 1h to heat to 725°C and keep warm for 12 hours; after the insulation is completed, the furnace is cooled to 650°C, and after cooling to 650°C, the hood annealing furnace is replaced with a hood and air-cooled, and the temperature of the hood annealing furnace is reduced to 320°C. After the temperature of the hood annealing furnace is reduced to 320°C, the temperature of the hood annealing furnace is reduced from 320°C to 120°C by water cooling on the inner hood, so as to obtain a softened annealed steel coil.

[0047] Embodiment 4 of the present invention is a cold rolling processing technology of X32 high alloy saw blade steel. On the basis of embodiment 2, step 04 specifically includes: transferring the slit narrow strip steel coil to a bell-type annealing furnace through a crane device for primary spheroidizing annealing: first, the bell-type annealing furnace is heated to 200°C at full speed; the temperature is set to 420°C for 5 hours; the temperature is set to 755°C for 8 hours and kept at this temperature for 4 hours, and then cooled to 725°C and kept at this temperature for 2 hours; the temperature is raised to 755°C at full speed and kept at this temperature for 4 hours, and then cooled to 725°C with the furnace; the temperature is raised to 755°C at full speed and kept at this temperature for 4 hours, and then cooled to 725°C with the furnace. and keep it warm for 2h; heat up to 755℃ at full speed and keep it warm for 4h, continue to cool with the furnace to 725℃ and keep it warm for 2h; heat up to 755℃ at full speed again and keep it warm for 4h; cool with the furnace to 650℃ after the insulation, after cooling to 650℃, replace the hood of the annealing furnace with air cooling, and reduce the temperature of the annealing furnace to 320℃. After the temperature of the annealing furnace is reduced to 320℃, the inner hood is cooled by water spraying to reduce the temperature of the annealing furnace from 320℃ to 80℃, and the primary spheroidizing annealing steel coil is obtained. In the specific implementation, the annealing furnace is heated to 200℃ at full speed; set the time to heat to 420℃ for 4h; set the time to heat to 705℃ for 6h and keep it warm for 2 hours; set the time to heat to 725℃ for 1h and keep it warm for 10 hours; after the insulation is completed, the furnace is cooled to 650℃, and the annealing furnace is cooled to 650℃, and the annealing furnace is replaced with a cover and air-cooled, and the temperature of the annealing furnace is reduced to 320℃. After the temperature of the annealing furnace is reduced to 320℃, the inner cover is cooled by water spraying to reduce the temperature of the annealing furnace from 320℃ to 120℃ before it is taken out of the furnace. The high-temperature insulation time is shortened (from 12h to 10h), and the quality of the edges of the longitudinal shear strips can still be effectively ensured, which can save 2h of annealing time and slightly improve production efficiency.

[0048] Embodiment 5 of the present invention is a cold rolling process for X32 high alloy saw blade steel. Based on Embodiment 2, step 05 specifically includes: transferring the primary spheroidizing annealing steel coil to the AGC reversible rolling mill production line through a crane device for repeated rolling to obtain the primary rolled steel coil. In specific implementation, the thickness of the primary spheroidizing annealing steel coil in step 04 is rolled from 3.0 mm to 1.9 mm.

[0049] Embodiment 6 of the present invention is a cold rolling process for X32 high alloy saw blade steel. Based on Embodiment 2, step 06 specifically includes: transferring the primary rolled steel coil to a bell-type annealing furnace for a second spheroidizing annealing through a crane device; first, heating the bell-type annealing furnace to 200°C at full speed; setting the temperature to 420°C for 5 hours; setting the temperature to 740°C for 7 hours and keeping it warm for 4 hours, cooling it to 710°C with the furnace and keeping it warm for 2 hours; heating it to 740°C at full speed and keeping it warm for 4 hours, and continuing to cool it to 710°C with the furnace and keep it warm for 2h; heat up to 740℃ at full speed and keep it warm for 4h, continue to cool with the furnace to 710℃ and keep it warm for 2h; heat up to 740℃ at full speed again and keep it warm for 4h; cool with the furnace to 650℃ after the insulation; after cooling with the furnace to 650℃, replace the hood and air cool the hood annealing furnace, and reduce the temperature of the hood annealing furnace to 320℃. After the temperature of the hood annealing furnace is reduced to 320℃, the inner hood is cooled by water spraying to reduce the temperature of the hood annealing furnace from 320℃ to 80℃, and the secondary spheroidizing annealing steel coil is obtained. During the specific implementation, the annealing furnace is heated to 200°C at full speed; the temperature is set to 420°C in 5 hours; the temperature is set to 700°C in 5 hours and kept warm for 2 hours; the temperature is set to 740°C in 1 hour and kept warm for 4 hours, cooled to 710°C and kept warm for 2 hours; the temperature is raised to 740°C at full speed and kept warm for 4 hours, continued to cool to 710°C and kept warm for 2 hours; the temperature is raised to 740°C at full speed and kept warm for 4 hours, continued to cool to 710°C and kept warm for 2 hours; the temperature is raised to 740°C at full speed and kept warm for 4 hours, continued to cool to 710°C and kept warm for 2 hours; the temperature is raised to 740°C at full speed and kept warm for 4 hours, continued to cool to 710°C and kept warm for 2 hours; the temperature is raised to 740°C at full speed again and kept warm for 4 hours; after the insulation is completed, the furnace is cooled to 650°C, and after the furnace is cooled to 650°C, the annealing furnace is replaced with a cover for air cooling, and the temperature of the annealing furnace is reduced to 320°C. After the temperature of the annealing furnace is reduced to 320°C, the temperature of the annealing furnace is reduced from 320°C to 80°C by spraying water on the inner cover for cooling. In the second spheroidizing annealing, a 700℃ insulation buffer platform is added before preparing to raise the maximum temperature to 740℃. This can reduce the "oscillation curve" effect caused by the lack of a buffer step when the temperature rises directly from low temperature, reduce overheating, and easily grasp the accuracy of high-temperature insulation time; reduce the performance and hardness differences at the head, middle and tail of the spheroidizing annealing coil, and further improve the stability of the overall quality.

[0050] Embodiment 7 of the present invention is a cold rolling process for X32 high alloy saw blade steel. Based on Embodiment 2, step 07 specifically includes: transferring the secondary spheroidizing annealing steel coil to the AGC reversible rolling mill production line through a crane device for repeated rolling to obtain a secondary rolled steel coil. In specific implementation, the thickness of the secondary spheroidizing annealing steel coil in step 05 is rolled from 1.9 mm to 1.36 mm.

[0051] Embodiment 8 of the present invention is a cold rolling process for X32 high alloy saw blade steel. Based on Embodiment 2, step 08 specifically includes: transferring the secondary rolled steel coil to a finishing mill for finishing rolling to obtain a finished rolled steel coil. Finishing rolling improves the surface finish quality while obtaining a precision finished product thickness with a smaller difference. In specific implementation, the thickness of the secondary rolled steel coil in step 07 is rolled from 1.36 mm to 1.33 mm.

[0052] Embodiment 9 of the present invention is a cold rolling process for X32 high alloy saw blade steel. Based on Embodiment 2, step 09 specifically includes: fine longitudinal shearing and slitting the finished rolled steel coil through a small longitudinal shearing and slitting machine to obtain slit cold rolled steel coil. In specific implementation, step 041.33*335mm is finely longitudinally sheared into 8 rolls of 1.33*40.1*C steel coil; before fine longitudinal shearing and slitting, the head and tail of the finished rolled steel coil must be inspected using a metallographic microscope and a hardness tester, and the hardness value, metallographic structure spheroidization rate, and decarburization layer depth of the finished rolled steel coil must be pre-inspected to ensure that the finished rolled steel coil with qualified indicators flows into the small longitudinal shearing and slitting machine, and the parameter values ​​in the production process can be adjusted in time according to the detection data, and it is pre-determined whether to transfer production to ensure the quality of finished product production.

[0053] Embodiment 10 of the present invention is a cold rolling process for X32 high alloy saw blade steel. Based on Embodiment 2, step 10 specifically includes: using a baler to pack the stripped cold rolled steel coils. Specific embodiments

[0055]

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A cold rolling process for X32 high alloy saw blade steel, characterized in that: The steps include: Step 01, select a hot-rolled pickled steel coil with a grade of X32; Step 02, performing soft annealing on the hot-rolled pickled steel coil to obtain a soft annealed steel coil; Step 03, roughly slitting the softened annealed steel coil into strips to obtain slitting narrow strip steel coils; Step 04, performing primary spheroidizing annealing on the slit narrow strip steel coil to obtain a primary spheroidizing annealed steel coil; Step 05, rough rolling the primary spheroidizing annealing steel coil once to obtain a primary rolled steel coil; Step 06, performing secondary spheroidizing annealing on the primary rolled steel coil to obtain a secondary spheroidizing annealed steel coil; Step 07, performing secondary rough rolling on the secondary spheroidizing annealing steel coil to obtain a secondary rolled steel coil; Step 08, finishing rolling the secondary rolled steel coil to obtain a finished rolled steel coil; Step 09, slitting the finished rolled steel coil into strips to obtain stripped cold rolled steel coils; Step 10: Pack and package the slit cold-rolled steel coils.

2. According to claim 1, a cold rolling process of X32 high alloy saw blade steel is characterized in that: The softening annealing, the primary spheroidizing annealing and the secondary spheroidizing annealing are all carried out in a bell-type annealing furnace; the steel coils are transported by a crane.

3. According to claim 1, a cold rolling process of X32 high alloy saw blade steel is characterized in that: The step 02 specifically includes: the hot-rolled pickled steel coil is transferred to a hood annealing furnace through a crane device for softening annealing: first, during softening annealing, the hood annealing furnace is heated to 200°C at full speed; the temperature is set to 4h to be heated to 420°C; the temperature is set to 6h to be heated to 705°C and kept warm for 2 hours; the temperature is set to 1h to be heated to 725°C and kept warm for 12 hours; after the insulation is completed, the furnace is cooled to 650°C, and after cooling to 650°C, the hood is replaced with air cooling for the hood annealing furnace, and the temperature of the hood annealing furnace is reduced to 320°C. After the temperature of the hood annealing furnace is reduced to 320°C, the temperature of the hood annealing furnace is reduced from 320°C to 120°C by cooling the inner hood with water, and the hood is taken out of the furnace to obtain a softened annealed steel coil.

4. According to claim 1, a cold rolling process of X32 high alloy saw blade steel is characterized in that: The step 03 specifically includes: hoisting the softened annealed steel coil to a slitting machine for rough slitting into strips to obtain slitting narrow strip steel coils.

5. According to claim 1, a cold rolling process of X32 high alloy saw blade steel is characterized in that: The step 04 specifically includes: transferring the slit narrow strip steel coil to the bell-type annealing furnace through the overhead crane device for primary spheroidizing annealing: first, heating the bell-type annealing furnace to 200°C at full speed; setting the time to heat up to 420°C in 5 hours; setting the time to heat up to 755°C in 8 hours and keep it at this temperature for 4 hours, cooling it to 725°C with the furnace and keeping it at this temperature for 2 hours; heating it to 755°C at full speed and keeping it at this temperature for 4 hours, continuing to cool it to 725°C with the furnace and keeping it at this temperature for 2 hours; heating it to 755°C at full speed and keeping it at this temperature for 4 hours, continuing to cool it to 725°C with the furnace and keeping it at this temperature for 2 hours; heating it to 755°C at full speed and keeping it at this temperature for The hood annealing furnace is heated for 4 hours, and then cooled to 725℃ and kept at this temperature for 2 hours; the temperature is raised to 755℃ at full speed again and kept at this temperature for 4 hours; after the insulation is completed, the hood is cooled to 650℃ with the furnace, and after cooling to 650℃, the hood of the hood annealing furnace is replaced with air cooling, and the temperature of the hood annealing furnace is reduced to 320℃. After the temperature of the hood annealing furnace is reduced to 320℃, the temperature of the hood annealing furnace is reduced from 320℃ to 80℃ by cooling the inner hood with water, and the steel coil is taken out of the furnace to obtain the primary spheroidizing annealing steel coil.

6. According to claim 1, a cold rolling process of X32 high alloy saw blade steel is characterized in that: The step 05 specifically includes: transferring the primary spheroidizing annealing steel coil to the AGC reversible rolling mill production line through a crane device for repeated rolling to obtain the primary rolled steel coil.

7. The cold rolling process of X32 high alloy saw blade steel according to claim 1, characterized in that: The step 06 specifically includes: transferring the primary rolled steel coil to a bell-type annealing furnace for a second spheroidizing annealing by means of a crane; first, heating the bell-type annealing furnace to 200°C at full speed; setting the time to heat up to 420°C in 5 hours; setting the time to heat up to 740°C in 7 hours and keep it at that temperature for 4 hours, cooling it with the furnace to 710°C and keeping it at that temperature for 2 hours; heating it to 740°C at full speed and keeping it at that temperature for 4 hours, continuing to cool it with the furnace to 710°C and keeping it at that temperature for 2 hours; heating it to 740°C at full speed and keeping it at that temperature for 4 hours, continuing to cool it with the furnace to 710°C and keeping it at that temperature for 2 hours; heating it to 740°C at full speed and keeping it at that temperature for The annealing furnace is heated for 4 hours, and then cooled to 710℃ and kept at this temperature for 2 hours; the temperature is raised to 740℃ at full speed again and kept at this temperature for 4 hours; after the heat preservation, the annealing furnace is cooled to 650℃; after the annealing furnace is cooled to 650℃, the hood is replaced with air cooling, and the temperature of the annealing furnace is reduced to 320℃. After the temperature of the annealing furnace is reduced to 320℃, the inner hood is cooled by water spraying to reduce the temperature of the annealing furnace from 320℃ to 80℃, and the steel coil is taken out of the furnace to obtain the secondary spheroidizing annealing steel coil.

8. The cold rolling process of X32 high alloy saw blade steel according to claim 1, characterized in that: The step 07 specifically includes: transferring the secondary spheroidizing annealing steel coil to the AGC reversible rolling mill production line through a crane device for repeated rolling to obtain a secondary rolled steel coil.

9. The cold rolling process of X32 high alloy saw blade steel according to claim 1, characterized in that: The step 08 specifically includes: transferring the secondary rolled steel coil to a finishing mill for finishing rolling to obtain a finished rolled steel coil.

10. The cold rolling process of X32 high alloy saw blade steel according to claim 1, characterized in that: The step 09 specifically includes: subjecting the finished rolled steel coil to fine longitudinal shearing and slitting through a small longitudinal shearing and slitting machine to obtain slit cold rolled steel coils.

11. The cold rolling process of X32 high alloy saw blade steel according to claim 1, characterized in that: The step 10 specifically includes: using a baler to pack the stripped cold-rolled steel coils.

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