> For the complete documentation index, see [llms.txt](https://dante-solutions-inc.gitbook.io/dante-6.3-help-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dante-solutions-inc.gitbook.io/dante-6.3-help-documentation/readme/material-database/steel-alloy-data/steel-material-precipitation-hardening-data-file.md).

# Steel Material Precipitation Hardening Data File

The carbide and alloy precipitation data needed to execute a DANTE model are contained in a file with the \*.PHAB extension for Standard materials and a \*.PHA extension for User materials; e.g., S41XX.PHAB or U41XX.PHA. An example file shown below indicates that the data are for the 4100 series steel. The data stored in the \*.PHAB file are in keyword format and include:

* Carbide A (alloy carbide) and Carbide C (iron carbide) decomposing in austenite as a function of temperature;
* Minimum and maximum sizes for Carbides A and C;
* Shape factor to account for the effect of carbide shape on dissolution; and
* Coarsening parameters for Carbides A and C.

An example file is shown below and has multiple data entries for the decomposition of carbides in austenite as a function of temperature. The keyword definitions follow the example.

```
	*MAT_DESCRIPTION 
	 Carbide Model property secondary hardening  (mm, kg)
	*MAT_VERSION
	 AUG2024
	*MAT_NAME
	 U41XX
	**
	****Temperature for Carbide Decomposing in Austenite
	** Three (3) data lines are required
	** 1st line: temperature
	** 2nd line: FE3C decomposing in aust
	** 3rd line: PPTA decomposing in aust
	*STEEL_AUST_CBDDCP
	 800.0
	 0.000, 1.00, 1.00
	 0.000, 1.50, 1.00
	*STEEL_AUST_CBDDCP
	 840.0
	 0.010, 1.00, 1.00
	 0.005, 1.50, 1.00
	*STEEL_AUST_CBDDCP
	 860.0
	 0.020, 1.00, 1.00
	 0.010, 1.50, 1.00
	*STEEL_AUST_CBDDCP
	 900.0
	 0.030, 1.00, 1.00
	 0.015, 1.50, 1.00
	**
	** CBD-C (Iron Carbide) Least and Max Critical Particle Sizes (unit: nm)
	** 1st line: Carbide C (GE3C) critic size, least, max and  extreme
	** 2nd line: Precipitate A (PPTA) critic size, least, max and  extreme
	*STEEL_TMCBD_CRTSIZ
	 2.0,  50.0,   200.0 
	 1.0,  25.0,   100.0
	** -----------------------------------
	** Shape Factor of Carbides [1.0, 10.0] with 1.0 being perfect round
	** shape factor {1,10] for CBDC, CBDA
	*STEEL_TMCBD_SHPFACTR
	 1.0, 5.5
	** -----------------------------------
	** Ratio of carbon volume fraction in carbides [0,1]: CBDC, CBDA 
	*STEEL_CBD_CRBWGTR
	 0.0667, 0.10
	** -----------------------------------
	**~~Carbides Coarsening Model Parameters
	** Temp LBound,Temp UBound, C1, C2, C3, C4 
	** coarsening coefficient: c1+c2*exp((T-c4)/c3)  c3>1.0
	*STEEL_TMCBD_CCRSN
	 50.0, 700.0, 0.0, 0.25, 42.5, 200.0
	**~~CBD-A Coarsening Model Parameters
	*STEEL_TMCBD_ACRSN
	 50.0, 700.0, 0.0, 0.100, 4.5, 525.0 
	** -----------------------------------
	**~~Austenite Grain Size Coarsening Model and Parameters
	** Temp LBound,Temp UBound, n, C1, C2, C3, C4 
	** Coefficient: (dt)^n-(d0)^n = c1+c2*exp((T-c4)/c3)  c3>1.0
	*STEEL_AUST_GSCRSN
	 800.0, 1300.0, 3.0, 0.0, 5.E-09, 95.0, 950.0 
	** Austenite Grain Size Refinement (0.0, 1.0]
	** FERR, PEAR, UBAIN, LBAIN, MART, TMART
	*STEEL_AUST_GSREFN
	 1.00, 1.00, 0.95, 0.90, 0.50, 0.75 
	****************** END OF FILE ******************
```

\*\* \*\*

***PRECIPITATION FILE KEYWORD DESCRIPTIONS*** ***\*MAT\_DESCRIPTION***: Text description of the data contained in the file.\*\* \*\*

***\*MAT\_VERSION***: The version of the DANTE material database. **This value should not be modified. Software will not function properly if changed.**

***\*MAT\_NAME***: Name of the material in the DANTE material database. **This value should not be modified unless a new or modified material is being created.** If a new material is created in the User Database (UDB subdirectory), the material name must be unique, have a maximum of 36 characters (no spaces or special characters; underscore “\_” and hyphen “-” are acceptable), and be all capital letters.

***\*STEEL\_AUST\_CBDDCP***: Describes the decomposing rate of Carbide C (iron carbide) and Carbide A (alloy carbide) in austenite at a given temperature. Multiple instances of this keyword are required to define the decomposing behavior at different temperatures.

***\*STEEL\_TMCBD\_CRTSIZ***: Defines the smallest (1^(st) value) and largest (3^(rd) value) sizes Carbides A and C can achieve. The 2^(nd) value defines the size of a “stable” carbide, which is difficult to decompose. The unit is µm.

***\*STEEL\_TMCBD\_SHPFACTR***: Defines the effect of carbide shape on its ability to dissolve for Carbides A and C. Spherical shapes dissolve the most rapidly and are represented by a value of 1. A value of 10 is representative of a shape consisting of sharp angles (requiring more energy to dissolve).

***\*STEEL\_CBD\_CRBWGTR***: Defines the normalized amount of carbon, for Carbides A and C, that can be taken by a single carbide type. A value of one (1) indicates that all available carbon can go to carbide form and a value of zero (0) indicates that no available carbon can go to carbide form.

***\*STEEL\_TMCBD\_CCRSN***: Describes the coarsening behavior of Carbide C in tempered martensite.

***\*STEEL\_TMCBD\_ACRSN***: Describes the coarsening behavior of Carbide A in tempered martensite.