Hollomon_parameter

Consecutive heat-treatment cycles

How ramp data is used

Heating/cooling rate determines the real ramp duration and the slope of the time–temperature diagram.

Ramp contribution to Hp is a separate, optional equivalent-time correction. The published implementation used here is limited to the C = 20 form.

Still-air release below the controlled-cooling transition is identified, but no fictitious cooling time is added without measured thermal data.

Report information entered once and reused throughout the calculation and engineering report

Report title Report reference Project / client Equipment / component

Material / material family Select an EN, EN 10213 or ASME/ASTM material. The catalogue Pcrit is shown after selection.

Procedure / code reference

Governing wall thickness

Used for tempering records and automatic heating/cooling-rate rules.

Prepared by Report date Notes / assessment context

ASME B31.1 Grade 91 PWHT assessment Automatically enabled for Grade 91 / P91 / T91 / WP91 / F91 / C12A.

P-No. 15E, Group 1

ASME B31.1 edition Maximum holding-temperature basis Apply Note (6) reduced minimum temperature Permits 675°C minimum only when nominal material thickness is ≤13 mm.

The entered governing wall thickness is used as the B31.1 control-thickness basis. It must be established by the responsible engineer in accordance with para. 132.4.1.

Cycle / condition	Holding temperature	Holding time	Heating rate	Cooling rate	Status

H–J constant, C

Cumulative-cycle method Each entered cycle is converted to an equivalent time at the highest cycle temperature. Equivalent times—not individual Hp values—are summed to obtain the cumulative Hp exposure. Governing thickness is mandatory for tempering records and automatic heating/cooling-rate rules.

Temperature unit Time unit Rate unit Profile base temperature, °C

Automatic presets calculate maximum controlled rates from governing thickness. The controlled profile is time-proportional; any release to still air below the preset transition temperature is identified separately and its duration is not invented.

Cumulative Hp result

Total Hp parameter

18.132 dimensionless

Enter one or more heat-treatment cycles to calculate the cumulative Hp exposure.

Equivalent holding conditions

Orientation at the calculated Hp and, when available, at the selected material Hp_max / Pcrit. Ramp contributions are not applied a second time.

Calculated condition

Current Hp

Hp = 18.132

Temperature	Equivalent time, min	Time in hours

Material limit orientation

Selected material Hp_max

Hp_max = —

Temperature	Equivalent time, min	Time in hours

Cycle contribution breakdown

All equivalent times refer to the automatically selected common reference temperature.

Cycle	Condition	Individual Hp	Effective time	Equivalent time	Contribution	Cumulative Hp

Engineering calculation aid only. This output is not an approved heat-treatment procedure, material qualification, code-compliance certificate or instruction to perform heat treatment. Verify all inputs, the selected H–J constant, governing thickness, empirical rate rule, holding requirements, material limits, applicable standard and approved procedure. Controlled cooling is plotted using the applied calculated rate; still-air cooling below a release temperature is identified but its unknown duration is excluded unless supported by measured thermal data. Final engineering approval remains with the responsible engineer and organisation.

Hollomon_parameter

Cumulative Hollomon–Jaffe Heat-Treatment Assessment

Consecutive heat-treatment cycles

ASME B31.1 Grade 91 PWHT assessment

Cumulative Hp result

Equivalent holding conditions

Current Hp

Selected material Hp_max

Hp exposure illustration

Cycle contribution breakdown

Hollomon_parameter

Cumulative Hollomon–Jaffe Heat-Treatment Assessment

Consecutive heat-treatment cycles

ASME B31.1 Grade 91 PWHT assessment

Cumulative Hp result

Equivalent holding conditions

Current Hp

Selected material Hp_max

Hp exposure illustration

Cycle contribution breakdown

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