Tubular member for exhaust gas treatment device and exhaust gas treatment device using the tubular member, and method of manufacturing tubular member for exhaust gas treatment device

A method of manufacturing a tubular member for an exhaust gas treatment device including a tubular main body made of a metal and an insulating layer formed at least on an inner peripheral surface of the tubular main body,

• the method comprising:
• preparing a tubular main body;
• and
• forming an insulating layer containing glass on an inner peripheral surface of the tubular main body,
• wherein the glass in the insulating layer has a content of an alkali metal element of 1,000 ppm or less.

A tubular member for an exhaust gas treatment device, comprising:

• a tubular main body made of stainless steel containing chromium;
• and
• an insulating layer formed at least on an inner peripheral surface of the tubular main body,
• wherein the insulating layer contains glass,
• wherein the glass contains silicon, boron, aluminum, and barium, and further contains one of magnesium, lanthanum, zinc, calcium, strontium, and a combination thereof,
• wherein the glass has a content of an alkali metal element of 1,000 ppm or less,
• wherein the insulating layer has a thickness of from 100 μm to 550 μm, and
• wherein the insulating layer has a pressing deformation temperature of 600° C. or more, which is defined as follows:
• the pressing deformation temperature is a temperature at which the insulating layer is deformed by 10% with respect to a thickness of the insulating layer in a thickness direction of the insulating layer when the insulating layer is heated at a temperature increase rate of 10° C./min while being pressed at a pressure of 0.1 MPa through use of an alumina needle of 1 mmΦ.