Unlock instant, AI-driven research and patent intelligence for your innovation.

Thermal treatment process for die steel H13 of automobile forged piece

A die steel, stage heat treatment technology, applied in the field of heat treatment, can solve the problems of surface thermal fatigue cracks, early brittle cracks or life reduction, mold surface carburization, etc. Effect

Active Publication Date: 2014-01-29
WUXI HONGDA HEAT TREATMENT FORGING
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This may cause carburization of the mold surface
In addition to covering up the real hardness of the mold itself, carburizing is the main defect that it is very easy to produce surface thermal fatigue cracks, which can cause early embrittlement or shorten the life. This situation is quite common in production practice. The thermal fatigue cracks of some forging molds, In fact, it is caused by carburization

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] Embodiment one: a heat treatment process of automobile forging die steel H13, comprising the following process steps:

[0015] (1) Put the mold steel (size: 420mm×190mm×190mm) into the heating furnace. The temperature of the heating furnace is <300°C, and the temperature is raised to 760°C. Methanol is introduced as a protective atmosphere, and the amount of the protective atmosphere is 40ml / min ;

[0016] (2) First, continue to raise the temperature of the heating furnace to 820°C for the first-stage heat treatment, and the heating time is 300 minutes; then raise the temperature of the heating furnace to 1020°C for the second-stage heat treatment, and the heating time is 380 minutes;

[0017] (3) Quenching and cooling: Cool the die steel in a quenching nitrate furnace at 160°C for 1.5 hours; then the die steel is naturally cooled to 120°C in the air for 1.5 hours after leaving the nitrate furnace;

[0018] (4) Tempering treatment: Temper the quenched and cooled die st...

Embodiment 2

[0020] Embodiment two: a heat treatment process of automobile forging die steel H13, comprising the following process steps:

[0021] (1) Put the mold steel (size: 200mm×220mm×150mm) into the heating furnace. The temperature of the heating furnace is <300°C, and the temperature is raised to 780°C. Methanol is introduced as a protective atmosphere, and the amount of the protective atmosphere is 30ml / min ;

[0022] (2) First, continue to raise the temperature of the heating furnace to 850°C for the first-stage heat treatment, and the heating time is 220 minutes; then raise the temperature of the heating furnace to 1050°C for the second-stage heat treatment, and the heating time is 300 minutes;

[0023] (3) Quenching and cooling: Cool the die steel in quenching oil at 50°C to 180°C for 22.5 minutes; naturally cool to 120°C in air for 1.5 hours.

[0024] (4) Tempering treatment: Temper the quenched and cooled die steel at 560°C for a holding time of 9 hours, and naturally cool to...

Embodiment 3

[0026] Embodiment three: a heat treatment process of automobile forging die steel H13, comprising the following process steps:

[0027] (1) Put the mold steel (size 1120mm×690mm×170mm) into the heating furnace, the temperature of the heating furnace is <300°C, raise the temperature to 770°C, feed methanol as the protective atmosphere, and the amount of the protective atmosphere is 40ml / min ;

[0028] (2) First, continue to raise the temperature of the heating furnace to 830°C for the first-stage heat treatment, and the heating time is 270 minutes; then raise the temperature of the heating furnace to 1030°C for the second-stage heat treatment, and the heating time is 360 minutes;

[0029] (3) Quenching and cooling: Cool the die steel in quenching oil at 60°C to 200°C for 25.5 minutes; naturally cool to 150°C in air for 2 hours;

[0030] (4) Tempering treatment: Temper the quenched and cooled mold steel at 570°C for 6 hours, and naturally cool to room temperature in the air aft...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a thermal treatment process for die steel H13 of an automobile forged piece. The thermal treatment process comprises the following process steps of: (1) holding the die steel into a heating furnace with temperature of less than 300 DEG C, heating to 760-780 DEG C and introducing a protective atmosphere; (2) heating the heating furnace to 820-850 DEG C to perform first-stage thermal treatment and then heating the heating furnace to 1,020-1,050 DEG C to perform second-stage thermal treatment; (3) cooling the die steel in a quenching nitrate furnace of 160-180 DEG C, wherein the cooling time is 1.5-2.5 hours and then naturally cooling to 120-160 DEG C, wherein the cooling time is 1.5-2.5 hours; (4) performing tempering treatment on the quenched and cooled die steel at 530-600 DEG C, preserving heat for 5-9 hours and naturally cooling to room temperature; and (5) repeating the step (4) for two to three times to finish the thermal treatment process of the die steel. According to the thermal treatment process, the machining allowance of a workpiece is reduced, the utilization rate of a material is improved, the uniformity of thermal treatment hardness is improved, and an auxiliary process for cleaning oxide skin on the surface of the workpiece is saved.

Description

technical field [0001] The invention relates to a heat treatment method, in particular to a heat treatment process for automobile forging die steel H13. Background technique [0002] H13 is a hot work die steel, the implementation standard GB / T1299-2000, the grade is 4Cr5MoSiV1; the chemical composition of H13 is (mass fraction%): C: 0.32~0.45, Si: 0.80~1.20, Mn: 0.20~0.50, Cr: 4.75~5.50, Mo: 1.10~1.75, V: 0.80~1.20, P≤0.030, S≤0.030, the balance is Fe. [0003] H13 forging die currently adopts heat treatment furnace types mainly including medium and high temperature box-type resistance furnaces, salt bath furnaces, and vacuum furnaces. The heat treatment of mold steel is rarely used in a protective atmosphere furnace with less oxidation. On the one hand, the life of the heating element and the heat-resistant steel alloy is short, and on the other hand, the selection of the shielding gas is a problem. In order to avoid oxidation and decarburization, it is generally heated...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C21D1/18C22C38/24
Inventor 蒋兴汪庆华
Owner WUXI HONGDA HEAT TREATMENT FORGING