某公司使用45Cr9Si3材料采取热挤压工艺生产气门时出现了气门盘部裂口现象.本文通过OM及SEM+EDS等手段对缺陷样品进行分析,以及模拟材料在热挤压过程中的演变过程,分析出缺陷来源于原材料生产过程中的电渣工序,并提出了解决方案.

In order to study the morphology evolution of 1， 1‑diamino‑2， 2‑dinitroethylene （FOX‑7） particles under thermal stimulus and its influence on mechanical properties and mechanical sensitivities， four kinds of FOX‑7 particles with typical size and morphology differences were selected. By controlling heating time and temperature， the morphology， mechanical properties and mechanical sensitivities evolutions of FOX‑7 particles after heating were studied by scanning electron microscope， compressive stiffness experiment and mechanical sensitivities tests. The results show that the surface cracks of FOX‑7 particles appear after heating and returning to room temperature. With the increase of heating temperature or heating time， the surface cracks of large‑size particles （>100 μm） grow and break through ， thus the particles crack in layers and exfoliate. While， the surface cracks of small‑sized particles （<100 μm） do not grow with the increase of heating temperature or heating time. Kawakita equation was used to fit the compaction curves of FOX‑7 particles before and after heating. It is found that the modulus of FOX‑7 particles increase after heating， and the increase is even greater for small particle size. Under the condition of larger particle size， FOX‑7 has relatively low mechanical sensitivities， and still maintains low mechanical sensitivities after being heated and returning to room temperature. When the particle size is small， the mechanical sensitivities of FOX‑7 are relatively high， and after heating and returning to room temperature， the mechanical sensitivities increase significantly， which may be related to the greater increase of modulus.

ER307Ti is an austenitic stainless steel welding wire, which is used for welding titanium-containing stainless steel or dissimilar steel with heat and corrosion resistance requirements. The anti-intergranular corrosion ability of the weld has good mechanical properties. However, the addition of Ti element will form TiN inclusions,which can easily lead to rolling defects such as cracks and block drop under the action of rolling deformation stress.This paper studies the causes of defects and proposes solutions by means of macroscopic and metallographic defect analysis and theoretical calculation, and has achieved good results.

本文主要阐述了满足304HC不锈钢冷镦性能的主要控制指标及措施,得出夹杂物B、D、Ds类控制在1.0级以下,减少盘条表面缺陷和其横向截面缺陷深度不得超过0.05mm有利于减少304HC冷镦开裂比例,同时,对不同固溶方式的冷镦304HC的力学性能及显微组织进行了分析,离线固溶方式的304HC盘条由于强度低,塑性好,利于冷镦成型.