Heat treatment and deformation compensation of steering joint mold

Heat treatment and deformation compensation of steering joint mold
After T6 treatment, the steering joint is normally bent by 0.1-0.3mm, and the mold side method is reverse pre compensation and locked furnace loading.
Deformation starts from quenching
After solution treatment and quenching, uneven cooling rates result in temperature gradients. The contraction at the junction of thickness and thinness is different, causing the long arm to bend.
The deformation amount is usually between 0.1-0.3mm. If it exceeds 0.3mm, the subsequent machining allowance is not sufficient to correct it, and it can only be shaped or scrapped.
The deformation direction is related to the furnace loading posture. Vertical furnace loading tends to bend towards one side in multiple directions, while horizontal furnace loading results in more dispersed deformation.
How to do pre compensation
Reserve deformation amount in reverse on the mold cavity. Reserve 70% -90% of the measured deformation and leave a portion for subsequent shaping.
Reservation requires data support. The first batch of trial production using standard molds, measuring the deformation before repairing the mold, is more reliable than reserving based on experience.
Xinfeng Mold will require customers to provide a furnace loading diagram for the heat treatment furnace in the steering joint mold project, based on which the compensation direction will be determined to avoid compensation reversal.
The loading method affects the results
When installing vertically, the weight of the parts will intensify bending. It is recommended to use specialized fixtures to support long arm components, with support points spaced no more than 150mm apart.
Excessive furnace loading leads to a decrease in temperature uniformity inside the furnace. It is recommended to control the uniformity of furnace temperature within ± 5 ℃, as exceeding the tolerance will cause unpredictable deformation.
The quenching water temperature also affects deformation. High water temperature, slow cooling, small deformation but insufficient strength; Low water temperature and significant deformation.
Allocation of machining allowance
When deformed by 0.3mm, a machining allowance of at least 0.8mm should be left. If the allowance is insufficient, black skin will be exposed locally after machining.
There is also a problem with excessive margin. The increase in cutting force makes it easy for thin-walled areas to be compressed and deformed, which in turn cannot guarantee accuracy.
Suggest dynamically adjusting the margin based on the measured deformation value, rather than unifying the entire batch. Batch management will increase workload, but it can reduce the scrap rate.
Plastic surgery and straightening
Parts with excessive deformation can be cold straightened or hot straightened. Cold straightening will generate residual stress and requires subsequent stress relief treatment.
The hot straightening temperature should not exceed the aging temperature of the material, otherwise it will damage the T6 strengthening effect.
School management is a remedial measure and cannot be used as a routine process. Incorporating the school administration into the standard process indicates that the previous control was not in place.
Verification and Closed Loop
Measure the first batch of three coordinates and take the maximum bending amount in the direction of the long arm. The data is sent back to the mold factory for correcting the pre compensation value.
During the mass production stage, 5% of each batch is randomly inspected to track the deformation trend. The stable trend indicates that the process is under control, and the trend drift requires checking the furnace condition.
How do suppliers cooperate
Mold factories and heat treatment factories should share furnace loading diagrams and deformation data. The data is not available, and pre compensation can only rely on guessing, with the cost of trial and error falling on the purchaser.
Suggest attaching a heat treatment requirement in the mold technology agreement, specifying the furnace loading posture, support position, and allowable deformation to reduce back and forth tearing.
Frequently Asked Questions
Question: How much deformation does the steering knuckle undergo during heat treatment?
Answer: Commonly 0.1-0.3mm, with longer arms being more prominent.
Question: How much pre compensation is left?
Answer: Take 70% -90% of the measured deformation.
Q: Does the furnace loading method have an impact?
Answer: Yes, the vertical and horizontal deformation directions are different.
Question: How much machining allowance is left?
Answer: When deformed by 0.3mm, it is recommended to leave at least 0.8mm.
Q: Can the deformation be straightened if it exceeds the tolerance?
Answer: Yes, but it is a remedy and cannot be used as a routine process.
Q: What is the requirement for furnace temperature uniformity?
Answer: It is recommended to stay within ± 5 ℃, as deformation beyond the tolerance is unpredictable.
Recommended search keywords
Steering joint heat treatment, steering joint deformation, aluminum alloy T6 treatment, steering joint mold, steering joint mold manufacturer, structural component mold customization, mold deformation compensation, heat treatment straightening, automotive structural components, steering joint processing