GB/T 5614-1985 Names, definitions and codes of heat treatment conditions of cast iron parts GB/T5614-1985 standard download decompression password: www.bzxz.net

1.2 The designations definitions and symbols forheat treatment tempers of iron castings1.1 The names and definitions of heat treatment tempers of iron castings are determined according to different heat treatment processes. UDC 621.741.72/.73)GB5614--851.2 The codes of the basic heat treatment tempers of iron castings are represented by the first capital letter of the Chinese phonetic spelling of the tempers. When the letters of the codes of two or more names are the same, a lowercase letter can be added to distinguish them. The codes are placed in parentheses "()" and marked after the cast iron grade. 1.3 When a certain cast iron is subjected to several heat treatments, the codes of the tempers can be marked in sequence according to the process sequence and separated by dots "."
1.4 When the basic heat treatment state needs to be subdivided, the Arabic numerals following the code of the basic heat treatment name can be used to indicate the subdivided state. If further subdivision is required, Arabic numerals can still be used for further subdivision, and the two numbers must be separated by a horizontal line "-". 2 Names and definitions of heat treatment states of cast iron parts
2.1 As-cast
The state of the casting without any heat treatment.
2.2 Annealed state
2.2.1 High-temperature graphitization annealed state: The casting with eutectic cementite and free carbide in the as-cast structure is heated to above A, temperature, kept warm, and then furnace cooled to room temperature or furnace cooled to below A, temperature and air cooled to obtain pearlite, pearlite + ferrite matrix structure. 2.2.2 Low-temperature graphitization annealing state: The castings with pearlite and graphite or pearlite, ferrite and graphite in the as-cast structure are heated to a temperature slightly lower than A, kept warm, then furnace cooled to room temperature or furnace cooled to below A, air cooled to obtain a matrix structure dominated by ferrite. 2.3 Normalizing state
2.3.1 Complete austenitization normalizing state: The castings are heated to A, above, so that the matrix is ​​completely transformed into austenite, then air-cooled, wind-cooled or mist-cooled to obtain a matrix structure dominated by pearlite. 2.3.2 Low-carbon austenitization normalizing state: The castings are heated to a temperature slightly lower than A, kept warm, then quickly heated to a temperature higher than A, no heat preservation, air-cooled, wind-cooled or mist-cooled to obtain a basic structure of pearlite or pearlite and a small amount of ferrite. 2.3.3 Partial austenitization normalizing state: The casting is heated to A, and kept warm between A, and then taken out of the furnace and air-cooled, wind-cooled or mist-cooled to obtain a matrix structure of pearlite and ferrite.
2.4 Quenching state
2.4.1 Complete austenitization quenching state: The casting is heated to A, and kept warm to make the matrix completely transformed into austenite, then taken out of the furnace and quenched into the cooling medium to obtain a matrix structure mainly composed of martensite. 2.4.2 Low-carbon austenitization quenching state: The casting is heated to a temperature lower than A, and kept warm, and then quickly heated to a certain temperature higher than A without keeping warm, taken out of the furnace and put into the cooling medium to obtain a matrix structure mainly composed of martensite or martensite and a small amount of troostite. 2.4.3 Partial austenitic quenching state: The casting is heated to a temperature between A1 and A1, kept warm, and then taken out of the furnace and put into the cooling medium: a matrix structure mainly composed of martensite and a certain amount of ferrite is obtained. Issued by the National Bureau of Standards on November 25, 1985
Implementation on August 1, 1986
2.5 Tempering state
GB5614--85
2.5.1 High temperature tempering state: After quenching (or normalizing), the casting is heated to 500-600℃, kept warm, taken out of the furnace and air-cooled to obtain a tempered martensite basic structure (or stabilized structure). 2.5.2 Medium temperature tempering state: After quenching, the casting is heated to 350-500℃ and kept warm, taken out of the furnace and air-cooled to obtain a tempered magnetite matrix structure. 2.5.3 Low-temperature tempering state: After quenching, the casting is heated to 140-250℃, kept warm, and air-cooled to obtain a tempered martensite matrix structure.
2.6 Isothermal quenching state
2.6.1 Complete austenitization isothermal quenching: The casting is heated to above A, and kept warm. After the matrix is ​​completely transformed into austenite, it is taken out of the furnace and quenched in a constant temperature bath at a temperature below A, and kept warm. It is taken out and water-cooled or air-cooled to obtain a matrix structure with bainite as the main body. 2.6.2 Low-carbon austenitization isothermal quenching state: The casting is heated to a temperature slightly lower than A, and kept warm, and then quickly heated to a temperature higher than A, without keeping warm, and taken out of the furnace and quenched in a constant temperature bath at a temperature below A, and kept warm. It is taken out and water-cooled or air-cooled to obtain a matrix structure with bainite or bainite and a small amount of troostite as the main body. 2.6.3 Partial austenitization isothermal quenching state: The casting is heated to a temperature between Ac, and A, and then quenched into a constant temperature bath at a temperature below AF, and then taken out for water cooling or air cooling to obtain a bainite and ferrite matrix structure. 2.7 Aging state
2.7.1 Aging state: The casting is heated to a certain temperature range of plastic deformation (generally 500600℃) and kept warm, then slowly furnace cooled to below 300℃, and then air cooled out of the furnace to reduce the casting residual stress. 2.7.2 Natural aging state: The casting is placed at room temperature for a long time for more than 6 months to reduce the casting residual stress. 2.8 Surface quenching state
The casting surface is quickly heated to a temperature above A, and then quickly cooled to obtain a matrix structure of martensite on the surface of the casting. Due to different heating methods, it is usually divided into flame heating surface quenching, induction heating surface quenching, and electric contact heating surface quenching. 2.9 Chemical heat treatment state
The casting is placed in a certain chemical medium and goes through three stages of heating, heat preservation and cooling, so that certain elements in the medium (such as nitrogen, boron, etc.) penetrate into the surface of the casting, causing changes in organization and composition, and obtaining special physical and chemical properties and mechanical properties. Note: A: The temperature at which ferrite is completely transformed into austenite during heating. A: The temperature at which austenite is completely transformed into pearlite and ferrite during cooling. Ac: The temperature at which austenite begins to form during heating. 3 Codes for basic states and their subdivided states
3.1 Codes for basic states
Z~—Casting state
T—Annealing state
Zh——Normalizing state
C-——Quenching state
H—Tempering state
D~—Isothermal quenching state
S—Aging state
BSurface quenching state
Hu -Chemical heat treatment state
3.2 Subdivision of the code for the basic heat treatment state
3.2.1 Subdivision of the code for the annealing state
T,——High temperature graphitization annealing state
T2——Low temperature graphitization annealing state
3.2.2 Subdivision of the code for the normalizing state
Complete austenitization normalizing state
——Low carbon austenitization normalizing state
Z,——Part Austenitizing normalizing state
3.2.3 Codes for subdivided quenching state
Complete austenitizing quenching statewww.bzxz.net
Low carbon austenitizing quenching state
Partial austenitizing quenching state
Codes for subdivided austempering state
Complete austempering state
Low carbon austempering quenching state
Partial austempering quenching state
GB 5614—85
Complete austempering upper bainite state Complete austempering lower bainite state Low carbon austempering upper bainite state Low carbon austempering lower bainite state D31
Partial austempering upper bainite state D3 -2 ---
Bainite isothermal quenching state under partial austenitization 3.2.5
Subdivided code for tempering state
High temperature tempering state
Medium temperature tempering state
Low temperature tempering state
Subdivided code for aging state
Artificial aging state
Natural aging state
Subdivided code for surface quenching state
Flame heating surface quenching state|| tt||B2——-Induction heating surface quenching state
B2-1—High frequency induction heating surface quenching stateB2-2
Medium frequency induction heating surface quenching state
B.--Electric contact heating surface quenching state
3.2.8 Codes for subdivided chemical heat treatment states
Mononitriding state
Hu2 soft nitriding state
-Boriding state
HT200 (S,)
Code for artificial aging state
Gray cast iron grade
QT700-2
2(Zh·H)
Code for normalizing and tempering state
·Spheroidal graphite cast iron grade
QT1200-1
Additional instructions:
(D1-2)
GB 5614--85
-Code for bainite isothermal quenching state under complete austenitization Spheroidal graphite cast iron grade
This standard was proposed by the Ministry of Machinery Industry of the People's Republic of China and is under the jurisdiction of the Shenyang Foundry Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Shenyang Foundry Research Institute of the Ministry of Machinery Industry and Zhejiang University. The main drafters of this standard are Sun Liwei, Zhang Xiaokong, Yang Jiarong and Jiang Zhenxiong. 35
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