CN102344999A - Method for determining tempering temperature - Google Patents

Abstract

The invention discloses a method for determining tempering temperature, which comprises the following steps: reading a relation table of tempering hardness-tempering temperature in a database according to a material of a part; and determining the tempering temperature according to the tempering hardness. The tempering temperature can be determined according to the material and the tempering hardness requirement inputted by users, so that the process design efficiency is enhanced and the design error can be avoided, the selection of tempering temperature is more reasonable without the phenomenon of columns crossing, the obtained technological parameter has good consistency, scientific and standard design result.

Description

A kind of method of definite tempering temperature

Technical field

What the present invention relates to is a kind of area of computer aided Design of Heat Treatment Process method, in particular a kind of method of definite tempering temperature.

Background technology

Workpiece was heated to the following a certain temperature of transformation temperature after the metal tempering process will harden often, the insulation certain hour, and cool to room temperature obtains a kind of thermal treatment process of specific mechanical properties then.

The key of tempering process establishment will be confirmed tempering temperature and tempering insulation time; When the tempering process of steel is worked out usually; Be net thickness, confirm tempering temperature and tempering insulation time when the part tempering process is handled according to final needed hardness requirement of part and part.And tempered-hardness and tempering temperature concern more complicated, it and the composition of material, inner tissue, the structural state before the tempering all have confidential relation, are difficult to describe with general mathematical function expression formula.Because the hardness after the tempering is difficult to accurate control, requires Hardness Control in the practice usually in a scope; There is error in tempering equipment to temperature controlling, and it also is a value in the interval that the control of tempering temperature is required.The tempering temperature in the practical applications and the relation of tempered-hardness are based on that data form that great number tested data obtains expresses.As shown in table 1, table 1 be after steel commonly used quench tempered-hardness-tempering temperature relation table.

Table 1 tempered-hardness-tempering temperature relation table (tempering temperature ℃)

Annotate: table 1 derives from Wang Xiankui, and " material and thermal treatment thereof ", mechanical workout handbook (reprint) ISBN 978-7-111-24249-9: the 265th page, the date of publication: on June 1st, 2008.

Traditional hand establishment tempering process mainly relies on above-mentioned table 1, and the technologist is according to the scope that the part tempered-hardness requires, and in table 1, searches near the temperature range of this durometer level, confirms suitable tempering temperature.In the actual process compilation process, because the material category that table 1 relates to is various, the hardness value that part requires is lack of standardization, and tempering temperature is not corresponding one by one with tempered-hardness in the table 1, often has the situation of striding row to occur.The tempered-hardness that the user requires is a scope normally, this durometer level interval maybe and table 1 in stiffness region between inconsistent, sometimes even can stride 2 intervals or more interval.

The appearance of above-mentioned situation causes the complicacy and the inefficiency of traditional hand establishment tempering process, and the consistence of the technology of technics institution and standardization are poor, and the efficient of process choice is lower usually.

Summary of the invention

Goal of the invention: the invention provides a kind of method of definite tempering temperature, design through CAPP (computer aided process planning) CAP process and realize confirming to tempering temperature.

Technical scheme: the present invention includes following steps: may further comprise the steps:

(1) according to tempered-hardness-tempering temperature relation table in the material reading database of part;

(2) confirm tempering temperature according to tempered-hardness, may further comprise the steps:

1) normalization tempered-hardness:

Whether the interval in the scope of judging tempering temperature and the step (1) in tempered-hardness-tempering temperature relation table is consistent, in this way, then confirms tempering temperature, as not being that the intermediate value of then getting original tempered-hardness scope is as the tempered-hardness H after standardizing _Tn

2) successively relatively the normalization after tempered-hardness H _TnWith the tempered-hardness upper limit and the tempered-hardness lower limit in tempered-hardness-tempering temperature relation table, judge the tempered-hardness H after standardizing _TnWhether on adjacent two tempered-hardness section boundaries on tempered-hardness-tempering temperature relation table;

3) the tempered-hardness H after normalization _TnNot on adjacent two tempered-hardness section boundaries, then find out the tempered-hardness H after the normalization _TnThe tempering temperature of the correspondence that the tempered-hardness that in tempered-hardness-tempering temperature relation table, belongs to is interval is interval, in this tempering temperature interval, calculates tempering temperature value T with approach based on linear interpolation _t

4) the tempered-hardness H after normalization _TnOn adjacent two tempered-hardness section boundaries, then judge whether it is the less energy-consumption principle, in this way, confirm that then tempering temperature is the low interval of temperature, as not being that then the through performance priority principle confirms that tempering temperature is the high interval of temperature;

5) the standardization tempering temperature is interval: step 3) obtains tempering temperature value T _t± 10 ℃ are standardization tempering temperature interval; The tempering temperature that obtains of step 4) is a value range, directly uses.

In the said step 3), approach based on linear interpolation is calculated T _tMethod be:

$T_t=T_{\mathrm{hd}}+(H_{\mathrm{tn}}-H_d)\×\frac{T_{\mathrm{hu}}-T_{\mathrm{hd}}}{H_u-H_d}$

H _d: H _TnThe interval upper limit of the tempered-hardness of correspondence in tempered-hardness-tempering temperature relation table,

H _u: H _TnThe interval lower limit of the tempered-hardness of correspondence in tempered-hardness-tempering temperature relation table,

T _Hd: the H in tempered-hardness-tempering temperature relation table _dCorresponding tempering temperature lower limit,

T _Hu: the H in tempered-hardness-tempering temperature relation table _uThe corresponding tempering temperature upper limit;

In the said step 4), the less energy-consumption priority principle is meant that selecting low tempering temperature, performance priority principle to be meant selects high tempering temperature.Under the prerequisite that guarantees the tempered-hardness required value, can save the energy; The performance priority principle is meant and selects higher tempering Heating temperature that higher temperature generally can be accelerated tissue inter-variable, accelerates the carbon diffusion process simultaneously, is guaranteeing under the prerequisite of hardness, improves intensity, plasticity and the toughness of material.

Beneficial effect: the present invention compares prior art and has the following advantages: the present invention only requires just can confirm tempering temperature according to the tempered-hardness of material and user's input; Improved technological design efficient; Avoided design mistake; More reasonable to choosing of tempering temperature; The phenomenon of row can not appear striding; The processing parameter high conformity that obtains, design result science, standard.

Description of drawings

Fig. 1 is main control process flow figure of the present invention;

Fig. 2 is the schema of step of the present invention (2).

Embodiment

Elaborate in the face of embodiments of the invention down, present embodiment provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment being to implement under the prerequisite with technical scheme of the present invention.

Embodiment 1

As depicted in figs. 1 and 2, present embodiment may further comprise the steps:

(1) part material of present embodiment is 40Cr; Tempered-hardness in the reading database-tempering temperature relation table; As shown in table 1; Tempered-hardness in the database-tempering temperature relation table is selected from Wang Xiankui; " material and thermal treatment thereof "; Mechanical workout handbook (reprint) ISBN 978-7-111-24249-9: the 265th page, 2008.6.1.

(2) requirement according to the tempered-hardness of user input is HRC42-52, confirms tempering temperature, comprising:

1) the normalization tempered-hardness requires: the tempered-hardness of user's input requires to stride 3 intervals or more interval;

Get original tempered-hardness scope and be intermediate value HRC47 that tempered-hardness that the user imports the requires tempered-hardness after as normalization;

Whether 2) tempered-hardness and the tempered-hardness upper limit and the tempered-hardness lower limit in tempered-hardness-tempering temperature relation table after the normalization relatively successively, the tempered-hardness after judgement is standardized be on adjacent two hardness section boundaries on tempered-hardness-tempering temperature relation table;

3) tempered-hardness after the normalization is not on adjacent two section boundaries; Then find out tempered-hardness after the normalization and require that tempering temperature corresponding in tempered-hardness-tempering temperature relation table is interval to be 300-340 ℃; In this tempering temperature interval, calculate the tempering temperature value with approach based on linear interpolation, the linear interpolation calculation formula is following:

$T_t=T_{\mathrm{hd}}+(H_{\mathrm{tn}}-H_d)\×\frac{T_{\mathrm{hu}}-T_{\mathrm{hd}}}{H_u-H_d}$

$=360+(47-45)\×\frac{300-340}{50-45}$

$=344$

T _t: the tempering temperature value that calculates,

H _Tn: the tempered-hardness after the normalization,

H _d: H _TnThe interval upper limit of the tempered-hardness of correspondence in tempered-hardness-tempering temperature relation table,

H _u: H _TnThe interval lower limit of the tempered-hardness of correspondence in tempered-hardness-tempering temperature relation table,

T _Hd: the H on tempered-hardness-tempering temperature relation table _dCorresponding tempering temperature lower limit,

T _Hu: the H in tempered-hardness-tempering temperature relation table _uThe corresponding tempering temperature upper limit;

The standardization tempering temperature is interval;

The tempering temperature T that the process step 3) calculates _tBe a determined value, handle the scene in the thermal treatment process of reality, need change into a scope to this value standard of confirming, this scope is a rule of thumb data, generally at T _t± 10 ℃ (344 ± 10 ℃) can meet the demands.Value after the standardization will check that simultaneously the heating-up temperature error of firing equipment can not surpass this scope, carries out temper based on the gained temperature to part.

Embodiment 2

(1) part material of present embodiment is Cr12; Tempered-hardness in the reading database-tempering temperature relation table; As shown in table 1; Tempered-hardness in the database-tempering temperature relation table is selected from Wang Xiankui; " material and thermal treatment thereof "; Mechanical workout handbook (reprint) ISBN 978-7-111-24249-9: the 265th page, 2008.6.1.

(2) requirement according to the tempered-hardness of user input is HRC47-53, confirms tempering temperature, comprising:

1) the normalization tempered-hardness requires: get original tempered-hardness scope and be intermediate value HRC50 that tempered-hardness that the user imports the requires tempered-hardness after as normalization;

Whether 2) tempered-hardness and the tempered-hardness upper limit and the tempered-hardness lower limit in tempered-hardness-tempering temperature relation table after the normalization relatively successively, the tempered-hardness after judgement is standardized be on adjacent two hardness section boundaries on tempered-hardness-tempering temperature relation table;

Tempered-hardness after normalization is on adjacent two section boundaries; Show and select different tempering temperatures can obtain identical tempering hardness value; The user is according to practical situation; Need the material require preferable performance after the tempering; Then select the performance priority principle to confirm tempering temperature, that is: tempering temperature is 480-520 ℃.

Use present method to confirm tempering temperature, carry out the part hardness that temper obtains and meet the demands fully, and wrong situation can not occur handling.

Claims (3)

1. the method for a definite tempering temperature is characterized in that, may further comprise the steps:

(1) according to tempered-hardness-tempering temperature relation table in the material reading database of part;

(2) confirm tempering temperature according to tempered-hardness, may further comprise the steps:

1) normalization tempered-hardness:

Whether the interval in the scope of judging tempering temperature and the step (1) in tempered-hardness-tempering temperature relation table is consistent, in this way, then confirms tempering temperature, as not being that the intermediate value of then getting original tempered-hardness scope is as the tempered-hardness H after standardizing _Tn

2) successively relatively the normalization after tempered-hardness H _TnWith the tempered-hardness upper limit and the tempered-hardness lower limit in tempered-hardness-tempering temperature relation table, judge the tempered-hardness H after standardizing _TnWhether on adjacent two tempered-hardness section boundaries on tempered-hardness-tempering temperature relation table;

3) the tempered-hardness H after normalization _TnNot on adjacent two tempered-hardness section boundaries, then find out the tempered-hardness H after the normalization _TnThe tempering temperature of the correspondence that the tempered-hardness that in tempered-hardness-tempering temperature relation table, belongs to is interval is interval, in this tempering temperature interval, calculates tempering temperature value T with approach based on linear interpolation _t

4) the tempered-hardness H after normalization _TnOn adjacent two tempered-hardness section boundaries, then judge whether it is the less energy-consumption principle, in this way, confirm that then tempering temperature is the low interval of temperature, as not being that then the through performance priority principle confirms that tempering temperature is the high interval of temperature;

5) the standardization tempering temperature is interval: step 3) obtains tempering temperature value T _t± 10 ℃ are standardization tempering temperature interval; The tempering temperature that obtains of step 4) is a value range, directly uses.

2. the method for a kind of definite tempering temperature according to claim 1 is characterized in that: in the said step 3), approach based on linear interpolation is calculated T _tMethod be:

$T_t=T_{\mathrm{hd}}+(H_{\mathrm{tn}}-H_d)\×\frac{T_{\mathrm{hu}}-T_{\mathrm{hd}}}{H_u-H_d}$

H _d: H _TnThe interval upper limit of the tempered-hardness of correspondence in tempered-hardness-tempering temperature relation table,

H _u: H _TnThe interval lower limit of the tempered-hardness of correspondence in tempered-hardness-tempering temperature relation table,

T _Hd: the H in tempered-hardness-tempering temperature relation table _dCorresponding tempering temperature lower limit,

T _Hu: the H in tempered-hardness-tempering temperature relation table _uThe corresponding tempering temperature upper limit;

3. the method for a kind of definite tempering temperature according to claim 1 is characterized in that: in the said step 4), the less energy-consumption priority principle is meant that selecting low tempering temperature, performance priority principle to be meant selects high tempering temperature.

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