XDC04010502-保温工艺对G20CrNi2Mo钢带状组织的影响研究

G20CrNi2Mo 轴承钢工件易出现带状组织，严重降低其疲劳性能和服役寿命。本文采用金相显微镜（OM）、扫描电镜（SEM）、电子探针（EPMA）和电子背散射衍射（EBSD）等设备分析了G20CrNi2Mo 钢带状组织的形成原因，研究了保温温度和时间对带状组织形态和成分的影响规律。研究结果表明：（1）G20CrNi2Mo 钢锻造后的带状组织为先共析铁素体带，主要因凝固时 C 元素偏析增加部分区域的马氏体相变临界冷却速率降低所致。（2）G20CrNi2Mo 钢的带状组织在渗碳处理后可完全消除，但在低温碳氮共渗时存在无法消除的风险。在 780 ℃碳氮共渗时，其保温时间应大于 10 h。（3）G20CrNi2Mo锻料先采用 940 ℃保温 3 h 的方法正火预处理，再进行低温碳氮共渗，也可明显改善其带状组织。本文的研究结果为 G20CrNi2Mo 轴承工件渗碳/碳氮共渗热处理工艺的制定提供了数据支撑。

G20CrNi2Mo bearing steel workpieces are prone to forming banded structure, which severely deteriorates their fatigue performance and service life. This paper analyzes the formation mechanism of banded structure in G20CrNi2Mo steel using multiple characterization equipment including optical microscope (OM), scanning electron microscope (SEM), electron probe microanalyzer (EPMA), and electron backscatter diffraction (EBSD), and investigates the effects of holding temperature and time on the morphology and composition of the banded structure. The research results are as follows:
(1) The banded structure in as-forged G20CrNi2Mo steel consists of proeutectoid ferrite bands, which is mainly caused by C element segregation during solidification that reduces the critical cooling rate for martensitic transformation in specific regions.
(2) The banded structure in G20CrNi2Mo steel can be completely eliminated after carburizing treatment, but there is a risk of incomplete elimination during low-temperature carbonitriding. When carbonitriding is carried out at 780 ℃, the holding time should be more than 10 hours.
(3) Normalizing pretreatment with holding at 940 ℃ for 3 hours followed by low-temperature carbonitriding can also significantly improve the banded structure of as-forged G20CrNi2Mo steel.
The research findings of this paper provide reliable data support for the formulation of carburizing and carbonitriding heat treatment processes for G20CrNi2Mo bearing workpieces.

搜集汇总

背景与挑战

背景概述

该数据集是一项关于G20CrNi2Mo轴承钢带状组织的研究，重点探究保温工艺（包括温度和时间）对带状组织形态和成分的影响规律。研究发现，渗碳处理可完全消除带状组织，但低温碳氮共渗时需控制保温时间大于10小时，并建议采用正火预处理以改善组织。数据集为论文形式，提供材料科学领域的实验数据，旨在优化热处理工艺，提升钢材性能。