Hi @iviarcio, the NodeValue::setType() call does not change the actual payload of a Constant node, assuming this is what you are expecting to happen.
What you need to do is something like
template <typename T> static void rescaleBias(T *node, Function *F) {
  auto *bias = dyn_cast<Constant>(node->getBias());
  CHECK(bias) << "Expected bias would be Constant";
  Tensor floatBias = quantization::dequantizeTensor(bias->getPayload(), 
                                                    ElemKind::FloatTy);
  auto outTy = node->getResult().getType();
  Tensor newBias = quantization::quantizeTensor(floatBias, 
                                                {outTy->getScale(), outTy->getOffset()},
                                                outTy->getElementType());
  Constant *newConst = F->getParent()->createConstant(bias->getName().str() + "_converted",
                                                      std::move(newBias));
  bias->getOutput().replaceAllUsesOfWith(newConst->getOutput());
}