Method for optimizing grain boundary characteristic distribution of 316L austenitic stainless steel

Abstract

Provided is a method for optimizing grain boundary characteristic distribution of 316L austenitic stainless steel. The method includes the following steps that (1), the shape of a 316L stainless steelmember is adjusted, the upper and lower sides of the member need to be repaired to be flat and symmetrical; (2), the member is placed in a resistance furnace with the temperature being 1050-1150 DEGC for heat preservation for 60-90 minutes, and then material is taken out and subjected to water quenching; (3), the member is subjected to unidirectional compression deformation at room temperature,the deformation rate is 0.1-10 s<1>, and the deformation amount is 3%-6%; and (4), the deformed member is subjected to subsequent annealing treatment, the annealing temperature is controlled to 1080-1150 DEG C, and the annealing time is 90-110 min, and after the annealing is completed, the member is taken out and subjected to the water quenching. The optimized 316L austenitic stainless steel has alow [sigma] coincidence site lattice grain boundary ratio more than 80%, and the increase amplitude is significant; and multiple low [sigma] coincidence site lattice grain boundary clusters are formed, and the intergranular corrosion resistance performance of the material is significantly improved.

Description

technical field

[0001] The invention belongs to the technical field of materials, and relates to a method for optimizing the grain boundary structure of austenitic stainless steel. Background technique

[0002] Austenitic stainless steel is the most important type of stainless steel, and its output accounts for about 70% of the total stainless steel output. 316 series stainless steel is the most widely used type of austenitic stainless steel, with good processing performance, welding performance, mechanical properties and non-magnetic properties; 316L stainless steel is a low-carbon version of 316 stainless steel, with a carbon content close to 0.08%. The carbon content of 316 stainless steel, 316L stainless steel is less than 0.03%, and the reduction of carbon content makes the material have better resistance to intergranular corrosion. However, materials can still fail in complex and severe application environments. Statistics show that the corrosion of austenitic stainl...

Examples

Embodiment 1

[0018] The material of the component in this example is 316L austenitic stainless steel, and the initial grain boundary structure of the material is as follows: figure 1 As shown, most of its grain boundaries are black large-angle random grain boundaries, and a small part are light-colored low-Σ weight lattice grain boundaries, and the proportion of special grain boundaries is about 70%; according to the deformation heat treatment process described in the patent The grain boundary structure after treatment is as figure 2 As shown, the light-colored low-Σ-heavy lattice grain boundaries were significantly increased and interconnected into low-Σ grain boundary clusters, the proportion of which increased to 85%.

[0019] The specific process steps of this embodiment are:

[0020] Adjust the shape of the 316L stainless steel workpiece, and trim the upper and lower sides to be parallel. Then, solution treatment was performed in a resistance furnace at 1100 °C for 60 minutes. Afte...

Embodiment 2

[0022] This example uses the same initial state 316L stainless steel material as Example 1, and its grain boundary structure is the same as Example 1 (such as figure 1 shown). The grain boundary structure treated according to the process described in the patent is as follows: image 3 As shown, the light-colored low-Σ-heavy lattice grain boundaries are significantly increased and interconnected into low-Σ grain boundary clusters, the proportion of which increases to 86%.

[0023] The specific process of this embodiment is:

[0024] After shape trimming, the 316L stainless steel was placed in a resistance furnace at 1100°C for solution treatment for 70 minutes. Take the sample to 1 s -1 The deformation rate was unidirectional compression deformation at room temperature, and the deformation was stopped when the deformation amount reached 5%. The sample was taken out and placed in a resistance furnace at 1100 °C for 100 minutes, and then the material was taken out and water qu...

technical field

[0001] The invention belongs to the technical field of materials, and relates to a method for optimizing the grain boundary structure of austenitic stainless steel. Background technique

[0002] Austenitic stainless steel is the most important type of stainless steel, and its output accounts for about 70% of the total stainless steel output. 316 series stainless steel is the most widely used type of austenitic stainless steel, with good processing performance, welding performance, mechanical properties and non-magnetic properties; 316L stainless steel is a low-carbon version of 316 stainless steel, with a carbon content close to 0.08%. The carbon content of 316 stainless steel, 316L stainless steel is less than 0.03%, and the reduction of carbon content makes the material have better resistance to intergranular corrosion. However, materials can still fail in complex and severe application environments. Statistics show that the corrosion of austenitic stainl...

Examples

Embodiment 1

[0018] The material of the component in this example is 316L austenitic stainless steel, and the initial grain boundary structure of the material is as follows: figure 1 As shown, most of its grain boundaries are black large-angle random grain boundaries, and a small part are light-colored low-Σ weight lattice grain boundaries, and the proportion of special grain boundaries is about 70%; according to the deformation heat treatment process described in the patent The grain boundary structure after treatment is as figure 2 As shown, the light-colored low-Σ-heavy lattice grain boundaries were significantly increased and interconnected into low-Σ grain boundary clusters, the proportion of which increased to 85%.

[0019] The specific process steps of this embodiment are:

[0020] Adjust the shape of the 316L stainless steel workpiece, and trim the upper and lower sides to be parallel. Then, solution treatment was performed in a resistance furnace at 1100 °C for 60 minutes. Afte...

Embodiment 2

[0022] This example uses the same initial state 316L stainless steel material as Example 1, and its grain boundary structure is the same as Example 1 (such as figure 1 shown). The grain boundary structure treated according to the process described in the patent is as follows: image 3 As shown, the light-colored low-Σ-heavy lattice grain boundaries are significantly increased and interconnected into low-Σ grain boundary clusters, the proportion of which increases to 86%.

[0023] The specific process of this embodiment is:

[0024] After shape trimming, the 316L stainless steel was placed in a resistance furnace at 1100°C for solution treatment for 70 minutes. Take the sample to 1 s -1 The deformation rate was unidirectional compression deformation at room temperature, and the deformation was stopped when the deformation amount reached 5%. The sample was taken out and placed in a resistance furnace at 1100 °C for 100 minutes, and then the material was taken out and water qu...

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