What is aluminum temper?
The aluminum temper designation is composed of letters and numbers that indicate what type of tempering treatment the aluminum alloy has undergone, placed after the aluminum alloy name and separated by dashes.
For example, 3003-h14, 3003 refers to the alloy grade, h14 refers to the tempered state.
It is important to understand the meaning of aluminum tempers
Understanding the meaning of aluminum temper designations is critical to selecting the correct aluminum. The temper designation tells producers and users how to mechanically or heat treat the alloy to obtain the desired properties.
Even for the same aluminum alloy, if it is tempered differently, its mechanical properties will be completely different.
The specific meaning of aluminum tempers
The tempering designation is represented by 1 letter and a series of numbers, the letter represents the temper type, These numbers show exactly how well the tempering method is performing.
There are 5 kinds of tempering types, represented by 5 letters:
- H: work hardened
- O: Full annealing
- T: heat treatment
- W: Solution heat treatment
- F: Free machining
See the table below for specific explanations:
| Temper types | introduction |
| H: work hardened | It is suitable for products whose strength is increased through work hardening. After work hardening, the product may or may not undergo additional heat treatment to reduce the strength. |
| O: Full annealing | Suitable for processed products that have been fully annealed to obtain the lowest strength. |
| T: heat treatment | It is suitable for products that have been stabilized by (or without) work hardening after heat treatment. The T code must be followed by one or more Arabic numerals (generally for heat-treated reinforced materials) |
| W: Solution heat treatment | An unstable state, which is only applicable to alloys that are naturally aged at room temperature after solution heat treatment. This state code only indicates that the product is in the natural aging stage. |
| F: Free machining | It is suitable for products that have no special requirements for work hardening and heat treatment conditions during the forming process, and the mechanical properties of products in this state are not specified. |
Detailed description of each temper type
| H state subdivision | |
| The first digit after H indicates the method of work hardening treatment | |
| H1 | The pure work hardening state is suitable for the state in which the required strength can be obtained only by work hardening without additional heat treatment. |
| H2 | The state of work hardening and incomplete annealing is suitable for products whose strength is reduced to the specified index after incomplete annealing after the degree of work hardening exceeds the specified requirements of the finished product. |
| H3 | The state of work hardening and stabilization treatment is suitable for products whose mechanical properties have been stabilized by low temperature heat treatment after work hardening or due to the heating effect during processing. |
| H4 | The state of work hardening and painting treatment applies to products that have been incompletely annealed due to painting treatment after work hardening. |
| The second digit after H indicates the hardening degree of the material. Generally, the hardening degree is divided into 8 grades, 1 is the lowest, 8 is the highest, and 9 represents a superhard state with a higher degree of work hardening than Hx8. |
|
| H12 | Work hardened to 25% hardness |
| H14 | Work hardened to 50% hardness |
| H16 | Work hardened to 75% hardness |
| H18 | Work hardened to 100% hardness (fully hardened state) |
| H19 | super work hardened state. The tensile strength of this material should be 10N/mm2 or more higher than that of the H18 state material |
| H22 | Partially annealed to 25% hardness after work hardening |
| H24 | Partially annealed to 50% hardness after work hardening |
| H26 | Partially annealed to 75% hardness after work hardening |
| H28 | Partially annealed to 100% hardness after work hardening |
| H32 | Stabilized to 25% hardness after work hardening |
| H34 | Stabilized to 50% hardness after work hardening |
| H36 | Stabilized to 75% hardness after work hardening |
| H38 | Stabilized to 100% hardness after work hardening |
| H42 | Painted after work hardening, 25% hardness treatment |
| H44 | Painted after work hardening, 50% hardness treatment |
| H46 | Painted after work hardening, 75% hardness treatment |
| H48 | Work-hardened painted, 100% hardened |
| HXXX status | |
| H111 | It is suitable for products that have undergone appropriate amount of work hardening after final annealing, but the degree of work hardening is not as good as that of H11 state. |
| H112 | It is suitable for products formed by thermal processing, and the mechanical properties of products in this state have specified requirements. |
| H116 | It is suitable for products made of 5XXX series alloys with magnesium content ≥ 4.0%. These products have specified mechanical properties and exfoliation corrosion resistance performance requirements. |
| O state subdivision | |
| O1 | A state in which the processed material is held at about the same temperature as the solution heat treatment for an equal period of time, and then slowly cooled to room temperature. |
| O2 | In order to improve the formability of the material, a deformation treatment state of superplastic processing (SPF) is performed. |
| O3 | The homogenized state. |
| T state subdivision | |
| TX status (0-10 numbers after T indicate the heat treatment procedure for the product) |
|
| T0 | After solution heat treatment, after natural aging and then through cold working state, it is suitable for products whose strength has been improved by cold working. |
| T1 | Cooled by the high temperature forming process, and then naturally aged to a basically stable state , it is suitable for products that are cooled by the high temperature forming process and no longer undergo cold processing (straightening, leveling, but not affecting the limit of mechanical properties). |
| T2 | Cooled by the high temperature forming process, naturally aged to a basically stable state after cold processing, it is suitable for products that are cooled by the high temperature forming process and then cold processed or straightened to improve strength. |
| T3 | Cold working after solution heat treatment, and then natural aging to a basically stable state is suitable for products that are cold worked or straightened to improve strength after solution heat treatment. |
| T4 | Natural aging to a basically stable state after solution heat treatment is suitable for products that are no longer cold-worked after solution heat treatment (straightening, leveling, but not affecting the limit of mechanical properties). |
| T5 | The state of cooling by high temperature forming process and then artificial aging is suitable for products that are artificially aged after being cooled by high temperature forming process without cold processing (straightening and leveling can be performed, but the limit of mechanical properties is not affected). |
| T6 | The state of artificial aging after solution heat treatment is suitable for products that do not undergo cold processing after solution heat treatment (straightening and leveling can be performed, but the mechanical property limit is not affected). |
| T7 | The state of overaging after solution heat treatment is suitable for products whose strength exceeds the highest peak point on the aging curve during artificial aging in order to obtain some important characteristics after solution heat treatment. |
| T8 | The state of cold working after solution heat treatment and then artificial aging is suitable for products that have been cold worked or straightened and leveled to increase strength. |
| T9 | The state of artificial aging after solution heat treatment and then cold working is suitable for products whose strength has been improved by cold working. |
| T10 | The state of cooling by high temperature forming process, then cold working, and then artificial aging is suitable for products that have been straightened and leveled by cold working to improve strength. |
| TXX state and TXXX state (indicates the state that has undergone specific process treatment that significantly changes product characteristics <such as mechanical properties, corrosion resistance, etc.) |
|
| T42 | It is suitable for products that have been naturally aged to a fully stable state after solution heat treatment in O or F state, and is also suitable for products whose mechanical properties have reached T42 state after heat treatment for processed products in any state of the buyer. |
| T62 | It is suitable for products that undergo artificial aging after solution heat treatment from O or F state, and also applies to products whose mechanical properties reach T62 state after heat treatment of processed products in any state by the purchaser. |
| T73 | It is suitable for products that undergo aging to achieve the specified mechanical properties and stress corrosion resistance after solution heat treatment. |
| T74 | Same as T73 state definition. The tensile strength of this state is greater than that of T73 state, but less than that of T76 state. |
| T76 | Same as T73 state definition. The tensile strength of this state is higher than that of T73 and T74 states, and the stress corrosion cracking resistance is lower than that of T73 and T74 states, but its exfoliation corrosion resistance is still good. |
| T7X2 | It is suitable for products that have undergone artificial overaging treatment after solution heat treatment in O or F state, and whose mechanical properties and corrosion resistance have reached T7X state. |
| T81 | It is suitable for products that are subjected to about 1% cold deformation after solution heat treatment to improve strength, and then artificially aged. |
| T87 | It is suitable for products that after solution heat treatment, increase the strength by about 7% cold deformation, and then perform artificial aging. |
| Stress Relief Status (add "51", "510", "511", "52", "54" after TX or TXX or TXXX status) |
|
| TX51
TXX51 TXXX51 |
Applicable to thick plates, rolled or cold-finished bars and die forgings, forged rings or rolled rings, which are stretched according to the specified amount after solution heat treatment or cooling from high-temperature forming processes. These products are no longer stretched after stretching Straighten. The permanent deformation of thick plates is 1.5% to 3%; the permanent deformation of rolled or cold finished bars is 1% to 3%; the permanent deformation of die forgings, forged rings or rolled rings is 1% to 5% %. |
| TX510 TXX510 TXXX510 |
Applicable to extruded rods, profiles and tubing that are solution heat treated or cooled from a high temperature forming process and stretched to a specified amount, as well as drawn tubing that are not straightened after stretching. The permanent deformation of extruded rods, shapes and pipes is 1% to 3%; the permanent deformation of drawn pipes is 1.5% to 3%. |
| TX52 TXX52 TXXX52 |
It is suitable for products with a permanent deformation of 1% to 5% after solution heat treatment or high temperature forming process to relieve stress by compression. |
| TX54 TXX54 TXXX54 |
Suitable for die forgings that are stress relieved by cold shaping in the final forging die. |