Blank making method for 42CrMoA axial forging

A technology for forgings and shafts, which is applied in the blank-making field of 42CrMoA shaft forgings. It can solve problems such as inability to loosen, shrinkage cavity, and welding of central cracks, and achieve the effects of eliminating internal defects, low manufacturing costs, and long fatigue life.

Active Publication Date: 2015-04-22
CHONGQING CHANGZHENG HEAVY IND
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The conventional forging process cannot fully weld the internal porosity, shrinkage cavity, central crack, and air bubbles, and it is also difficult to improve harmful structures such as equiaxed crystal bands, columnar crystal bands, dendrite segregation, and regional segregation.

Method used

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  • Blank making method for 42CrMoA axial forging

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Embodiment Construction

[0018] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to the scope of the described embodiments.

[0019] see figure 1 , a billet making method for 42CrMoA shaft forgings, comprising the following steps:

[0020] The first step, continuous casting billet: continuous casting billet by continuous casting; among them, 42CrMoA pouring molten steel is obtained by the combination of ladle refining method and vacuum degassing method; the gas content in the billet meets the following requirements: hydrogen≤1.5ppm , Nitrogen≤70ppm, Oxygen≤20ppm; the content of non-metallic inclusions in the billet conforms to the following requirements according to the GB / T10561 standard rating: Class A fine ≤ 2.5, Class A coarse ≤ 2.0; Class B fine ≤ 2.0, Class B Coarse≤1.5 grade; C type fine≤1.0 grade, C type coarse≤1.0 grade; D type fine≤1.5 grade, D type coarse≤1.0 grade; DS type≤1.0 grade;

[0021] The s...

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PUM

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Abstract

The invention discloses a blank making method for a 42CrMoA axial forging. The method comprises the following steps: continuous casting of a billet: casting the billet continuously, wherein 42CrMoA pour steel is obtained by combining a ladle refining method and a vacuum degassing method, and the gas content and the nonmetallic inclusion content in the billet meet related requirements; heating and heat preservation: heating the billet stepwise at 750 plus or minus 10 DEG C and 1,250 plus or minus 10 DEG C while the heat preservation time is set; first firing forging: forging the billet by upsetting and stretching in sequence, wherein the upsetting ratio is greater than or equal to 2.5, and the stretching ratio is greater than or equal to 3.0; and second firing forging: heating the billet in a furnace to 1,250 plus or minus 10 DEG C, preserving heat, and forging the billet again by upsetting and stretching to form a blank, wherein the final forging temperature is controlled within 850-900 DEG C. The method provided by the invention has the benefits that the internal defects of the billet are eliminated, the metallographic structure is qualified, the fatigue life of the forging is long and the manufacturing cost is low.

Description

technical field [0001] The invention relates to a billet making method for alloy steel shaft forgings, in particular to a billet making method for 42CrMoA shaft forgings. Background technique [0002] The internal ultrasonic flaw detection and metallographic requirements of shaft forgings such as wind power and marine gearbox transmission are relatively high. Usually, 42CrMoA steel ingots are used for forging, which has few internal defects and relatively good internal quality of forgings, which can meet relevant technical requirements. However, since the ingot needs to remove water and risers, the utilization rate of raw materials is 75% to 80%. However, continuous casting billets do not need to remove water and risers, and the raw material utilization rate is more than 95%, and the price of 42CrMoA ingots and continuous casting billets is basically the same. Therefore, 42CrMoA continuous casting billets are used to produce shafts such as wind power and marine gearbox trans...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B21J5/00B21J1/00B21J1/06C21C7/00C21C7/10
Inventor 龚超
Owner CHONGQING CHANGZHENG HEAVY IND
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