阅读说明：本技术 一种不锈钢的固溶热处理工艺 (Solution heat treatment process for stainless steel ) 是由 马杰 于 2019-09-29 设计创作，主要内容包括：本发明涉及一种不锈钢的固溶热处理工艺；其特征在于,包括以下步骤：步骤1、热处理炉加热至初始温度；步骤2、将不锈钢均匀排列放入热处理炉内；步骤3、热处理炉按照120℃～150℃/min加热；热处理炉加热至1100℃；步骤4、热处理炉在1100℃下保温240min；步骤5、将不锈钢从处理炉内取出；不锈钢放入冰水混合物内冷却至室温。解决了现有方案造成的采用风冷进行降温时间较长降低了固溶热处理的效率和采用水冷进行降温无法获得较好的硬度范围等问题。(The invention relates to a solution heat treatment process of stainless steel; the method is characterized by comprising the following steps: step 1, heating a heat treatment furnace to an initial temperature; step 2, uniformly arranging the stainless steel and putting the stainless steel into a heat treatment furnace; step 3, heating the heat treatment furnace at the speed of 120-150 ℃/min; heating the heat treatment furnace to 1100 ℃; step 4, preserving the heat of the heat treatment furnace at 1100 ℃ for 240 min; step 5, taking the stainless steel out of the treatment furnace; the stainless steel is placed in an ice-water mixture and cooled to room temperature. The problems that the efficiency of solid solution heat treatment is reduced due to long cooling time by adopting air cooling and a better hardness range cannot be obtained due to cooling by adopting water cooling in the prior art are solved.)

1. The solution heat treatment process for stainless steel is characterized by comprising the following steps of:

Step 1, heating a heat treatment furnace to an initial temperature;

Step 2, uniformly arranging the stainless steel and putting the stainless steel into a heat treatment furnace;

step 3, heating the heat treatment furnace at the speed of 120-150 ℃/min; heating the heat treatment furnace to 1100 ℃;

step 4, preserving the heat of the heat treatment furnace at 1100 ℃ for 240 min;

Step 5, taking the stainless steel out of the treatment furnace; the stainless steel is placed in an ice-water mixture and cooled to room temperature.

2. The solution heat treatment process of stainless steel according to claim 1, characterized in that: the stainless steels are uniformly arranged in the heat treatment furnace at intervals of 50 mm; the total weight of the stainless steel in the heat treatment furnace is less than 1000 kg.

3. the solution heat treatment process of stainless steel according to claim 1, characterized in that: temperature measuring devices are uniformly arranged in the heat treatment furnace.

4. A solution heat treatment process of stainless steel according to claim 3, characterized in that: the temperature measuring device is a thermocouple.

5. The solution heat treatment process of stainless steel according to claim 1, characterized in that: in the step 1, the initial temperature is more than 100 ℃ and less than or equal to 200 ℃.

Technical Field

The invention relates to a heat treatment process, in particular to a solution heat treatment process for stainless steel.

background

In general, heat treatment refers to a process of heating a metal in the solid state by means of heating, holding and cooling to obtain a desired texture and properties. These processes are linked to each other and are not interruptible. Stainless steels are of a wide variety of types, with austenitic stainless steels having good toughness, weldability and corrosion resistance. The heat treatment method of austenitic stainless steel generally adopts solution treatment, namely, the austenitic stainless steel is heated to 1050-1150 ℃, and then water cooling or air cooling is carried out to obtain a single-phase austenitic structure. Better metallographic structure and proper hardness can be obtained by adopting air cooling, but the air cooling time is longer. The cooling time can be shortened by adopting water cooling, but the hardness of the material is higher. How to shorten the cooling time becomes crucial in ensuring metallographic structure and hardness.

according to the existing scheme, the stainless steel is cooled by adopting a water cooling or air cooling mode after being heated and insulated. Such a solution has the following problems: (1) the air cooling is adopted for cooling, the cooling time is longer, and the efficiency of the solid solution heat treatment is reduced; (2) the water cooling is adopted for cooling, and a better hardness range cannot be obtained.

Disclosure of Invention

Aiming at the defects of the prior art, the invention discloses a solid solution heat treatment process for stainless steel, which aims to solve the problems that the efficiency of solid solution heat treatment is reduced due to long cooling time by adopting air cooling, a good hardness range cannot be obtained due to cooling by adopting water cooling and the like in the prior art.

The technical scheme adopted by the invention is as follows:

a solution heat treatment process of stainless steel; the method comprises the following steps:

step 1, heating a heat treatment furnace to an initial temperature;

step 2, uniformly arranging the stainless steel and putting the stainless steel into a heat treatment furnace;

Step 3, heating the heat treatment furnace at the speed of 120-150 ℃/min; heating the heat treatment furnace to 1100 ℃;

Step 4, preserving the heat of the heat treatment furnace at 1100 ℃ for 240 min;

Step 5, taking the stainless steel out of the treatment furnace; the stainless steel is placed in an ice-water mixture and cooled to room temperature.

The further technical scheme is as follows: the stainless steels are uniformly arranged in the heat treatment furnace at intervals of 50 mm; the total weight of the stainless steel in the heat treatment furnace is less than 1000 kg.

The further technical scheme is as follows: temperature measuring devices are uniformly arranged in the heat treatment furnace.

The further technical scheme is as follows: the temperature measuring device is a thermocouple.

The further technical scheme is as follows: in the step 1, the initial temperature is more than 100 ℃ and less than or equal to 200 ℃.

the invention has the following beneficial effects: the invention designs a solid solution heat treatment process for stainless steel, which adopts an ice-water mixture to cool, can ensure the uniform metallographic structure and better hardness range, and simultaneously realize rapid cooling. The solution heat treatment process of stainless steel brings the following effects: (1) the rapid cooling can be realized under the condition of ensuring the uniform metallographic structure and a better hardness range; (2) the efficiency of the solution heat treatment process is improved by preheating the heat treatment furnace; (3) the carbide of the stainless steel reaches a saturated state through a solution heat treatment process; (4) the microstructure is completely transformed and the metallographic structure is homogenized by long-time heat preservation.

drawings

FIG. 1 is a temperature profile of a solution heat treatment process according to a first embodiment of the present invention.

FIG. 2 is a temperature profile of a solution heat treatment process according to a second embodiment of the present invention.

Detailed Description

The following describes a specific embodiment of the present embodiment with reference to the drawings.

The invention discloses a solution heat treatment process for stainless steel. The solution heat treatment process of the stainless steel comprises the following steps:

Step 1, heating a heat treatment furnace to an initial temperature;

step 2, uniformly arranging the stainless steel and putting the stainless steel into a heat treatment furnace;

Step 3, heating the heat treatment furnace at the speed of 120-150 ℃/min; heating the heat treatment furnace to 1100 ℃;

step 4, preserving the heat of the heat treatment furnace at 1100 ℃ for 240 min;

Step 5, taking the stainless steel out of the treatment furnace; the stainless steel is placed in an ice-water mixture and cooled to room temperature.

the stainless steels are uniformly arranged in the heat treatment furnace at intervals of 50 mm. The total weight of the stainless steel in the heat treatment furnace is less than 1000 kg.

temperature measuring devices are uniformly arranged in the heat treatment furnace. Preferably, the temperature measuring device is a thermocouple. In the step 1, the initial temperature is higher than 100 ℃ and lower than or equal to 200 ℃;

The selection of the type of heat treatment furnace is common knowledge. The skilled person can select the type of heat treatment furnace RT-90-12 according to the working condition of the device.

Preferably, the stainless steel is 316L austenitic stainless steel.

The solution heat treatment process requires preheating a heat treatment furnace and then placing stainless steel in the heat treatment furnace. The preheating time in the heat treatment furnace is longer, and the time of the solution heat treatment process of the stainless steel can be accelerated by preheating.

When the heat treatment furnace is preheated, the stainless steel is uniformly arranged on a processing plate of the heat treatment furnace at intervals of 50 mm. And when the heat treatment furnace finishes preheating, the processing plate moves the stainless steel into the heat treatment furnace for heating.

the stainless steel is uniformly arranged at intervals of 50mm, so that the stainless steel can be uniformly heated. Meanwhile, the total weight of the stainless steel is limited, and the heat treatment effect of the stainless steel is ensured.

Thermocouples are arranged at the left end, the right end, the upper end, the lower end, the front end and the rear end of the heat treatment furnace. Thermocouples were mounted on the heat treatment furnace at 1000mm intervals. Thermocouples measure temperature at various locations. The thermocouple is arranged on the heat treatment furnace, and the temperature in the heat treatment furnace can be directly measured by adopting the thermocouple. The thermocouple can be used for accurately measuring the temperature in the heat treatment furnace. The temperature change in the heat treatment furnace can be accurately known through the thermocouple.

The choice of thermocouple type is common knowledge. Those skilled in the art can select the type of thermocouple, WRN-122, for example, according to the operation of the device.

The stainless steel is put into a heat treatment furnace and then is rapidly heated at the speed of 120-150 ℃/min. Until the temperature in the heat treatment furnace reached 1100 ℃. And (5) preserving the temperature of the stainless steel in a heat treatment furnace for 240 min.

And (3) keeping the temperature for 240min to heat the stainless steel and keep the temperature inside and outside the stainless steel consistent, so that the microstructure is completely transformed, and meanwhile, the metallographic structure of the stainless steel is homogenized.

The processing plate takes out the stainless steel from the heat treatment furnace. And (3) putting the stainless steel into the ice-water mixture for rapid cooling. The ice-water mixture is a mixture of ice cubes and water, and the ice cubes are uniformly dissolved in the water. The temperature of the ice-water mixture is 0 to 1 ℃. The temperature of the ice-water mixture is low, and the temperature of the stainless steel can be quickly reduced by the ice-water mixture.

The stainless steel is subjected to solution heat treatment to completely or basically dissolve carbides in the stainless steel. The carbides are solid-dissolved in the stainless steel and then rapidly cooled to room temperature, so that the carbides reach a saturated state.

Meanwhile, the stainless steel subjected to solution heat treatment has strong corrosion resistance. The stainless steel subjected to solution heat treatment has a uniform structure and a reduced hardness. The hardness of the stainless steel after cooling by the ice-water mixture was lower than that of the stainless steel after ordinary water cooling.

the hardness data of stainless steel cooled by water cooling is shown in table 1, and the hardness data in table 1 is the data value of five experiments.

table 1: hardness data of stainless steel cooled by water

number of measurements	1	2	3	4	5	mean value of
							Hardness value/HBW	172	175	181	185	189	180

the hardness data of stainless steel cooled by air cooling is shown in table 2, and the hardness data in table 2 are the data values of five experiments.

table 2: hardness data of stainless steel cooled by air cooling

number of measurements	1	2	3	4	5	Mean value of
							hardness value/HBW	135	138	142	138	140	139

The solution heat treatment process of the present invention is illustrated below with two examples: